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  • Polymer and Materials Science  (112,478)
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  • Fisheries  (14,766)
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  • 1
    Publication Date: 2024-04-04
    Description: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact
    Keywords: living marine resources ; Forecasting ; prediction ; fish ; Fisheries ; Seasonal to Decadal Prediction ; Climate services ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RB Earth sciences::RBK Hydrology and the hydrosphere::RBKC Oceanography (seas and oceans)
    Language: English
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  • 2
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    Springer Nature | Palgrave Macmillan
    Publication Date: 2024-03-29
    Description: This open access book explores fishing livelihoods in the context of the wider contexts in which they are embedded. Drawing on case studies from across the Asia-Pacific region, the book highlights how fishing livelihoods are shaped by globalisation, social relationships and governance. The book concludes by showing how better understanding these relationships can contribute to governance for healthier ecosystems and social wellbeing. This is an open access book. This is an open access book.
    Keywords: Fisheries ; marine social science ; fishing livelihoods in the Asia-Pacific ; sustainable fishing ; environmental sustainability ; food security ; coastal conservation ; fish stocks ; fisheries governance ; Fishing livelihoods and social diversity ; Fishing livelihoods and wellbeing ; Open Access ; thema EDItEUR::J Society and Social Sciences::JP Politics and government::JPQ Central / national / federal government::JPQB Central / national / federal government policies ; thema EDItEUR::J Society and Social Sciences::JH Sociology and anthropology::JHB Sociology ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RN The environment ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RG Geography::RGB Physical geography and topography ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RN The environment::RNF Environmental management ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RG Geography::RGC Human geography
    Language: English
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 9 (1985), S. 39-52 
    ISSN: 0308-597X
    Keywords: Ecology ; Fisheries ; Marine resources
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 43-57 
    ISSN: 0308-597X
    Keywords: Atlantic ; Fisheries ; Management
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 9 (1985), S. 126-133 
    ISSN: 0308-597X
    Keywords: Fisheries ; Government ; USA
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 6
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 61-62 
    ISSN: 0308-597X
    Keywords: Fisheries ; Marketing ; UK
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 8 (1984), S. 137-150 
    ISSN: 0308-597X
    Keywords: Fisheries ; International organizations ; Management
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 8
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 7 (1983), S. 197-211 
    ISSN: 0308-597X
    Keywords: Fisheries ; Management ; Property rights
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 9
    Electronic Resource
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    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 219-235 
    ISSN: 0308-597X
    Keywords: Canada ; Fisheries ; Foreign relations
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 10
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 66-68 
    ISSN: 0308-597X
    Keywords: Fisheries ; Regional government organizations ; West Africa
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 11
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 9 (1985), S. 120-125 
    ISSN: 0308-597X
    Keywords: Exclusive Economic Zones ; Fisheries ; Law of the Sea
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 12
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 27-42 
    ISSN: 0308-597X
    Keywords: Fisheries ; International law ; United Nations Organization
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 13
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 131-139 
    ISSN: 0308-597X
    Keywords: Economic measurements ; Fisheries ; Pacific
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 14
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 7 (1983), S. 267-278 
    ISSN: 0308-597X
    Keywords: Environment ; Fisheries ; Resource management
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 15
    Electronic Resource
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    Amsterdam : Elsevier
    Marine Policy 6 (1982), S. 121-130 
    ISSN: 0308-597X
    Keywords: Atlantic ; Fisheries ; Management
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 16
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Marine Policy 8 (1984), S. 239-258 
    ISSN: 0308-597X
    Keywords: Antarctica ; Fisheries ; Krill
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 17
    Electronic Resource
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    Amsterdam : Elsevier
    Marine Policy 9 (1985), S. 220-236 
    ISSN: 0308-597X
    Keywords: Fisheries ; Resource economics, UK
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Political Science , Law
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  • 18
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    Springer
    Agriculture and human values 17 (2000), S. 125-139 
    ISSN: 1572-8366
    Keywords: Environment ; Fisheries ; Fordism ; Nation-State ; Regulation ; Supranational State ; Transnational corporations ; Transnational State
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract This analysis uses an analytical frameworkgrounded in political economy perspectives of theglobalization of the agro-food sector combined with acase study approach focusing on the Marine StewardshipCouncil (MSC) to inform discussions regarding thecharacteristics of societal regulation in thepost-Fordist era. More specifically, this analysisuses the case of the emergence of the MSC toinvestigate propositions regarding the existence of,and location of, nascent forms of a transnationalState. The MSC proposes to regulate the certificationof sustainable fisheries at the global level throughan eco-labeling program. The MSC was created in 1996by the transnational environmental organization theWorld Wildlife Fund and the transnational corporationUnilever. The emergence of the MSC has generatedheated discussion in fisheries management circles thatis in general divided along North/South lines. Thisanalysis indicates that the case of the MSC providesvaluable insights into the possible characteristics ofsupranational regulatory mechanisms that might emulatethe role of the nation-State in the post-Fordist era.
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  • 19
    ISSN: 1432-1009
    Keywords: Reservoir ; Fisheries ; Breeding and wintering waterbirds ; Raising water levels ; Habitat change
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A new, higher dam was installed at Kerkini Reservoir in 1982, causing habitat and landscape disruption. A decrease in the area of grassland and shallow water areas, the rapid disappearance of reedbeds, the appearance of beds ofNymphaea, and the disappearance of half the forest area were all observed between 1982 and 1991. With the new hydrological regime, a lacustrine system was created, with an extensive, rather deep (4–8 m), pelagic zone favorable for the development of coarse fish species throughout the year. After 1982, an increase in fishing effort and a change in the relative abundance of fish species in the catch, including the disappearance of eels and wels, were observed. The impact of the rise in the water level of breeding aquatic birds led to a general decline in species typical of marshy habitats in favor of species preferring deeper open water habitats. A decrease was recorded in bird species that feed largely on invertebrates and to a lesser extent fish (e.g., glossy ibis) and that require extensive shallow feeding areas. There was a decline in geese, whose nests were regularly flooded, and a major increase in piscivorous birds, particularly diving birds (e.g., cormorants), which prefer deeper open water and benefitted directly from the large increase in coarse fish biomass. The disappearance of birds breeding in flooded meadows (e.g., black-winged stilts) and of those restricted to reedbeds (e.g., marsh harrier) occurred from 1983. Over the same period, the changes in populations of wintering birds at Kerkini were different from those occurring in other wetlands in northern Greece. The changes recorded in the populations of wintering birds at Kerkini did not therefore result from overall regional trends but from the major habitat modifications that occurred to this wetland. As for breeding birds, strictly piscivorous species increased greatly as a result of the increased availability of fish, but also due to the appearance of many suitable night roosting sites (flooded trees) and to the great increase in the area of open water greater than 2 m deep. Today, Kerkini has become the most important breeding site in Greece for a majority of colonial waterbirds. In contrast, wintering shorebirds practically disappeared. The many changes recorded in the status of breeding and wintering birds at Kerkini can mostly be explained by the changes that occurred in the functioning of the ecosystem and in the habitat structure following the inauguration of the new hydrological regime. These changes did not all occur at the same time: some were immediate and others required a delay before they could be detected.
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  • 20
    ISSN: 1432-1009
    Keywords: Fisheries ; Phosphorus ; Contaminants ; Ecosystem ; Management ; Simulation model ; Great Lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A simulation model was developed to describe linkages among fish food web, nutrient cycling, and contaminant processes in the southern basin of Lake Michigan. The model was used to examine possible effects of management actions and an exotic zooplankter (Bythotrephes) on Lake Michigan food web and contaminant dynamics. The model predicts that contaminant concentrations in salmonines will decrease by nearly 20% ifBythotrephes successfully establishes itself in the lake. The model suggests that this decrease will result from lowered transfer efficiencies within the food web and increased flux of contaminants to the hypolimnion. The model also indicates that phosphorus management will have little effect on contaminant concentrations in salmonines. The modeling exercise helped identify weaknesses in the data base (e.g., incomplete information on contaminant loadings and on the biomass, production, and ecological efficiencies of dominant organisms) that should be corrected in order to make reliable management decisions.
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  • 21
    Electronic Resource
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    Environmental management 7 (1983), S. 151-160 
    ISSN: 1432-1009
    Keywords: Grass carp ; Biological control ; Nuisance aquatic weeds ; Fisheries ; Aquaculture ; Reproductive requirements ; Arkansas management plan ; Sterile hybrids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Grass carp (Ctenopharyngodon idella Val.) were introduced into the United States in 1963 as potential biological control agents for nuisance aquatic weeds. Since that time an oftentimes bitter controversy has raged over its effects on sportfishing, and its possible natural reproduction and naturalization in North America. This review considers the history, ecology, and present status of grass carp in the United States in light of the voluminous scientific research conducted since its importation. Particular attention is given to the role of grass carp in the fisheries management plans of Arkansas. Recent development of a sterile, triploid grass carp hybrid may lead to widespread use of grass carp to control nuisance aquatic weeds in culturally eutrophicated waters of the United States.
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  • 22
    ISSN: 1432-1009
    Keywords: Flushing ; Scouring ; Channel Maintenance ; Fisheries ; Trinity River
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The operation of Trinity and Lewiston Dams on the Trinity River in northern California in the United States, combined with severe watershed erosion, has jeopardized the existence of prime salmonid fisheries. Extreme streamflow depletion and stream sedimentation below Lewiston have resulted in heavy accumulation of coarse sediment on riffle gravel and filling of streambed pools, causing the destruction of spawning, nursery, and overwintering habitat for prized chinook salmon (Salmo gairdnerii) and steelhead trout (Oncorhynchus tschawytscha). Proposals to restore and maintain the degraded habitat include controlled one-time remedial peak flows or annual maintenance peak flows designed to flush the spawning gravel and scour the banks, deltas, and pools. The criteria for effective channel restoration or maintenance by streambed flushing and scouring are examined here, as well as the mechanics involved. The liabilities of releasing mammoth scouring-flushing flows approximating the magnitude that preceded reservoir construction make this option unviable. The resulting damage to fish habitat established under the postproject streamflow regime, as well as damage to human settlements in the floodplain, would be unacceptable, as would the opportunity costs to hydroelectric and irrigation water users. The technical feasibility of annual maintenance flushing flows depends upon associated mechanical and structural measures, particularly instream maintenance dredging of deep pools and construction of a sediment control dam on a tributary where watershed erosion is extreme. The cost effectiveness of a sediment dam with a limited useful economic life, combined with perpetual maintenance dredging, is questionable.
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  • 23
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    Environmental management 20 (1996), S. 523-539 
    ISSN: 1432-1009
    Keywords: Water control ; Floodplain ; Fisheries ; Bangladesh ; Chandpur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Bangladesh is a very flat delta built up by the Ganges—Brahmaputra—Meghna/Barak river systems. Because of its geographical location, floods cause huge destruction of lives and properties almost every year. Water control programs have been undertaken to enhance development through mitigating the threat of disasters. This structural approach to flood hazard has severely affected floodplain fisheries that supply the major share of protein to rural Bangladesh, as exemplified by the Chandpur Irrigation Project. Although the regulated environment of the Chandpur project has become favorable for closed-water cultured fish farming, the natural open-water fishery loss has been substantial. Results from research show that fish yields were better under preproject conditions. Under project conditions per capita fish consumption has dropped significantly, and the price of fish has risen beyond the means of the poor people, so that fish protein in the diet of poor people is gradually declining. Bangladesh is planning to expand water control facilities to the remaining flood-prone areas in the next 15–20 years. This will cause further loss of floodplain fisheries. If prices for closed-water fish remain beyond the buying power of the poor, alternative sources of cheap protein will be required.
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  • 24
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    Environmental management 3 (1979), S. 133-144 
    ISSN: 1432-1009
    Keywords: Coastal zone Management ; Fisheries ; Marshes ; Wetlands ; Louisiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract This paper examines causes and consequences of wetland losses in coastal Louisiana. Land loss is a cumulative impact, the result of many impacts both natural and artificial. Natural losses are caused by subsidence, decay of abandoned river deltas, waves, and storms. Artificial losses result from flood-control practices, impoundments, and dredging and subsequent erosion of artificial channels. Wetland loss also results from spoil disposal upon wetlands and land reclamation projects. Total land loss in Louisiana's coastal zone is at least 4,300 ha/year. Some wetlands are converted to spoil banks and other eco-systems so that wetland losses are probably two to three times higher. Annual wetland losses in the Barataria Bay basin are 2.6% of the wetland area. Human activities are the principal determinants of land loss. The present total wetland area directly lost because of canals may be close to 10% if spoil area is included. The interrelationship between hydrology, land, vegetation, substrate, subsidence, and sediment supply are complicated; however, hydrologic units with high canal density are generally associated with higher rates of land loss and the rate may be accelerating. Some cumulative impacts of land loss are increased saltwater intrusion, loss of capacity to buffer the impact of storms, and large additions of nutrients. One measure of the impact is that roughly $8–17 × 106 (U.S.A.) of fisheries products and services are lost annually in Louisiana. Viewed at the level of the hydrologic unit, land loss transcends differences in local vegetation, substrate, geology, and hydrology. Land management should therefore focus at that level of organization. Proper guideline recommendations require an appreciation of the long-term interrelations of the wetland estuarine system.
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  • 25
    ISSN: 1573-5133
    Keywords: Chondrichthyes ; Elasmobranchs ; Fisheries ; Ageing methods ; Growth rates ; Gestation periods ; Maturity ; Vertebral bands ; Weight-length relationships ; Life histories
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The silky shark, Carcharhinus falciformis, and scalloped hammerhead, Sphyrna lewini, represent 〉80% of the shark by-catch of the winter swordfish/tuna longline fishery of the northwestern Gulf of Mexico. This catch represents a potential supplemental fishery, yet little is known of the life histories of the two species. This report relates reproductive biology data to age and growth estimates for 135 C. falciformis and 78 S. lewini. Unlike other regional populations, C. falciformis in the Gulf of Mexico may have a seasonal 12 month gestation period. Males mature at 210–220 cm TL (6–7 yr); females at 〉225 cm TL (7–9 yr). Application of age at length data for combined sexes produced von Bertalanffy growth model parameter estimates of L∞ = 291 cm TL, K = 0.153, t0 = −2.2 yr. Adult male S. lewini outnumbered adult females in catches because of differences in the distributions of the sexually segregated population. Males mature at 180 cm TL (10 yr); females at 250 cm TL (15 yr). von Bertalanffy parameter estimates for combined sexes of this species were L∞ = 329 cm TL, K = 0.073, to = −2.2 yr.
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  • 26
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    Environmental biology of fishes 2 (1977), S. 241-259 
    ISSN: 1573-5133
    Keywords: Production ; Fisheries ; Population dynamics ; Energetics ; Fishes ; Competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Production rates of seven species of fishes were determined for one year in a 0.95 ha pond. Total annual production of all fishes in the pond was 209 g m−2y−1 (after the subtraction of 16.2 g m−2y−1 of negative production). Over 90% of the production occurred in the months of June through September, with young-of-the-year fishes contributing 84% of the total. When Y of Y fishes shifted to benthic diets in the spring, the small biomass of benthos available could not sustain the large biomas of fish. Severe competition for the available food then resulted in decreased production rates for the entire fish taxocene.
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  • 27
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    Environmental biology of fishes 7 (1982), S. 177-180 
    ISSN: 1573-5133
    Keywords: Temperature ; Behavior ; Ecology ; Fisheries ; Fish ; Marine juveniles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Sixteen yearling winter flounder, tested individually for 3-day periods in electronic shuttleboxes, voluntarily occupied an 8–27°C range of temperature, with a modal final thermal preferendum of 18.5°C (mean 18.7°C, median 19°C, midpoint 17.5°C, s.d. 1.9°C, S k + 0.33). The locomotor activity pattern of the yearling fish in the laboratory was markedly nocturnal, with mean hourly nocturnal activity exceeding mean hourly diurnal activity by a factor of 3.4. Maximum activity occurred at 0300 EST, minimum activity at 1400 EST. While activity generally increased with temperature, a local activity minimum occurred at 18.7°C, coinciding with the 24-hour mean final thermal preferendum. Comparison of these laboratory data with previously published field data suggest that behavioral responses to temperature and light play significant roles in determining age- and size-specific differences in seasonal depth stratification and onshore-offshore distributions in this species.
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  • 28
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    Environmental biology of fishes 30 (1991), S. 253-271 
    ISSN: 1573-5133
    Keywords: Rockfish ; Longevity ; Reproductive value ; Fisheries ; Scorpaenidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The characteristics of lightly and heavily exploited Pacific ocean perch,Sebastes alutus, stocks are evaluated relative to the predictions of life history theory. These long-lived species (50–100 year lifespan) show limited phenotypic plasticity and have little buffering against the effects of reduced lifespan. Reduced stock abundance has generated some compensatory increase in growth rate. Length at first maturity varies only slightly with increased growth rate, although age at maturity may decrease by 1–4 years. Grooth increases yield larger (15–20%) size at age and increased reproductive effort at younger ages, but lower size-specific fecundity for these faster-growing fish. This suggests an energy allocation protocol favouring growth over reproduction in these long-lived animals. Rockfishes have late recruitment to fisheries (ages 10–15), and the detection time for results of management actions is equally long. Their vulnerability to overfishing means that indices of population changes, more representative of fishing effects than the catch rate index presently used, are required. Reproductive value indices are shown to be extremely sensitive and continuous with population abundance changes. Their incorporation into monitoring programs would permit more timely evaluation of management actions. Management policies developed for shorter-lived species are shown to be inappropriate for rockfishes. The need for an improved match in the time frame of the species' life history, and that of management strategies, is stressed.
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  • 29
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    Environmental biology of fishes 35 (1992), S. 187-203 
    ISSN: 1573-5133
    Keywords: California ; Elasmobranchs ; Exploitation ; Fisheries ; Life history ; Tagging ; Triakidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The age, growth, and sexual maturation of the leopard shark, Triakis semifasciata, from central California were studied. Growth band counts in vertebral centra of 162 leopard sharks produced von Bertalanffy growth curves with L∞, K. and to parameters of 1536 mm. 0.082, and -2.31, respectively, for both sexes combined. The L8 value for females (1602 mm TL) was slightly but insignificantly higher than for males (1499 mm TL), but the K and to values were almost identical. Seasonal changes in size modes of young-of-the-year leopard sharks, centrum edge characteristics, and growth and tetracycline mark-recapture from the field were used to validate annual deposition of vertebral centrum band pairs. Sexual maturity was evaluated by the gonads and presence of sperm and eggs; males mature at 7 yr and at about 63% of asymptotic length, and females mature at 10 yr, and at about 72% of asymptotic length. This slow growth, late maturity, and relatively low fecundity may increase their susceptibility to over-exploitation.
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  • 30
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    Environmental biology of fishes 45 (1996), S. 219-235 
    ISSN: 1573-5133
    Keywords: Ecology ; Behaviour ; Evolution ; Cichlids ; Fisheries ; Conservation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Ecological conditions in tropical lacustrine systems are considered by focusing on the evolution, maintenance, exploitation and vulnerability of fish communities in the African Great Lakes. The exceptionally high biodiversities in the littoral/sublittoral zones of the very ancient, deep, clear, permanently stratified rift lakes Tanganyika and Malawi, are contrasted with the simpler systems in their pelagic zones, also with biodiversity in the much younger, shallower Victoria, the world's largest tropical lake.
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  • 31
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    Environmental biology of fishes 23 (1988), S. 141-154 
    ISSN: 1573-5133
    Keywords: Cyanide ; Diversity ; Development ; Ecology ; Environment ; Fisheries ; Pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The biological diversity and productivity of Philippine coral reefs are threatened by siltation, destructive fishing methods, coral and shell collecting and overfishing. Destructive fishing includes: the widespread, illegal use of explosives; poisons such as sodium cyanide; muro-ami and kayakas fishing; and trawling. The recent decline in catch rates threatens the livelihood of 700 000 near-shore subsistence fishermen who catch 55% of the total landings. The new government under Corazon Aquino wishes to protect the marine environment through the creation of a viable marine conservation management plan, enforcement of existing laws and through cooperation between government, non-government and international agencies to provide education and research. The Department of Agriculture, which has the authority for fisheries, has designated the International Marinelife Alliance as the lead non-government agency involved with fund raising, net-training and finding alternatives to destructive fishing methods.
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  • 32
    ISSN: 1573-5133
    Keywords: Cyprinids ; Ethiopia ; Morphotypes ; Food-niche ; Biodiversity ; Feeding ; Evolution ; Fisheries ; Resource partitioning ; Piscivory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis In October–December 1990, the large barbs (Barbus) that contribute more than 35% of the catch in lake Tana (northern Ethiopia) were studied. Previous authors (Rüppell 1837, Boulenger 1902,1911, Bini 1940) described from 6 to 23 (sub)species for the lake. Banister (1973) lumped all of these into one subspecies: Barbus intermedius intermedius Rüppell,1837. We found that the Lake Tana Barbus could be readily categorized in at least 13 discrete morphotypes, some of which were already distinguished by local fishermen. None of the known descriptions are adequate to distinguish the barbs unambiguously, which is important for monitoring and management of developing fisheries. Intermediates between morphotypes were rare (〈 10%). By applying canonical discriminant analysis on a set of 17 morphometric characters (including some directly associated with feeding) our initial morphotype-distinction was confirmed. Also, differences between the morphotypes in distribution, related to depth and substratum were found, as well as differences in intestinal contents, a key to the food-niche. The high number of piscivorous morphotypes (8 out of 13) was striking as piscivory is relatively rare among cyprinids. Piscivory was found to be highly correlated with morphological (feeding related) characters. The presence of discrete morphotypes, that also differ in food-niche and distribution, strongly suggests that several distinct populations exist, that may be (partly or completely) reproductively segregated. Knowledge about these populations, that may represent separate units of fish stock, is of crucial importance for the management of sustainable fisheries and protection of the biodiversity in Lake Tana. It is possible that several species or even a unique cyprinid species flock are present, that urgently need protection.
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  • 33
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    Springer
    Environmental biology of fishes 27 (1990), S. 303-308 
    ISSN: 1573-5133
    Keywords: Fish introductions ; Africa ; Cichlids ; Barbus ; Haplochromis ; Lake management ; Fisheries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Cyprinid fishes apparently constituted the major part of the original fish fauna in Lake Luhondo, Rwanda, at least until 1934. At that time only three species, all cyprinids, were known from the lake:Barbus neumayeri, a small barbel, very common in the lake (described from the lake asBarbus luhondo) and two larger cyprinid species:Barbus microbarbis andVaricorhinus ruandae. These two large species were probably not very common in the lake. Between 1935 and 1938 some youngTilapia were introduced into Lake Luhondo. Since then and certainly since 1952 the large cyprinids seem to have disappeared completely from the lake. The smallBarbus neumayeri has become extremely rare; at present it survives only in some small tributaries of the lake. In the lake itselfTilapia andHaplochromis species are now the dominant fauna. A survey of the available information is given.
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  • 34
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    Environmental biology of fishes 43 (1995), S. 381-391 
    ISSN: 1573-5133
    Keywords: Fisheries ; Irrigation ; Reproductive seasonality ; Sarotherodon galilaeus ; Species richness ; Water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis A preliminary study of the ecology and commercial fish catches was carried out in the Toho-Todougba, Ahouangan and Dati lakes (1500 ha) in southern Benin (West Africa) over a period of 18 consecutive months. Water quality, species richness, and the reproductive biology of the dominant species, Sarotherodon galilaeus, were examined. Unlike Lagoon Toho-Todougba, lakes Ahouangan and Dati are less favourable for fish production because of their high total iron content and their relative low pH. The study revealed the existence of 19 species belonging to eleven (11) families: 16 species in Lagoon Toho-Todougba,12 in Lake Ahouangan, and 7 in Lake Dati. Lakes Ahouangan and Dati had a relatively high faunal similarity whereas Lagoon Toho-Todougba exhibited a relatively low faunal similarity with the former systems. In Lagoon Toho-Todougba, six cichlid species were the most important component of the fishery: Sarotherodon galilaeus, Tilapia guineensis, T. zillii, T. mariae, Chromidotilapia guntheri, Hemichromis fasciatus. Three catfish species Chrysichthys auratus, Clarias agboyiensis, and Clarias lazera were harvested in low abundances. Some other fish, such as Polypterus senegalus senegalus, Protopterus annectens and Heterotis niloticus were captured sporadically, with H. niloticus appearing more consistently in catches than the others. Although not abundant, Gymnarchus niloticus and the African pike, Hepsetus odoe, were almost always present in the catches. Ctenopoma kingsleyae appeared only in Ahouangan. Some predatory species, such as Notopterus afer and Xenomystus nigri, are encountered only in lakes Ahouangan and Dati. In Lagoon Toho-Todougba, Sarotherodon galilaeus had a sex ratio (♂: ♀) of 0.49:1, and size at maturation was estimated as 12.3 cm TL. The spawning period extended from May to September with the peak occurring in July. Fecundity was correlated to log-body length (r = 0.74) and log-body weight (r = 0.76). Fish catches were estimated at 389 kg ha−1 year−1; about 73% of which was Sarotherodon galilaeus. The overexploitation of juvenile fish and the use of this lagoon for the irrigation of palm tree plantations have reduced fish recruitment and mean size.
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  • 35
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    Environment, development and sustainability 2 (2000), S. 277-304 
    ISSN: 1573-2975
    Keywords: Systems of Knowledge ; Local Knowledge ; Fisheries ; Resource Management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Sociology
    Notes: Abstract During the last 20 years, the existence of rich systems of local knowledge, and their vital support to resource use and management regimes, has been demonstrated in a wide range of biological, physical and geographical domains, such as agriculture, animal husbandry, forestry and agroforestry, medicine, and marine science and fisheries. Local knowledge includes empirical and practical components that are fundamental to sustainable resource management. Among coastal-marine fishers, for example, regular catches and, often, long-term resource sustainment are ensured through the application of knowledge that encompasses empirical information on fish behaviour, marine physical environments, fish habitats and the interactions among ecosystem components, as well as complex fish taxonomies. Local knowledge is therefore an important cultural resource that guides and sustains the operation of customary management systems. The sets of rules that compose a fisheries management system derive directly from local concepts and knowledge of the resources on which the fishery is based. Beyond the practical and the empirical, it is essential to recognise the fundamental socio-cultural importance of local knowledge to any society. It is through knowledge transmission and socialisation that worldviews are constructed, social institutions perpetuated, customary practices established, and social roles defined. In this manner, local knowledge and its transmission, shape society and culture, and culture and society shape knowledge. Local knowledge is of great potential practical value. It can provide an important information base for local resources management, especially in the tropics, where conventionally-used data are usually scarce to non-existent, as well as providing a shortcut to pinpoint essential scientific research needs. To be useful for resources management, however, it must be systematically collected and scientifically verified, before being blended with complementary information derived from Western-based sciences. But local knowledge should not be looked on with only a short-term utilitarian eye. Arguments widely accepted for conserving biodiversity, for example, are also applicable to the intellectual cultural diversity encompassed in local knowledge systems: they should be conserved because their utility may only be revealed at some later date or owing to their intrinsic value as part of the world's global heritage. At least in cultures with a Western liberal tradition, more than lip-service is now being paid to alternative systems of knowledge. The denigration of alternative knowledge systems as backward, inefficient, inferior, and founded on myth and ignorance has recently begun to change. Many such practices are a logical, sophisticated and often still-evolving adaptation to risk, based on generations of empirical experience and arranged according to principles, philosophies and institutions that are radically different from those prevailing in Western scientific circles, and hence all-but incomprehensible to them. But steadfastly held prejudices remain powerful. In this presentation I describe the 'design principles' of local knowledge systems, with particular reference to coastal-marine fishing communities, and their social and practical usefulness. I then examine the economic, ideological and institutional factors that combine to perpetuate the marginalisation and neglect of local knowledge, and discuss some of the requirements for applying local knowledge in modern management.
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  • 36
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    Angewandte Makromolekulare Chemie 150 (1987), S. 189-192 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A morphological study was made to examine the friction and wear mechanisms of ultrahigh molecular weight polyethylene in air and water by means of transmission electron microscopy of a carbon replica film of a very thin layer of the polymer surface slid against a steel ball. Electron diffractions revealed that a molecular orientation with a typical fiber pattern was formed in the friction in air, while thin ribbon-like crystals with particular crystal orientations were formed in water in a way that the sliding took place on the crystallographic a - c plane, giving rise to a low friction coefficient of the polymer.
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  • 37
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    Angewandte Makromolekulare Chemie 150 (1987), S. 137-150 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurde der relative Wirkungsgrad von fünf handelsüblichen Stabilisatoren bei Photooxidation und thermischer Alterung von Polypropylen (PP) anhand der Änderungen der mechanischen Eigenschaften untersucht. Es wurden Polypropylenproben mit unterschiedlichem Anteil an Cyasorb UV-531 hergestellt (bezeichnet als PC0.5-31, PC1-31, PC1.5-31 und PC2-31). Der Einfluß der Photooxidation auf das thermische Verhalten ist mit Hilfe der Differentialscanningkalorimetrie und durch thermogravimetrische Analysen untersucht worden. 2-Hydroxy-4-n-octyloxybenzophenon (2 Gew.-%) war am wirksamsten, Polypropylen, gegen Verfärbung und Brüchigkeit zu stabilisieren. Bei einer Probe mit 1% Stabilisatorzusatz fanden sich nach 32 h Bestrahlung noch 81% des ursprünglichen Wertes der Streckgrenze gegenüber 18% bei unstabilisiertem PP.
    Notes: The relative effectiveness of five commercially available stabilizers on the photooxidation and thermal ageing of polypropylene (PP) was investigated by following changes in mechanical properties. Samples of PP containing different percentages of Cyasorb UV-531 were prepared (designated as PC0.5-31, PC1-31, PC1.5-31, and PC2-31, respectively). The effect of photooxidation on thermal behaviour was investigated by differential scanning calorimetry and thermogravimetric analysis. 2-Hydroxy-4-n-octyloxy benzophenone (2% w/w) was most effective in stabilizing PP towards discolouration and brittleness. After 32 h irradiation, 81% retention in yield strength was observed in case of PC1-31 against 18% in case of PP.
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  • 38
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effects of the nature of the polyols used in polyurethane (PUR) synthesis on the structural transformations after ageing by UV irradiation has been studied. The investigations were performed on PUR prepared from polyester and polyether diol oligomers.The characterization of the samples before and after ageing in view of the structural changes, which influence the course of the photooxidative degradation and photocrosslinking as well as in view of changes of mechanical properties has been done. Comparative investigations were performed by spectroscopic and viscometric measurements.The results show pronounced heterogeneity of the degradative reactions, including the existence of crosslinking processes and producing thus very inhomogeneous polymeric material. The course and the intensity of photooxidative degradation of PUR differ together with changes of mechanical properties depending whether polyester or polyether polyol have been used. The processes of photooxidative degradation is less expressed in polyesterurethane then in polyurethane based on polyether, under the same conditions of experiments. Different structures of polyester diols caused the various ageing behaviour of PUR too.
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  • 39
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: QUALIFICATION OF HALS COMPOUNDSA complex method of examination has been developed suitable for the qualification of light stabilizers; by this method, according to experience, the efficacy of HALS compounds can be extensively and expediently characterized.Several light stabilizers of the HALS-type were examined and qualified, used alone or together with a UV-absorber.It has been found that, when selecting the appropriate structure for a given polymer, the weatherability of polyolefine foils is effectively increase to six-eightfold; the increase is even tenfold when the stabilizer is combined with a benzophenone-type compound.As a utilization of these experiences, a contract with the industry, led to the production of an LDPE based agricultural foil with a life-time of several years.
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  • 40
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Natural hail impact tests are scarcely available because hailstorms are limited to a small area and cannot be predicted regarding time, place and intensity. Therefore we relied on laboratory tests simulating natural hailstones by polyamide balls (5-50 mm dia.) whose final velocity could be varied according to meteorological data. So the influence of diameter (weight) and velocity of the artificial hailstones could be taken into consideration independently.The energy of damage or equivalent natural hailstone diameter were determined for 16 mm double skin sheet from PMMA as 0.2 J (14 mm dia.) for star shaped cracks and 2 J (26 mm dia.) for holes. These values do not significantly decrease after 10 years weathering. 10 mm double skin sheets from PC show an extremly high energy of damage of abt. 10 J (38 mm dia.) which decreases to a medium level of 2 J (26 mm dia.) after several years weathering. This decrease is remarkably reduced by weather resistant protective coating.As hailstorms consist to more than 80% of hailstones below 10 mm dia. (0.04 J) the mentioned sheet materials are quite hail resistant also after long weathering periods, but they cannot withstand an extreme hail catastrophe as in Munich July 12, 1984.
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  • 41
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The influence of the specimen temperature on many ageing processes is well known. Two aspects is dealt with: -Measurements of the specimen temperature on several positions of a specimen in commercial weathering devices at different exposure conditions. Technical measures to achieve to uniform ageing at all positions of a planar and homogeneous specimen. Examples from practical use.-Changing specimen temperatures (+60°C to -20°C) during the course of accelerated weathering, i.e. a combination of conventional accelerated weathering with a temperature cycle test.
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  • 42
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: An Folien (Dicke 100 pm) aus isotaktischem Polypropylen mit verschiedenen Antioxidansgehalten (0,0% bis 0,1%) wird die thermooxidative Alterunq mit der isothermen Langzeit-Differential-Thermo-Analyse (ILDTA) bis zu Temperaturen weit unter dem Kristallitschmelzbereich verfolqt und die Messwerte mit Ergebnissen aus dem Zeitstand-Zugversuch korreliert. Dabei zeigt sich, daß aus Messunqen mit der ILDTA bereits vor Einsetzen der autokatalytischen Zersetzunq sreaktion Ruckschlüsse auf die thermische Vorqeschichte der Proben und Aussagen auf das rnit einem Abfall der mechanischen Eigenschaften verbundene Ende der thermo-oxidativen Stabilität des Polymeren getroffen werden können.Weiters bietet die ILDTA die Moglichkeit, durch den direkten Zusamenhang zwischen Oxidationszeit und Antioxidansögehalt die örtliche Stabilisatorverteilung in Platten und in Folien zu bestimmen und damit Diffusionsvorqange zu verfolgen.
    Notes: Thermo-oxidative ageing processes were investigated in films (100 μm thick) made from isotactic polypropylene with different antioxidant concentrations between 0% and 0.1% using isothermal long-term differential thermal analysis (ILDTA). The end of the oven life of polypropylene coincided with the loss of mechanical properties which was confirmed by tensile tests at temperatures far below the crystallite melting range. Already prior to the beginning of autocatalytic decomposition, ILDTA experiments permits conclusions to be drawn on the thermal history of the specimens and statements made regarding the end of thermo-oxidative stability of the polymer, which is accompanied by a deterioration in the mechanical properties.In consequence of the correlation between oxidation time and antioxidant concentration the local antioxidant concentration in sheets or films can be measured by ILDTA. Thus, investigating the diffusion of an antioxidant in polypropylene using ILDTA is possible.
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  • 43
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Größenverteilungsfunktion von Dispersionen mit extrem breiter Verteilung (Durchmesserbereich 20 〈 D 〈 2000 nm) kann in der analytischen Ultrazentrifuge (AUC) nicht durch eine Standardmethode, z. B. durch Messung der Trübung τ bei einer einzigen Konzentration, bestimmt werden, weil sich die spezifische Trübung τ/c von sehr kleinen und sehr großen Teilchen zu stark unterscheidet. Um dieses Problem zu lösen, haben wir eine neue AUC-Technik, die sogenannte Coupling-PSD-Technik entwickelt. Dabei werden zwei unterschiedliche Konzentrationen derselben Dispersion gleichzeitig in einem einzigen AUC-Lauf vermessen und zwei korrespondierende Lichtintensitiit-Zeit-Kurven aufgezeichnet. Bei einer niedrigen Standardkonzentration cs werden hauptsachlich die größeren Teilchen erfaßt während bei einer 5 bis 30 mal heheren Konzentration ch vor allem die kleineren Teilchen registriert werden. Die beiden I(t)-Kurven werden mathematisch verkniipft und unter Verwendung des Stokeschen Gesetzes und der Streutheorie von Mie für homogene isotrope Kugeln in die gesuchte breite Verteilungsfunktion umgerechnet. Wir benutzen eine mit einem 8-Zellen-Rotor und einem Multiplexer ausgestattete AUC. Da sehr groBe und sehr kleine Teilchen gleichzeitig in einem einzigen Zentrifugenlauf bestimmt werden, kennen wir nicht mehr wie zuvor eine konstante Rotorgeschwindigkeit N anwenden, sondern miissen diese mit Hilfe eines Geschwindigkeitsprogramms N(t) innerhalb einer Stunde von 0 auf 40000 U/min erhehen.
    Notes: The particle size distribution (PSD) of extremely broad distributed dispersions (diameter range 20 〈 D 〈 2000 nm) is not possible to be measured by analytical ultracentrifuge (AUC) using the standard technique, i.e. measuring turbidity τ at a single concentration c, because the specific turbidity τ/c varies too much between very small and very large particles. To solve this problem we have developed a new AUC technique, the so-called Coupling-PSD-Technique. Here two different concentrations of the same dispersion are measured simultaneously by one single AUC run with two corresponding curves of light intensity I vs. time t being registered. At a low standard concentration cs, mainly the larger particles are detected, while at a concentration ch 5 to 30 times higher mainly the smaller particles are registered. Both I(t)-curves are coupled mathematically and transformed into the requested broad distribution curve employing Stokes' law and Mie's light scattering theory for homogeneous isotropic spheres.We use an AUC together with an 8-cells-rotor and a multiplexer. Because very large and very small particles are to be measured simultaneously in one single run, we can no more apply a constant rotor speed N as before, but by means of a time program N(t) we always have to increase the rotor speed from 0 to 40000 rpm within one hour.
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  • 44
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    Angewandte Makromolekulare Chemie 162 (1988), S. 135-148 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die chemische Modifizierung von Polyvinylchlorid (PVC) durch ein Amin verleiht dem Polymeren höhere Reaktivität gegenüber der Pfropfcopolymerisation mit einem Vinylmonomeren. Die Pfropfcopolymerisation von Methylmethacrylat auf mit n-Butylamin modifiziertes PVC wurde thermisch mit Benzoylperoxid (Bz2O2) als Initiator oder photoaktiviert mit Benzophenon (BP) als Photosensibilisator gestartet. Das aus bestimmten Experimenten erhaltene rohe Polymerprodukt wurde durch fraktionierte Fällung in die verschiedenen Bestandteile wie Polymethylmethacrylat (PMMA, Homopolymeres), PVC-g-PMMA (Pfropfcopolymeres) und unverändertes (aminiertes) PVC aufgespalten. Die getrennten Fraktionen wurden mit Hilfe der IR-Spektroskopie und der Thermogravimetrie charakterisiert. Der Mechanismus der Pfropfcopolymerisation von den beiden verschiedenen Systemen wurde erörtert. In beiden Fällen wurden Pfropfausbeuten um 30 - 70%* und Pfropfcopolymerzusammensetzungen, PMMA/PVC (w/w) zwischen 2 und 3 erhalten.
    Notes: Chemical modification of poly(vinyl chloride), PVC, by an amine renders the polymer more reactive towards graft copolymerization with a vinyl monomer. The graft copolymerization of methyl methacrylate (MMA) on PVC modified by treatment with n-butylamine (n-BA) was started thermally at 30° using benzoyl peroxide (Bz2O2) as initiator and under photoactivation at 40° using benzophenone (BP) as photo sensitizer. The gross polymer products from selected experiments were fractionally separated into the constituent polymeric entities viz., poly(methyl methacrylate), PMMA (homopolymer), PVC-g-PMMA (graft copolymer), and unreacted (aminated) PVC following a method of fractional precipitation. The separated fractions were characterized by IR spectroscopy and thermogravimetry. The mechanisms of graft copolymerization for the two different systems have been discussed. In each case, grafting efficiencies of the order of 30-70% and graft copolymers having compositions given as PMMA/PVC (w/w) equal to 2-3 were readily obtained.
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  • 45
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    Angewandte Makromolekulare Chemie 162 (1988), S. 193-201 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Reihe oberflächensulfonierter, makroporöser Styrol-Divinylbenzol-Copolymerer mit unterschiedlichen Gehalten an SO3H-Gruppen wurden hergestellt. Sowohl von diesen Copolymeren als auch vom nichtsulfonierten Copolymeren wurden Porenstruktur, Oberflächenhydrophilie und -polarität sowie das Sorptionsverhalten gegenüber einigen in Blut vorkommenden Substanzen bestimmt. Der Sorptionsgrad wird umso kleiner, je größer die Oberflächenpolarität ist. Die teilsulfonierten Polymeren könnten eine Anwendung in der Hämoperfusion finden.
    Notes: A series of surface sulphonated macroporous styrene-divinylbenzene (S-DVB) copolymers containing various amounts of  - SO3H groups was obtained. Porous structure, surface hydrophilicity and polarity, and sorption properties of these copolymers as well as those of starting S-DVB resin towards some substances which are present in blood were determined. The sorption degree becomes the smaller the higher is the surface polarity. The partially sulphonated copolymers may find an application in hemoperfusion.
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  • 46
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß einer chemischen Behandlung von dünnen Filmen einer Composit-Membran aus sulfoniertem Polyphenylenoxid wurde untersucht. Über den Einfluß der Konzentration von wáßrigen Lösungen von Formaldehyd, Schwefelsäure, Salzsäure, Phosporsäure, Natriumhydroxid sowie der Behandlungsdauer auf die Trenncharakteristik der inversen Osmose der Composit-Membranen mit einer Ionenaus-tauschkapazität von 2,14 und 2,50 meq/g in verschiedenen Kombinationen wird ausführlich berichtet. Die Ergebnisse zeigen, daß unter den besten chemischen Behandlungsbedingungen eine Erhöhung der Trenncharakteristik der inversen Osmose der sulfonierten Polyphenylenoxid/Polysulfon-Composit-Membran erreicht wird.
    Notes: The effect of chemical treatment on the reverse osmosis (RO) separation characteristics of sulfonated poly(phenylene oxide) (SPPO) thin film composite membranes was investigated. The effects of the concentrations of aqueous solutions of formaldehyde, sulfuric acid, hydrochloric acid, phosphoric acid, sodium hydroxide, and treatment time on the RO separation characteristics of the composite membranes with ion exchange capacity (IEC) of 2.14 and 2.50 meq/g in various combinations are reported in detail. The results indicate some enhancement in RO separation characteristics of the SPPO/polysulfone (PS) composite membrane under the best conditions of the chemical treatment.
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  • 47
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Bei der Herstellung dünner Filme von sulfonierten Polyphenylenoxid/Polysulfon (SPPO/PS)-Composit-Membranen wurde untersucht, daß ein Zusatz von Nitromethan zu einer Lösung von sulfoniertem Polyphenylenoxidnatrium erhöhte Wirkung auf die Trenncharakteristik der inversen Osmose besitzt. Der Einfluß von gamma-Strahlung auf dünne Filme der Composit-Membran unter nassen und trockenen Bedingungen wurde ebenfalls untersucht. Um die maximal mögliche Verbesserung zu erreichen, wurden die Composit-Membranen einer kombinierten chemischen und Gammastrahlen-Behandlung unter nassen und trockenen Bedingungen unterworfen.Die experimentellen Ergebnisse dieser kombinierten Behandlung zeigen, dalß die SPPO/PS Composit-Membran dabei abgebaut wird.
    Notes: The enhancement effect of the addition of nitromethane into the coating solution of sulfonated sodium poly(phenylene oxide) (SPPONa) polymer for the synthesis of sulfonated poly(phenylene oxide)/polysulfone (SPPO/PS) thin film composite membranes on reverse osmosis (RO) separation characteristic was studied. The effect of gamma-ray irradiation on the SPPO/PS thin film composite membranes was also evaluated when the membrane samples were in the wet and dry conditions. The composite membranes were also subjected to a chemical treatment combined with gamma-ray irradiation in both wet and dry conditions in the hope of obtaining the maximum possible enhancement under each treatment. However, the experimental data of this combined treatment indicated the possibility of some degradation of the SPPO/PS composite membranes.
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  • 48
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    Angewandte Makromolekulare Chemie 163 (1988), S. 37-45 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Mischungen aus Poly(styrol-co-butadien)/Polybutadien, Naturkautschuk/Poly-(ethylen-co-propylen-co-dien und Naturkautschuk/Poly(butadien-co-acrylnitril)) wurden nach drei unterschiedlichen Verfahren compoundiert und Härtungsverhalten sowie Zugfestigkeit und Bruchdehnung der Vulkanisate wurden verglichen.
    Notes: Compounding of styrene-butadiene copolymer/polybutadiene, natural rubber/ethylene-propylene-diene terpolymer and natural rubber/butadiene-acrylonitrile copolymer blends was done in three different ways and their curing behaviour and the tensile properties of the vulcanizates are compared.
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  • 49
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Methylmethacrylat (MMA) wurde mit Hilfe von Cerammoniumnitrat als Initiator auf Stärke gepfropft. Die Pfropfcopolymeren wurden durch selektive Lösungsextraktion in einem Soxhlet-Extraktor isoliert. Der Einfluß von Reaktionszeit, Initiatorkonzentration, Temperatur sowie der Monomer- und Särekonzentration auf die Pfropfausbeute wurde untersucht. Eine erste Studie der Kinetik dieser Pfropfcopolymerisationsreaktion zeigt, daß sie dem üblichen kinetischen Verhalten einer Radikalpolymerisation folgt.
    Notes: Methyl methacrylate (MMA) was grafted onto starch using ceric ammonium nitrate as initiator. The graft copolymers were isolated by selective solvent extraction in a Soxhlet apparatus. The effects of reaction time, initiator concentration, temperature, monomer, and acid concentrations on the graft yields were investigated. A preliminary kinetic study of the graft copolymerisation reactions shows that they follow the conventional kinetic behaviour of free radical polymerisation.
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  • 50
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    Angewandte Makromolekulare Chemie 163 (1988), S. 47-61 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch Verwendung von Phenol-Formaldehyd-Harz mit gepreßten Olivenkenen im Gewichtsverháltnis 20/80 wurden kleine zylindrische Formkörper durch Härtung hergestellt. Diese wurden pyrolysiert und einige Proben mit Wasserdampf aktiviert. Für diese Formkörper und für zwei kommerzielle Aktivkohlen für Laboratoriumsbzw. Industrie-Anwendungen wurden folgende Eigenschaften bestimmt: die spezifische Oberfláche, die Struktur, die Adsorptionseigenschaften sowie die Adsorptionskapazität. Die Ergebnisse zeigen, daß die hergestellten kohlenstoffhaltigen Materialien durch Aktivierung höhere Werte für die untersuchten Eigenschaften ergeben als die nur pyrolysierten Proben und die zwei kommerziellen Aktivkohlen. Es wurde festgestellt, daß die Adsorption des 4-Nitrophenols für alle untersuchten kohlenstoffhaltigen Materialien gemäß der Freundlich-Gleichung stattfindet. Die Raster-Elektronenmikroskopie zeigt, daß die hergestellten kohlenstoffhaltigen Materialien andere Porenarten aufweisen als die kommerziellen Aktivkohlen. Die experimentellen Ergebnisse werden durch die molekularen Dimensionen der zur Adsorption verwendeten Substanzen und den Polarisationseffekt der Substituenten am Benzolring erklärt.
    Notes: Mixtures of phenol-formaldehyde-resin and pressed olive stones in a weight ratio of 20/80 were cured as small cylinders and then pyrolyzed. Some samples were also activated by steam. For these specimens and for two commercial activated carbons of laboratory or industrial uses the specific surface area, the structure, the adsorption properties, and the adsorption capacity were determined. The results indicate that the carbonaceous material produced by activation has greater values for the examined properties in comparison to the only pyrolyzed and the two commercial activated carbons, respectively. It was found that the Freundlich-equation is valid for the adsorption of 4-nitrophenol on all carbonaceous materials examined. The produced carbonaceous materials have different kinds of pores than the commercial activated carbons. The experimental results are explained with regard to the molecular dimensions of the adsorptive substances and the polarization effect of the substituents of the benzene ring.
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  • 51
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    Angewandte Makromolekulare Chemie 163 (1988), S. 101-114 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch Anwendung der nichtlinearen Programmiermethode basierend auf der mittleren harmonischen Näherung wurden aus den Kontaktwinkeldaten die freie Dispersions- und polare, freie Oberflächenenergie, γSVd und γSVp, sowie die kritische, freie Oberflächenenergie, γc, von Polymeren bestimmt. Die Komponenten der freien Oberflächenergie der zu untersuchenden Flüssigkeiten, γLVd und γLVp, die die Bedingungen für den maximalen Wechselwirkungsparameter, Φ, wiedergeben, wurden ebenfalls mit Hilfe dieser Methode bestimmt.
    Notes: The dispersion and polar surface free energy components, γSVd and γSVp, and the critical surface free energy, γc, of polymers were determined from contact angle data by the application of a nonlinear programming method using harmonic mean approximation.The surface free energy components of the probe liquids, γLVd and γLVp, which reflect the conditions of the maximized interaction parameter, Φ, were also simultaneously determined by this method.
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  • 52
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    Angewandte Makromolekulare Chemie 153 (1987), S. 113-124 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Käufliche Weizenmehlstärke wurde unter Verwendung verschiedener Mengen Schwefelkohlenstoff und Acrylnitril xanthogeniert und cyanethyliert und dann zur Herstellung von modifizierten Stärke-Naturkautschuk-Masterbatches eingesetzt. Weiterhin wurden die Einflüsse untersucht, die die Gleichgewichte der Xanthogenierung und Cyanethylierung gegenseitig aufeinander ausüben. Die Ergebnisse werden auf der Basis definierter Wechselwirkungen zwischen der Xanthogenatgruppe und dem freien Acrylnitril erklärt. Hierbei führen sowohl sterische Faktoren als auch die höhere Elektrophilie des Acrylnitrils zum Zerfall der Xanthogenatgruppe. Daher kann die Cyanethylierung nur noch in einem geringeren Ausmaß erfolgen.
    Notes: Common wheat flour starch was subjected to xanthation followed by cyanoethylation at various levels of carbon disulfide and acrylonitrile to prepare modified starchnatural rubber masterbatches. Mutual influences of the extents of equilibrium xanthation and cyanoethylation on each other have been studied. The results have been explained on the basis of a definite interaction between xanthate group and free acrylonitrile in which both the steric factors and higher electrophilicity of acrylonitrile lead to the decomposition of xanthate groups and reduced the extent of cyanoethylation.
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  • 53
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Aus Polychloropren und Polyvinylchlorid wurden Blends in verschiedenen Zusammensetzungen hergestellt und ihre Eigenschaften bestimmt. Die Eigenschaften der Blends zeigen, daß sie Polychloropren in vielen Anwendungen ersetzen können.
    Notes: Blends of polychloroprene rubber and plasticized polyvinylchloride have been prepared in various compositions and their properties evaluated. The properties of the blends show that they can be used to replace polychloroprene in many applications.
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  • 54
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The present paper describes a rheo-optical apparatus consisting of an elongational rheometer (with rotary clamps) and a device to measure birefringence. This equipment was designed to perform homogeneous deformations on polymer melts in the simple elongational mode. Elongational experiments were performed on polyisobutylene samples at room temperature using different strain rates (from \documentclass{article}\pagestyle{empty}\begin{document}$\dot \varepsilon$\end{document} 0.01 s-1 to 1 s-1). In typical experiments homogeneous elongations up to λ ≈ 200 and stresses up to 2 · 106 Pa were achieved. The stress, the birefringence, and the deformation were obtained by measuring the force, the sample thickness, the optical retardation (the frequency of the sampling was 20 Hz) and the width of the sample (the frequency of the sampling was 3 Hz). It was found that the stress-optical coefficient was constant. The homogeneity of the deformations was carefully controlled because inhomogeneities cause serious errors in the measurements of elongational viscosity and birefringence.
    Notes: Es wird über eine rheo-optische Apparatur zur Verstreckung von Polymerschmelzen mit rotierenden Klemmen berichtet, die mit einer Doppelbrechungs-Meßeinrichtung ausgerüstet ist. Mit dieser Einrichtung können einfache Dehnungen an Polymerschmelzen bis zu hohen Verstreckgraden unter homogenen Bedingungen durchgeführt werden. Während des Deformationsvorganges können die Spannung, die Doppelbrechung und die Probendicke mit einer Meßrate von 20 Hz, sowie die Probenbreite mit ca. 3 Hz erfaßt werden.Wir haben Messungen an Polyisobutylen bei Raumtemperatur mit verschiedenen Dehngeschwindigkeiten (0,01 s-1 〈 \documentclass{article}\pagestyle{empty}\begin{document}$\dot \varepsilon$\end{document} 〈 1 s-1) bis zu einem Verstreckgrad von λ ≈ 200 durchgeführt. Dabei wurden Spannungen bis zu 2 · 106 Pa erhalten. Das spannungsoptische Gesetz war bei homogener Versuchsführung stets erfüllt. Es wird gezeigt, daß ohne Kontrolle der Dehngeschwindigkeit und insbesondere bei inhomogener Dehung nicht nur Abweichungen vom spannungsoptischen Gesetz, sondern auch große Fehler bei der Spannungs- bzw. Viskositätsberechnung auftreten. Deshalb wurde großer Wert auf die Prüfung der Homogenität der Dehnung gelegt.
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  • 55
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    Angewandte Makromolekulare Chemie 153 (1987), S. 187-195 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The miscibility of various polymethylmethacrylate (PMMA)/polybutylmethacrylate (PBMA)/poly(methylmethacrylate-co-butylmethacrylate)systems has been studied. PMMA and PBMA are immiscible. Methacrylic homopolymers and copolymers are immiscible, too. A one-phase mixture from PMMA and PBMA is only accessible by copolymerization.
    Notes: Die Mischbarkeit von verschiedenen Systemen aus Polymethylmethacrylat (PMMA), Polybutylmethacrylat (PBMA) und Poly(methylmethacrylat-co-butylmethacrylat) (P(MMA-co-BMA)) wurde untersucht. PMMA und PBMA sind miteinander nicht mischbar. Die untersuchten Homopolymeren und entsprechende Methacrylatcopolymere bilden ebenfalls heterogene Systeme. Einphasige Mischungen aus PMMA und PBMA sind nur über Copolymerisation erreichbar.
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  • 56
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    Angewandte Makromolekulare Chemie 163 (1988), S. 169-193 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The condensation reaction of bisphenol A, melamine, and formaldehyde was investigated by gel permeation chromatography, 13C-NMR-spectroscopy, IR-spectroscopy and elemental analysis. Because of the high reaction rates the condensation could be investigated only in the range of pH 6-10. At pH 6 and 7 the reaction of melamine with formaldehyde is dominating.With increasing pH-value the condensation of bisphenol A with formaldehyde is observed preferably. At pH 10 the condensation results in high molecular products. Cocondensation of melamine and bisphenol A through methylene bridges does not take place. But as a separation of the bisphenol A-formaldehyde condensates from the other condensation products was not possible, the three components may be connected through methylene-ether groups and/or intermolecular hydrogen bridges.
    Notes: Die gemeinsame Kondensation von Bisphenol A, Melamin und Formaldehyd wurde mit Hilfe der Gelpermeationschromatographie, der 13C-NMR-Spektroskopie, IR-Spektroskopie und Elementaranalyse untersucht. Wegen der hohen Kondensationsgeschwindigkeit verläuft die Reaktion in Gegenwart der drei Komponenten nur im Bereich von pH 6-10 kontrollierbar. Bei pH 6 und 7 überwigt die Kondensation zwischen Melamin und Formaldehyd. Mit steigendem pH-Wert tritt die Reaktion von Bisphenol A mit Formaldehyd in den Vordergrund und führt bei pH 10 zu hochmolekularen Kondensationsprodukten.Auf direkte Cokondensation hinweisende Methylenverknüpfungen zwischen der phenolischen Komponente und Melamin konnten nicht nachgewiesen werden. Die Kondensationsprodukte des Melamins bzw. des Bisphenol A mit Formaldehyd lassen sich aber nicht mehr vollständig aus den Reaktionsgemischen der Vorkondensation abtrennen, was dafür spricht, daß die Komponenten über Methylenetherbrücken und/oder intermolekularen Wasserstoffbrücken miteinander verknüpft sind.
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  • 57
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Mit Hilfe der 13C-NMR-Spektroskopie wurde die Entwicklung der Oligomerenverteilung während der Polymerisation von 13C-angereichertem Ethylen mit dem löslichen Ziegler-Katalysatorsystem Cp2TiMeCl/AlMe2Cl verfolgt. Zuordnung und quantitative Auswertung aller Signale der verschiedenen wachsenden Ketten werden beschrieben. Die Geschwindigkeiten der Ethylen- und der Cp2 TiMeCl-Abnahme sowie die Bildungsgeschwindigkeit neuer Ketten konnten direkt aus den Spektren ermittelt werden. So läßt sich zum ersten Mal zeigen, daß die Konzentration der Ti-Propyl-und Ti-Pentylspezies in einen stationthen Zustand einlaufen. Dies ermbglicht, die Geschwindigkeitskonstanten der Ethyleninsertion in die Ti-Kohlenstoffbindung von Ti-Me, Ti-Pr und Ti-Pe zu ermitteln. Diese Ergebnisse fiihren zu einem detaillierten Ein-blick in den Ablauf der ersten Insertionsschritte und sind so eine Grundlage fur die mathematische Modellierung. Sie sind aufierdem ein weiterer unabhlngiger Beweis für die Giiltigkeit des dynamischen Modells des Mechanismus der Ethylenpolymerisation mit lbslichen Ziegler-Katalysatoren, nlmlich die Bildung der polymerisationsaktiven Spezies in zwei aufeinanderfolgenden sehr dynamischen Gleichgewichtsreaktionen.
    Notes: The development of the oligomer distribution during the polymerization of 13C-enriched ethylene by the soluble Ziegler catalyst system Cp2 TiMeCl/AlMe2Cl was followed by 13C-NMR spectroscopy. The assignment of the signals from the growing chains is described in full. It is shown that the rate of consumption of ethylene and Cp2 TiMeCl and the rate of formation of new chains can be monitored directly from the spectra. The concentrations of Ti-propyl and Ti-pentyl species during the polymerization were followed spectroscopically; both attain a steady state concentration. The relative rates were determined for the insertion of ethylene in the Ti-carbon bond of Ti-Me, Ti-Pr and Ti-Pe. These results give a detailed insight into the way that the oligomer distribution develops and provide a basis for its computer simulation. They also provide an independent proof that the dynamic model for the mechanism of ethylene polymerization with soluble Ziegler catalysts of the type Cp2 TiRCl/AlRnClm is correct.
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  • 58
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    Angewandte Makromolekulare Chemie 154 (1987), S. 99-110 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß verschiedener Reaktionsbedingungen auf die Bromierung von ataktischem Poly(propylen) (APP) in Tetrachlorkohlenstofflösung wurde untersucht. Mit zunehmender Reaktionszeit steigt der Bromierungsgrad. Auch mit steigender Verdünnung der APP-Lösung nimmt die Bromierungsgeschwindigkeit zu, welche bezüglich der APP-Konzentration die Ordnung 0,66 hat. Dies wird erklärt durch die anfängliche Substitution eines Wasserstoffs am tertiären Kohlenstoffatom. Die folgende H-Abstraktion an den benachbaren sekundären und primären Kohlenstoffatomen ist erleichtert. Die scheinbare Aktivierungsenergie wurde zu 11,9 kcal/mol bestimmt. Die Bromierungsgeschwindigkeit steigt bis zu einem APP : Br2-Molverhältnis von 1 : 1 an, darüber hinaus wird die Geschwindigkeit unabhängig vom Molverhältnis. Die Bromierung scheint folgendermaßen zu verlaufen: Nach anfänglicher Substitution eines tertiären H-Atoms durch freie Bromradikale werden nach und nach auchdie sekundäen und primären H-Atome durch weitergehende Substitution oder durch Addition nach einem Eliminierungsschritt ersetzt. Das IR-Spektrum bestätigt die Anwesenheit von Brom in den Proben.
    Notes: Effects of various reaction conditions on bromination of atactic poly(propylene) (APP) in carbon tetrachloride solution were studied. It was found that with the increase of the reaction time the extent of bromination increases. Also with an increased dilution of APP the rate of bromination increased following a bromination order of 0.66 with respect to APP concentration. This has been ascribed to initial replacement of the hydrogen at the tertiary carbon atoms followed by enhanced ease of abstraction from the neighbouring secondary and primary carbon atoms. The apparent activation energy was found to be 11.9 kcal/mol. The rate of bromination increases with an increase of the APP: Br2 molar ratio up to 1 : 1, beyond which the rate becomes independent of this ratio. Mechanism of bromination appears to be an initial substitution of tertiary H-atoms by bromine radicals followed subsequently by replacement of secondary and primary H-atoms via either progressive substitution or elimination-addition. IR spectra confirm the presence of bromine in the samples.
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  • 59
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    Angewandte Makromolekulare Chemie 163 (1988), S. 205-207 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Cyclodextrin membrane-modified electrodes as sensor materials have been prepared by dipping platinum electrodes in the water suspensions of an oriented cyclodextrin polymer, followed by drying the polymer layers on the electrodes. The polymer is obtained by the solid-liquid reaction between the crystal of cyclodextrin inclusion complex and hexamethylene diisocyanate in anisole. The thickness (2 - 80 μm) of the cyclodextrin membrane is satisfactorily controlled by changing the concentration of the water suspension of the polymer. The cyclodextrin membranemodified electrodes show a significant response to p-nitrophenolate in water which is highly in contrast with no measurable response to o- and m-nitrophenolates.
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  • 60
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In this part properties and efficiency of the developed model1,2 are discussed. A variation of the parameters shows that vigorous effects are caused by the effective aggregation. All calculations show that at low conversion there are little temporal steps between the sequential aggregation steps. In the range of 5% to 20% conversion the velocity of aggregation decreases and the aggregative stability agrees with experiences given in the literature. It is shown that the calculated results are in agreement with the experimental results and therefore the presented model is a suitable possibility to describe the formation of some PVC-morphology properties.
    Notes: In der vorliegenden Arbeit werden die Eigenschaften des früher1,2 entwickelten Modells untersucht und diskutiert. Die Variation der Modellparameter zeigt einen großen Einfluß der Aggregationsprozesse auf die Subkornmorphologie. Bei niedrigen Monomerumsätzen ist das Zeitintervall zwischen zwei aufeinanderfolgenden Aggregationsschritten sehr klein, so daß für das Teilchenwachstum die Geschwindigkeit der Aggregation der Unterstrukturen entscheidend ist. Im Bereich zwischen 5% und 20% Monomerumsatz sinkt die Aggregationsgeschwindigkeit sehr stark, so daß für das Teilchenwachstum zunehmend die Polymerisationsreaktion an Bedeutung gewinnt. Aggregative Stabilität wird nach dem Modell für einen Teilchengrößenbereich erhalten, der sich in Übereinstimmung mit experimentellen Daten aus der Fachliteratur befindet. Die berechneten Teilchengrößen entsprechen ebenfalls den in der Literatur publizierten experimentellen Werten, so daß das Modell eine gute Grundlage für die Beschreibung einiger morphologisch bestimmter Polymereigenschaften bildet.
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  • 61
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    Angewandte Makromolekulare Chemie 165 (1989), S. 21-34 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurden unidirektionale Verbundwerkstoffe aus Novolakharz mit Kohlenstoff-Fasern gemäß der Prepreg-Methode verarbeitet. Das Novolakharz wurde durch Polymerisation von Phenol mit Formaldehyd (Mol-Verhältnis 1 : 0,82) und Oxalsäure als Katalysator (1,5 Gew.-% von Phenol) hergestellt. Die Härtung des Novolakharzes wurde mit Hexamethylentetramin (Hexa) durchgeführt, während das geeignete Verhältnis durch die IR-Spektroskopie bestimmt wurde.Es wurden Proben aus Novolak/Hexa (Gew.-Verhältnis 14: 1), verstärkt mit kommerziellen Kohlenstoff-Fasern, unter verschiedenen Bedingungen (z. B. verschiedene thermische Programme und verschiedene Verhältnisse von Novolakharz : Kohlenstoff-Fasern) hergestellt. Die mechanischen Eigenschaften der hergestellten Proben (wie Biegefestigkeit, Zugfestigkeit, usw.) wurden bestimmt, und ihre Struktur wurde mit Hilfe der Elektronenmikroskopie untersucht.Mit zunehmendem Volumenverhältnis der Kohlenstoff-Fasern werden nicht nur alle mechanischen Eigenschaften des verstärkten Materials verbessert, sondern auch sein Nutzungsgrad nimmt zu, und die Herstellungsbedingungen üben einen größeren Einfluß aus. Die mit dem gleichen Verhältnis von Kohlenstoff-Fasern (z. B. 15 Vol.-%) hergestellten Proben weisen mit zunehmendem Härtungsgrad des Novolaks verbesserte mechanische Eigenschaften auf. Der Häirtungsgrad des Novolaks während der Anfangsphase (Gel-Zeit) als auch während der Endphase (Nachhärtung) kann mit Hilfe der IR-Spektren des härtenden Novolaks verfolgt werden, während der Härtungsgrad der Zwischenphase nur indirekt aus den Werten der mechanischen Eigenschaften der entsprechenden Proben bestimmt werden kann.Aus der Korrelation zwischen den Herstellungsparametern und den mechanischen Eigenschaften der Proben ergeben sich optimale Bedingungen für die Verarbeitung in der Wärmepresse zur Herstellung von mit Kohlenstoff-Fasern verstärkten Novolakharzen (1. Phase: T1 = 125-145°C, t1 = 20 min - 1 h, ohne Druck; 2. Phase: T2 = 180-195°C, t2 = 40 min, P2 ≃ 1,5 kN /cm2).
    Notes: Unidirectional composite materials of novolac resin with carbon fibers were fabricated according to the prepreg method. Novolac resin was prepared by polymerization of phenol with formaldehyde (mole ratio 1 : 0.82) in the presence of oxalic acid as catalyst (1.5 wt.-% to phenol). The curing of novolac resin was performed with hexamethylenetetramine (hexa), while the appropriate proportion was determined by using the IR-spectroscopy.Specimens of novolac/hexa (weight ratio 14:1) reinforced with carbon fibers commercially available were fabricated under different conditions (e.g. different thermal programs and different proportions of novolac/carbon fibers). The mechanical properties of the fabricated specimens (like flexural strength, tensile strength, etc.) were determined and their structure was examined by scanning electron microscopy.By increasing the volume proportion of carbon fibers, not only all mechanical properties of the composite material were increased, but also their degree of utilization was increased and also the production conditions had greater influence. Concerning the specimens produced by the same proportion of carbon fibers (e.g. 15 vol.-%) their mechanical properties were improved by increasing the curing of novolac. The degree of curing of novolac during the initial phase (gel time) and during the ultimate phase (post-curing) can be followed with the aid of IR-spectra of the cured resin, while the degree of curing for the intermediate phase can be obtained only indirectly from the values of the mechanical properties of the corresponding specimens.From the correlation between the production parameters and the mechanical properties of the samples the optimal conditions for processing of the thermopress for the manufacture of carbon fiber reinforced novolac were concluded (1. phase: T1 = 125-145°C, t1 = 20 min - 1 h, without pressure; 2. phase: T2 = 180-195°C, t2 = 40 min, P2 ≃ 1,5 kN/cm2).
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  • 62
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    Angewandte Makromolekulare Chemie 165 (1989), S. 69-78 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In dieser Arbeit interessieren wir uns für den Einfluß von Konzentration und Temperatur auf den elektrischen Widerstand eines Butyl-Kautschuks (IIR), der mit zwei Typen von Ruß (Hoch-Abrasion-Schmelzofen-Ruß (HAF) und Schnell-Extrusion-Hochofen-Ruß (FEF)) versetzt ist. Ergebnis war, daß die Leitfähigkeit bei niedrigem Rußgehalt hauptsächlich durch thermische Aktivierung der Ladungsträger erreicht wird. Bei mittleren Konzentrationen überwiegt der Tunnel-Mechanismus bei niedriger Temperatur, gefolgt von der thermischen Aktivierung bei relativ hoher Temperatur. Dies gilt für beide Rußarten. Das metallartige Verhalten bei Gemischen mit hoher Rußkonzentration kann sowohl der thermischen Ausdehnung der Tunnelwege zwischen Kohlenstoff-Agglomeraten als auch dem Zusammenbruch der Kohlenstoff-Agglomerate bei steigender Temperatur zugeschrieben werden.
    Notes: In this study we are interested in the effect of concentration and temperature on the electrical resistivity of butyl rubber (IIR) loaded with two types of carbon black, (namely, high abrasion furnace black (HAF), and fast extrusion furnace black (FEF)). It was found that the conductivity at low carbon black concentrations is mainly achieved by thermal activation of carriers. Tunneling mechanism at low termperature followed by thermal activation at relatively high temperature is found to be predominant for moderate concentrations for both carbon blacks. The metal-like behaviour which was observed in highly loaded compounds was attributed to both, the thermal expansion of the tunneling paths between carbon-carbon agglomerates and the breakdown of carbon agglomerates with temperature.
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  • 63
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    Angewandte Makromolekulare Chemie 165 (1989), S. 79-87 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Arbeit beschreibt die Synthese von Halogenderivaten des Phenylglycidylethers und die Möglichkeiten der Verwendung von diesen Komponenten als Flammverzögerer und reaktive Verdünnungsmittel für Epoxidharze.Mit Hilfe der Nelder-Mead-Simplexmethode wurden die besten Reaktionsbedingungen gefunden. Die so hergestellten Produkte zeichnen sich durch eine hohe Qualität aus und wurden mit einem niedermolekularen Epoxidharz gemischt und mit Diaminodiphenylmethan gehärtet.Die Viskosität von Harzgemischen und die Brennbarkeit der gehärteten Systeme wurden untersucht. Mit dem erhöhten Gehalt an Halogen (Chlor oder Brom) steigt die Viskosität, und die Brennbarkeit der Epoxide wird reduziert.
    Notes: This study deals with the synthesis of halogenated derivatives of phenyl glycidyl ether and with possibilities of their use as flame retardants and reactive diluents of epoxy resin.The best reaction conditions optimized by Nelder-Mead simplex method were found. The products of very high quality were prepared. They were mixed with a lowmolecular epoxy resin and cured by diamino diphenyl methane.The viscosity of the resin mixtures and limiting oxygen index of cured systems were determined. It was found that a higher content of halogen, both chlorine and bromine, causes increasing viscosity and reduced flammability of the epoxides.
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  • 64
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Durch Messungen von Tg, Tm und Tc (Trübungspunkt) wurden Phasendiagramme der vier verträglichen Polymermischungen von chlorierten isotaktischen Polypropylenen (Chlorgehalt 39,2 (CPP-40) und 49,8 Gew.-% (CPP-50)) mit Poly(ethylen-co-vinylacetat)en (Vinylacetatgehalt 40 (EVA-40) und 45 Gew.-% (EVA-45)) untersucht. Von den vier Mischungspaaren war die Mischung von CPP-50 mit EVA-40 am besten verträglich.
    Notes: By measuring Tg, Tm and Tc (cloud point) phase diagrams for the four miscible blends of chlorinated isotactic polypropylenes (chlorine content 39.2 (CPP-40) and 49.8 wt.-% (CP-50)) with Poly(ethylene-co-vinyl acetate)s (vinyl acetate contents 40 (EVA-40) and 45 wt.-% (EVA-45)) were investigated. The blend of CPP-50 with EVA-40 was the most compatible of the four blend pairs.
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  • 65
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Synthese und Charakterisierung von Kationenaustauschmembranen aus PE-PS-DVB-Interpolymeren für die Elektrolyse von Borax-Lösung zur Erzeugung von Borsäure und Natronlauge wurden durchgeführt und mit den Eigenschaften von im Handel erhältlichen Membranen („Nafion 324“ und „Permaplex C-20“) verglichen.
    Notes: The synthesis and the characterization of the PE-PS-DVB interpolymer cationexchange membranes in the electrolysis of borax solutions to produce boric acid and sodium hydroxide simultaneously was carried out. The characterization of the teflon based “Nafion 324” and polystyrene-DVB based “Permaplex C-20” membranes was also performed in the same system for comparison.The DVB contents were varied between 3 - 12% (by wt. in total monomers) and the increase of the cross-links resulted in the decrease of the water contents and ionexchange capacities of the membranes. The PE present in the membrane acted as a barrier for electroosmotic water transport. The membranes with high DVB contents showed better electrolysis performance due to their low water contents and low electroosmotic water transport properties. The use of the interpolymer membrane containing 11.6% DVB resulted in high current efficiency and high sodium cation dynamic transport number and worked satisfactorily at the process conditions of borax electrolysis.
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  • 66
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    Angewandte Makromolekulare Chemie 165 (1989), S. 125-131 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Aus Rizinusöl und difunktionellen Säuren, wie Oxal-, Malon-, Bernstein-, Glutar-, Adipin-, Suberin- und Sebacinsäure, wurden Prepolyester hergestellt. Diese Prepolyester (PPE) wurden anschließend mit Methylmethacrylat und 1% Ethylenglykoldimethacrylat als Vernetzer interpenetriert. Die Polymerisation wurde radikalisch mit Benzoylperoxid gestartet. Die neuen PPE/Polymethylmethacrylat (PMMA)-interpenetrierenden Netzwerke wurden als Pulver erhalten. Sie wurden durch ihr Löseverhalten, IR-Spektroskopie und ihr thermisches Verhalten charakterisiert.
    Notes: Prepolyesters were obtained from castor oil and dibasic acids, viz oxalic, malonic, succinic, glutaric, adipic, suberic and sebacic acid. These prepolyesters (PPE) were subsequently interpenetrated with methyl methacrylate containing 1% ethylene glycol dimethacrylate as crosslinker by radical polymerization initiated with benzoyl peroxide. The novel PPE poly(methyl methacrylate) PPE/PMMA interpenetrating polymer networks (IPNs) were obtained as powder. They were characterized by solubility behaviour, IR spectral study and thermal behaviour.
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  • 67
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: 2,4-Ionen, ein polymeres quartäres Ammoniumsalz, wurde auf einem makroporösen chlormethylierten Poly(Styrol-co-Divinylbenzol)-Harz (XAD-2) immobilisiert. Der Ionen-Gehalt des Harzes, der durch CHN-Elementaranalyse bestimmt wurde, betrug 50,2 g/kg Harz. Der wichtigste Nebeneffekt des modifizierten Harzes, das Ausbluten des Katalysators 2,4-Ionen, kann durch eine spektrophotometrische Methode, die extrem geringe Konzentraionen an freiem Ionen an der Oberfläche des Harzes messen kann, ermittelt werden.Die Aktivität der immobilisierten 2,4-Ionen/Kobalt(II)-phthalocyanin-tetranatriumsulfonat-Komplexe in bezug auf die oxidative Kupplung von Thiolen ist viel niedriger als im homogenen Fall, aber noch beträchtlich höher als im polymerfreien System. Die beobachtete Abnahme der Reaktionsgeschwindigkeit resultiert nicht aus Behinderungen des Massentransports, sondern vorzugsweise aus den Katalysatoreigenschaften wie z. B. einem sehr niedrigen N+/Co-VerhtUtnis. Die aktiven Zentren scheinen nur in der äußeren Hiille der Harzpartikel vorhanden zu sein.
    Notes: A poly(quaternary ammonium) salt, 2,4-ionene, has been immobilized on a macroporous chloromethylated poly(styrene-divinylbenzene) resin (XAD-2). The ionene content of the resin, determined by CHN elemental analysis, was 50.2 g/kg resin. The most important side effect of the modified resin, catalyst (2,4-ionene) bleeding, can be detected by a spectrophotometric method capable of determining extremely low concentrations of free ionene in the supernatant of the resin.The activity of these immobilized 2,4-ionene/cobalt(II)phthalocyanine-tetrasodiumsulfonate (CoTSPc) complexes towards the oxidative coupling of thiols is much lower than in the homogeneous case, but still considerably higher than for the polymer free system. The observed decrease in reaction rate does not originate from the considerable mass transfer resistances but predominantly from catalyst properties like a very low local N+/Co ratio. The active sites appear to be present in the outer shell of the resin particles only.
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  • 68
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Röntgendiffraktometrische Untersuchungen und DSC-Messungen an Blend-Filmen, die aus Lösungen von PEEK und PES hergestellt wurden, zeigen eine Phasenseparation bei den Filmen, die bei 340°C hergestellt wurden. Das Kristallisationsverhalten von Filmen, die bei 340°C hergestellt, anschließend abgeschreckt und bei 180°C getempert wurden, ist identisch mit dem von PEEK. Filme, die bei 300°C hergestellt wurden, kristallisierten erst durch Tempern bei 250°C. Blockcopolymere, die aus Oligomeren von PEEK und PES erhalten wurden, unterscheiden sich in dieser Hinsicht von Blends der gleichen Zusammensetzung. Die Glastemperatur von Copolymeren mit einem PEEK-Gehalt von mehr als 50% liegt höher als die von PEEK selbst, während der Schmelzpunkt dieser Copolymeren niedriger als der von PEEK ist.
    Notes: Polymer blends of PEEK with PES were prepared by the solution blending method. Copolymers composed of PEEK and PES components were synthesized from these oligomers. The formation conditions exerted an influence over the molecular aggregation and the crystallization behaviors of the blend films and block copolymers which were examined by X-ray diffractometry and DSC analysis. As a result, phase-separation in the blend films was found when the formation temperature was high. The blend films formed at 340°C, quenched and annealed at 180°C, exhibited the same crystallization behavior as those of PEEK. In the case of the blend films formed at 300°C, the annealing of the films at 250°C was required to crystallize the blend films. The Tg of a copolymer with a PEEK component content of more than 50% tends to shift toward a higher temperature than the Tg of PEEK itself, and the Tm of the copolymer toward a lower temperature than that of PEEK ist.
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  • 69
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Im Zusammenhang mit dem Studium des Wirkungsmechanismus von industriell hergestellten Antidegradantien vom Typus der N-Phenyl-N′-sek-alkyl-1,Cphenylendiamine wurde die Reaktion von N-Phenyl-1,4-benzochinonimin (I) und 4-Hydroxydiphenylamin (II) mit dem Kohlenstoff-Radikal 1-Cyano-l-methylethyl (R·) studiert. Das Gemisch von I und II reagiert mit R· sehr leicht unter Bildung der Verbindungen III, VI und VIII. I allein reagiert wesentlich langsamer, und das Reaktionsgemisch enthält mehrere Produkte. Neben der Verbindung III wurden auch die Verbindungen IV und VII identifiziert. II allein reagiert bei denselben Bedingungen nicht. Die Verbindung IV bildet die zwei isomeren Strukturen syn und anti. Die Verbindung VIII ist ziemlich unbeständig; aus ihren Umwandlungsprodukten wurde XI isoliert. Bei der Reduktion von IV entsteht die Verbindung V, die ähnlich wie VIII unbeständig ist.
    Notes: The reaction of N-phenyl-1,4-benzoquinoneimine (I)Decoding of abbreviations see p. 103/104. and 4-hydroxydiphenylamine (II) with the carbon centred 1-cyano-1-methylethyl radical (R·) was studied in connection with an investigation of the action mechanism of industrial antidegradants, such as N-phenyl-N′-sec-alkyl-1,4-phenylenediamines. The mixture of I and II reacts very readily with R·, giving rise to III, VI, and VIII. I alone reacts much slowlier, and the reaction mixture contains more products. IV and VII were identified along with III. Under the conditions used, II alone does not react at all. IV exists in two isomeric forms, syn and anti. VIII is very labile; XI was isolated from its transformation products. Reduction of IV gives V, which is labile, similarly to VIII.
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  • 70
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    Angewandte Makromolekulare Chemie 156 (1988), S. 123-137 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Samples of polyoxymethylene (unstabilized and stabilized with the antiozonants N-isopropyl-N′-phenyl-p-phenylenediamin (IPPD) and bis-(1,2,3,6-tetrahydrobenzaldehyd)pentaerithritylacetal (Vulkazon AFS)) were ozonized under mechanical load in a special climate chamber. Surface damages were determined by IR-spectroscopy and scanning electron microscopy. During the ozonolysis a damaged layer is formed, the thickness of which increases with increasing time of ozonization. During this damaging reaction acetal groups are attacked and oligomers are formed.
    Notes: Proben von unstabilisiertem und mit den Antiozonantien N-Isopropyl-N′-phenyl-p-phenylendiamin (IPPD) und Bis-(1,2,3,6-tetrahydrobenzaldehyd)-pentaerithrityl-acetal (Vulkazon AFS) stabilisiertem Polyoxymethylen wurden unter mechanischer Belastung in einer Klimakammer ozonisiert. Die Schädigungen auf der Oberfläche wurden IR-spektroskopisch und rasterelektronenmikroskopisch untersucht. Während der Ozonisierung von POM bildet sich eine geschädigte Schicht, deren Dicke mit zunehmender Ozonisierungszeit wächst. Hierbei wird das Polymere an den Acetalbindungen angegriffen, wodurch Ketten gespalten werden und Oligomere entstehen.
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    Angewandte Makromolekulare Chemie 156 (1988), S. 105-121 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Mit Hilfe verschiedener Methoden wurde der Einfluß der Entfernung unterschiedlicher porenbildender Verdünner aus porösen Styrol-Ethylstyrol-Acrylnitril-Divinylbenzol-Copolymeren auf die Netzwerkstruktur untersucht. Der günstigste Weg, den ursprünglichen strukturellen Bau des porösen Netzwerkes zu bewahren, welches in Gegenwart von solvatisierenden Verdünnern erhalten wurde, ist das Entfernen des inerten Mediums mit Methanol. Wenn die Wasserdampfmethode angewendet wird, fin det der sog. Kollapseffekt statt, und die aus solchen Harzen hergestellten Anionenaustauscher adsorbieren weniger Farbstoff im Vergleich zu jenen, die aus Perlen hergestellt worden sind, die mit Methanol behandelt wurden; Grund hierfür ist die durch den Kollaps veränderte Porengröße. Es wurde ebenfalls festgestellt, daß die in Anwesenheit von solvatisierenden Verdünnern (Mischungen aus Quellungs- und Fällmitteln) hergestellten Copolymeren in Methanol sehr gut quellen, obwohl dieses ein Fällungsmittel für Polystyrol ist.
    Notes: The influence of the removal of various diluents, pore forming agents from the porous styrene-ethylstyrene-acrylonitrile-divinylbenzene copolymers on the structure of the matrix was investigated by several methods. The most advantageous pathway to preserve the initial structural edifice of the porous networks performed in the presence of solvating diluents consisted in the removal of the inert media with methanol as it was noticed from the experimental data. If the steam treatment is applied, the collapse effect takes place and the anion exchangers prepared from such matrices exchange/adsorb less dye stuff by comparison with ones formed from beads treated with methanol, because the pore size was changed. It was also noticed that the porous copolymers performed in the presence of the solvating diluents (mixtures of solvatings and precipitants) swell very well in methanol though it is a precipitating medium for the polystyrenic macromolecular chains.
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    Angewandte Makromolekulare Chemie 156 (1988), S. 139-149 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: An Styrol-Zinkacrylat-Copolymeren wurde die Abhängigkeit der Glasübergangstemperatur von der Aufheizgeschwindigkeit und der Zusammensetzung mit Hilfe der Differential-Scanning-Calorimetrie untersucht. Die Thermogravimetrie wurde benutzt, um die Pyrolyse dieser Copolymeren an Luft bei drei verschiedenen Aufheizge-schwindigkeiten zu untersuchen. Die thermische Zersetzung von Ionomeren ist ein 3-Stufen-Prozeß. Die Reaktionsordnung und Aktivierungsenergie wurde für jede Stufe der Zersetzung bestimmt unter Verwendung eines Computerprogramms, das auf den Methoden von Kissinger, Freeman-Carrol und Ozawa basiert. Es zeigte sich, daß die thermische Stabilität durch die ionischen Gruppen abnimmt.
    Notes: The dependence of glass temperature on the heating rate and the composition for styrene-zinc acrylate copolymers has been investigated by differential scanning calorimetry. Thermogravimetry was used in order to examine these copolymers undergoing pyrolysis in an atmosphere of air at three different heating rates. Thermal decomposition of ionomers is a three-stage process. The orders and activation energies have been determined for each stage of decomposition using the computer programs based on the methods of Kissinger, Freeman-Carrol, and Ozawa. It was found that the heat stability is lowered by the ionic groups.
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  • 73
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    Angewandte Makromolekulare Chemie 156 (1988), S. 151-162 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Pfropfung der hydrophilen Monomeren N-Vinylpyrrolidon, 2-Hydroxyethyl-methacrylat und Acrylamid auf ungesättigte segmentierte Polyurethane in N,N-Dimethylformamid mit 2,2′-Azobisisobutyronitril als Initiator wurde untersucht. Die Pfropfcopolymeren wurden von den Homopolymeren durch selektive Extraktion in Soxhlet-Apparaturen abgetrennt. Die kinetische Untersuchung der Pfropfcopolymerisation zeigte, daß die Reaktionen dem gewöhnlichen kinetischen Verhalten radikalischer Polymerisationen folgen. Die Abhängigkeiten der Pfropfungsgeschwindigkeit von der Initiator- und N-Vinylpyrrolidonkonzentration waren von 0,5 bzw. 1,0 Ordnung. Für 2-Hydroxyethylmethacrylat wurden sie zu jeweils 0,5 und 2,0 gefunden. Die Gesamtaktivierungsenergie der Pfropfcopolymerisation des 2-Hydroxyethylmethacrylats und des N-Vinylpyrrolidons betragen jeweilig 21,81 und 16,28 kJ/mol.
    Notes: Grafting of unsaturated segmented polyurethanes with some hydrophilic monomers such as N-vinyl pyrrolidone, 2-hydroxyethylmethacrylate and acrylamide in N,N-dimethylformamide have been studied using 2,2′-azobisisobutyronitrile (AIBN) as initiator. Graft copolymers were isolated from homopolymers by selected solvent extraction using a Soxhlet apparatus. A kinetic study of graft copolymerization reactions showed that the reactions follow the conventional kinetic behaviour of free radical polymerization. The dependencies of the grafting rate on initiator and N-vinyl pyrrolidone concentrations were of 0.5 and 1.00 order, respectively. However, for the 2-hydroxyethylmethacrylate, the dependencies of the grafting rate on initiator and monomer concentrations were found to be of 0.5 and 2.00 order, respectively. The overall activation energy for the graft copolymerization of the 2-hydroxyethylmethacrylate and N-vinyl pyrrolidone were 21.81 kJ/mol and 16.28 kJ/mol, respectively.
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  • 74
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    Angewandte Makromolekulare Chemie 156 (1988), S. 179-185 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Ultra fine particles were impregnated by using a finely porous cellulose gel membrane. The impregnated gel membrane is a green transparent one and looks like a solid solution. Highly dispersed Ni catalysts on carbon were obtained from thermal decomposition of these gel membranes. The particle size is in the range of several nm to a few ten nm. They show interesting catalytic properties for hydrogenation of olefins such as cyclooctadiene.
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  • 75
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The thermo-oxidation resistance and weatherability of LDPE and HDPE compositions, containing up to 45 wt.% calcium carbonate, are investigated. The thermo-oxidation resistance is investigated by dynamic DTA and natural ageing is carried out in an exposure station in a seaside climate. The change in strength and colour after ageing is determined. The behaviours of filled and unfilled polymers are compared. Empirical equations are given, describing the change in the investigated parameters during natural ageing.
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  • 76
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: An Proben aus Polypropylen, die bei sehr unterschiedlichen Einstellungen von Spritzgußmaschinen und Extrudern hergestellt wurden, stellten sich deutliche Abhängigkeiten des Alterungsverhaltens von den thermischen und mechanischen Produktionsparametern ein, die nicht durch unterschiedliche Schmelzetemperaturen bedingt sind. Insbesondere kann ausgesagt werden, daß bei Spritzguß eine hähere Scherbelastung und damit stärkere Orientierungen -eine stärkere Veränderung der Eigenspannungen hervorrufen-einen früheren Glanzabfall und-eine geringere Initialzeit bis zur Rißbildung bewirken.Bei Extrusion fiihrt eine geringere Abkühlgeschwindigkeit und damit ein gröberes Gefüge zu -einer stärkeren Veränderung der Eigenspannungen-einem friiheren und ausgeprägteren Glanzverlust-sowie zu einem früheren Abfall der Reißdehnungen.Unbekannt ist, -ob diese Wirkungen auch bei anderen Thermoplasten als PP auftreten-ob sie auch bei stabilisierten Systemen in relativ gleichem Umfange auftreten-und ob es sich lohnt, die beobachteten Effekte ggf. durch ge zielte Maschineneinstellungen auszunutzen.Auf jeden Fall sollten auf diesem Gebiet weitere Arbeiten durchge-führt werden.
    Notes: Specimens of unmodified polypropylene have been manufactured using extreme adjustings of injection moulding machines and extruders. After artificial weathering, distinct relations of ageing processes to thermal and mechanical production parameters were found, which are not influenced by different melting temperatures. It can be started in particular, that during injection moulding a larger shear stress (resulting in more distinct orientation) results in -a greater change in residual stresses-an earlier gloss reduction-a shorter initial period before cracking.During extrusion a lower cooling rate (resulting in a coarser structure) leads to -a greater change in residual stresses-an earlier and more distinct gloss reduction-an earlier loss of ultimate strain.It remains unknown, whether -these relationships will be similar with other thermoplastic materials than PP-these relationships appear to the same relative extend with stabilized systems-it may be advantageous, to use the observed effects by adjusting the injection moulding and extrusion machines in a special way.It seems to be significant to do more research work in this field.
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  • 77
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    Angewandte Makromolekulare Chemie 160 (1988), S. 1-15 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(tetramethylenadipat)diol mit einer Molmasse von 2000 wurde bei Temperaturen von 60 und 80°C in Gegenwart von Wasser bzw. 1,4-Butandiol sowie den gebräuchlichsten PUR-Katalysatoren (Dabco und Dibutylzinndilaurat) gelagert und die Solvolyse untersucht. Die Geschwindigkeit der Solvolyse nimmt mit steigender Temperatur deutlich zu. Die Alkoholyse wird durch Dibutylzinndilaurat weitaus stärker katalysiert als durch 1,4-Diazabicyclo[2.2.2]oktan. Die Hydrolyse verläuft langsamer, da vermutlich die Katalysatoren bei diesem Prozeß desaktiviert werden. Die mechanischen Eigenschaften von Polyurethanen, die mit den partiell abgebauten Diolen hergestellt wurden, korrelieren gut mit der Abnahme der Molmasse.
    Notes: Poly(tetramethylene adipate)diol having a molar mass of 2000 was stored at temperatures of 60 and 80°C in the presence of water or 1,4-butanediol and a common PUR-catalyst like 1,4-diazabicyclo [2.2.2]octane (DABCO) or dibutyltindilaurate (DBTL) and the solvolysis was investigated. The rate of solvolysis is low at 60°C except for DBTL and shows a drastic increase at 80°C. In the alcoholysis reaction DBTL is a much more active catalyst than DABCO. The rate of hydrolysis is slower probably because the catalysts are deactivated by the acidic products formed in this process. The mechanical properties of polyurethanes made from the degraded polyols are in good correlation with the decrease in molar mass.
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    Angewandte Makromolekulare Chemie 160 (1988), S. 17-28 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß der Zugabe von Bis(allylphenyl) Typ (TM 120)-Monomeren auf die Eigenschaften von unidirektional mit Carbonfasern verstärkten 4,4′-Bismaleimidodiphenylmethan (BM) - 2,4-Tolylendiamin (A) (1:0,3 Molverhältnis) (BM-A)-Verbundkörpern wird vorgestellt. Das Aushärteverhalten sowie das thermische Verhalten in Luft wurde mit Hilfe der Differentialkalorimetrie (DSC) und der Thermogravimetrie (TGA) untersucht. Die thermische Stabilität nimmt mit ansteigenden Konzentrationen von TM 120 deutlich zu. Demgegenüber steht ein Anstieg der Biegefesigkeit, der interlaminaren Scherfestigkeit sowie der Schlagzähigkeit mit zunehmender Monomerkonzentration. Optimale mechanische Eigenschaften wurden bei etwa 20 Tle./100 Tle. TM 120 erreicht.
    Notes: The paper deals with the effect of addition of bis(allylphenyl) type (TM 120) monomer on the properties of unidirectionally carbon fibre reinforced 4,4′ bismaleimidodi-phenyl methane (BM) - 2,4-tolylene diamine (A) (1:0.3 molar ratio) (BM-A) composites. The curing and thermal behaviour of the blends was investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) in air atmosphere. A marginal decrease in thermal stability was observed with increasing concentration of TM 120. Flexural, interlaminar, and impact strength of the laminates increased in the presence of this monomer. Optimum mechanical properties were observed at ∼ 20 phr of TM 120.
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  • 79
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In dieser Arbeit wurden Veränderungen des verschweisßten Rohr- und Fittingmaterials (isotaktisches Polypropylen Homo- bzw. Copolymer PP-R grau pigmentiert) wührend der für die Praxis relevanten Innendruckversuche untersucht.Bei der technischen Verschweißung von Polyolefinen entstehen charakteristische Gefüigezonen im Schweißnahtbereich, welche vom Fßgematerial und den Fngebedingungen beeinflußt werden. In der vorliegenden Untersuchung wurden sowohl die Materialcbergange im Fiigebereich (mit den Methoden - schichtenweise Differentialkalorimetrie, Polarisations- bzw. Elektronenmikroskopie sowie Fluoreszenzspektroskopie mit extrem hoher Ortsauflösung) als auch die Eigenspannungen hinsichtlich ihrer Verlnderung bei Langzeitpriifung im Innendruckzeitstandversuch bei 95°C bis zu einer Prüfzeit von 18.100h untersucht.Die Abbauvorgänge der Makromoleküle bei der Langzeitprüfung der 364 untersuchten Schweißmuster werden in einer gesonderten Arbeit behandelt (1).Durch die Innendruckversuche bei 950 C findet eine Nachkristallisation und eine Gefügevergrijberung sowohl in der Schweißnaht als auch im Gefüge der Schweißpartner statt. Dabei werden die beim Schweißvorgang eingebrachten Orientierungen und Eigenspannungen unter dem Einfluß von Wärme beim Innendruckversuch weitgehend abgebaut. Durch die unter Druckeinwirkung einsetzenden Flieävorgange jedoch werden neue Eigenspannungen eingebracht.Es konnte gezeigt werden, daß bei guter Verschweißung von PP mit PPCO ein kontinuierlicher Übergang (Mischungsbereich) vom Homopolymeren zum Copolymeren auftritt, der auch beim Langzeiteinsatz im Innendruckversuch erhalten bleibt.
    Notes: The present study deals with changes of welded material of pipes and fittings (isotactic polypropylene homo and copolymer PP-R grey pigmented) during the standardized internal pressure tests, which are commonly used for these products.Technical welding of polyolefines causes characteristic structures, which depend on the natural of the welded material and the welding conditions.In this investigation both the transition of material in the welding seam and the changes of internal stresses during internal pressure tests at 95°C until 18.100h test time were examined. The methods we used were Differential calorimetry of think layers, Polarization- and Electron microscopy, Fluorescence spectroscopy with extreme high local resolution.The effects of decomposition of the macromolecules in the welded samples during the internal pressure tests will be described in a separate paper (1).The internal pressure tests at 95O C cause a recrystallization and an increase of the particle size in the structure of the welding seam and in the structure of the welded parts themselves. Under the above described testing conditions the orientations and internal stresses initiated by the welding procedure will relaxe influenced by heat. However the creep effects that occur in the material when exposed to pressure introduce new internal stresses. It could be shown that in perfectly welded parts a continuous transition from PP to PPCO occurs, which did not change after long time application of internal pressure tests.
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  • 80
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    Angewandte Makromolekulare Chemie 168 (1989), S. 129-134 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Das Reaktionsprodukt eines Cyclohexanon-Formaldehyd-Harzes mit dem Säurechlorid des Radikalinitiators 4,4′-Azo-bis(4-cyanopentansäure) wurde als Initiator für die Styrolpolymerisation eingesetzt, um ein Cyclohexanon-Formaldehyd-Harz/Polystyrol-Copolymeres zu bilden. Das Copolymere zeigte ähnliche Löslichkeit wie Polystyrol.
    Notes: The reaction product of cyclohexanone-formaldehyde resin with an acid chloride of a radical initiator, 4,4′-azo-bis(4-cyano pentanoic acid) was used as initiator for styrene polymerization to form a cyclohexanone-formaldehyde resin/polystyrene copolymer. The copolymer showed similar solubility as polystyrene.
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  • 81
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    Angewandte Makromolekulare Chemie 168 (1989), S. 145-155 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Entgegengesetzte Ladungen wurden durch tertiäre Amin- und Carboxylgruppen in Polyurethan (PU) und Polystyrol (PS) eingeführt, um durch gemeinsame Massepolymerisation ein interpenetrierendes PU/PS Polymernetzwerk (IPN) zu erhalten. Vier IPNs wurden hergestellt: ein Voll-IPN, zwei Semi-IPNs und ein lineares Blend. Die Wirkung der geladenen Gruppen auf die mechanischen Eigenschaften und die Morphologie der vier Polymermischungen wurde untersucht.Es wurde gefunden, daß PU/PS IPNs mit geladenen Gruppen keine Phasenseparation und somit homogene Verteilung aufweisen, was durch elektronenmikroskopische (SEM) Aufnahmen nachgewiesen wurde. Dynamisch-mechanische Messungen zeigen, daß die Übergangspeaks des Verlust-Moduls E″ in die Mitte zwischen den beiden Übergangspeaks der beiden Komponenten ohne geladene Gruppen liegen. Dies ist von der Zunahme des Gehaltes an geladenen Gruppen abhängig. Gleichzeitig nimmt der Speichermodul E′ in einer Stufe ab, was im Gegensatz zu der zweistufigen Abnahme bei Proben ohne Ladungsträger steht.Die Zugfestigkeit nimmt in allen vier Polymermischungen mit der Zunahme an Acrylsäure (AA) in Poly(Styrol-Acrylsäue) PSAA zu, was in dem PU/PSAA Voll-IPN besonders deutlich wird.
    Notes: Opposite charges, namely tertiary amine and carboxyl groups, were introduced into polyurethane (PU) and polystyrene (PS), respectively, to prepare PU/PS interpenetrating polymer networks (IPNs) by means of simultaneous bulk polymerization. Four IPNs were synthesized: a full-IPN, two semi-IPNs and a linear blend. The effect of charge groups on the mechanical properties and morphology of the four polymer alloys was investigated.It is found that the PU/PS IPN which was incorporated with charge groups is free of any phase-separation, and sufficiently uniformly distributed, as can be seen from the corresponding scanning electron microscopy (SEM) photographs. Dynamic mechanical analysis indicates that the transition peak of the loss modulus E″ will move towards the centre between the two transition peaks of both components in the absence of charge groups, as a function of an increase in the contents of the opposite charge groups. Meanwhile the storage modulus E′ will decrease in a single-stage way from the previous two-stage mode.The tensile strength in all the four polymer alloys increased markedly along with an increase in the contents of acrylic acid (AA) in the poly(styrene-acrylic acid) (PSAA), which clearly can be seen for the PU/PSAA full-IPN.
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  • 82
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    Angewandte Makromolekulare Chemie 168 (1989), S. 157-168 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Pyrolysis behaviour and coke characteristics of different precursors for carbon processing: thermosetting resins (resol, novolak), hydrolytic lignin, pitch, tar as well as their blends were studied using differential thermal analysis (DTA) and X-ray diffraction techniques. The blends novolak-pitch, resol-tar and resol-hydrolytic lignin show a higher coke yield after carbonisation up to 1000°C compared to the corresponding individual substances. A good correlation between the integral procedural decomposition temperature T*A of the investigated precursors and their coke yield is found.
    Notes: Mittels Thermo- und Röntgenstrukturanalyse wird eine vergleichende Untersuchung des Pyrolysevorganges und der Mikrostruktur des aus zwei Gruppen organischer Bindemittel und deren Mischungen gewonnenen Koksrückstandes durchgeführt. Gruppe I umfaßt reine und mit Hydrolyselignin gefüllte Resol- und Novolak-Phenol-Formaldehydharze und Gruppe II Steinkohlenpech und -teer. Es wird festgestellt, daß sich die Mischungen Novolakharz-Pech, Resolharz-Teer und Resolharz-Hydrolyselignin beim Erhitzen nicht wie mechanische Gemische verhalten und eine erhöhte Ausbeute an Koksrückstand liefern. Weiterhin wird gefunden, daß die integrale Endtemperatur der Pyrolyse (T*A) dieser Substanzen als quantitatives Maß für die Ausbeute an Koksrückstand im Anschluß an die Carbonisierung der Proben dienen kann.
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  • 83
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    Angewandte Makromolekulare Chemie 168 (1989), S. 217-223 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The paper describes the successful synthesis of silicon containing bismaleimide resin 4,4′-carbo(4,4′-bismaleimido phenoxy)diphenyl silane. The char yield of the bismaleimide resin in N2 atmosphere was found to be 55% at 800°C. Chain extension of bismaleimide with 4,4′-diamino diphenyl sulfone reduced the char yield and thermal stability.
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  • 84
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    Angewandte Makromolekulare Chemie 160 (1988), S. 67-81 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurden neue Coordinationspolymere mit Schiffschen Basen aus Terephthalal dehyd und S-Benzyldithiocarbazol als Liganden in DMF-Lösung hergestellt. Die erhaltenen Coordinationspolymeren wurden durch Elementaranalyse, magnetische Suszeptibilität, elektronische und IR-Spektroskopie charakterisiert. Die durch Thermogravimetrie bestimmte thermische Stabilität der Coordinationspolymeren nahm in der folgenden Reihenfolge ab: \documentclass{article}\pagestyle{empty}\begin{document}${\rm Zn} \simeq {\rm Fe} 〉 {\rm Co} 〉 {\rm Ni} 〉 {\rm Min} \simeq {\rm Cu}$\end{document} Mn(II)-, Fe(II)-, Co(II)- und Ni(II)-Coordinationspolymere haben eine Oktaederstruktur mit der Koordinationszahl6, während bei den Cu(II)- und Zn(II)-Coordinationspolymeren eine 4-fach koordinierte quadratisch-planare bzw. eine tetraedrische Struktur gefunden wurde. Ligandenfeld- und nephelawetische Parameter wurden aus den Spektren errechnet. Dam wurde die Ligandenfeldtheorie spin-erlaubter Übergänge angewandt, die sich als konsistent mit einer 6-fach koordinierten Struktur für Mn(II)-, Fe(II)-, Co(II)- und Ni(II)-Coordinationspolymere erwies. Die Elementaranalysen ergaben bei allen Coordinationspolymeren ein Ligand: Metall-Verhältnis von 1 : 1 und deuteten bei den Mn(II)-, Fe(II)-, Co(II)- und Ni(II)-Coordinationspolymeren auf am Zentralatom assoziierte Wassermoleküle hin.
    Notes: New Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) coordination polymers of Schiff base ligand derived from terephthalaldehyde and S-benzyldithiocarbazate have been synthesized in DMF media. The coordination polymers have been characterized by their elemental analysis, magnetic susceptibility, and by electronic and infrared spectral measurements.The thermal stability of each polymer was found out by thermogravimetric analysis. The thermal stability of coordination polymers obtained from thermograms has the following order: \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm Zn} \simeq {\rm Fe} 〉 {\rm Co} 〉 {\rm Ni} 〉 {\rm Min} \simeq {\rm Cu}$\end{document} Mn(II), Fe(II), Co(II), and Ni(II) coordination polymers are of a six-coordinated octahedral structure while Cu(II) and Zn(II) coordination polymers are found to be four-coordinated square planar and tetrahedral structure, respectively. The ligand-field and nephelauxetic parameters have been determined from the spectra, using ligand-field theory of spin-allowed transitions which are found consistent with six-coordinate structure for Mn(II), Fe(II), Co(II), and Ni(II) coordination polymers. Elemental analyses indicates a ligand: metal ratio of 1 : 1 in all the coordination polymers and the association of water molecules with central metal atom in case of Mn(II), Fe(II), Co(II), and Ni(II) coordination polymers.
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  • 85
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    Angewandte Makromolekulare Chemie 160 (1988), S. 91-106 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Emulsionen von aromatischen Polyamidsären (PMPE and PBPPM) in DMF und Methanol wurden benutzt, um gleichmäßige Filme auf Leiteroberflächen durch Elektrophorese abzuscheiden. Die Ausbeute und Qualität der abgeschiedenen Filme hängen von der Art der Polyamidsäre, dem Lösemittel, dem Fällungsmittel, dem oberflächenaktiven Mittel, dem pH-Wert und dem Polymergehalt ab. Die Bedingungen zum Erreichen der höchsten Abscheidungsausbeuten wurden bestimmt.
    Notes: The emulsions of aromatic polyamic acids (PMPE and PBPPM) in DMF and methanol were used to coat uniform films on conductor surfaces by electrodeposition. The deposition yield and quality of the deposited films are dependent on sort of polyamic acid, solvent (DMF), precipitant (MeOH), surfactant (TEA), pH value and solid content. To get maximum deposition yields from PMPE and PBPPM, the best conditions of electrodeposition were required as follows: pH value 5.7 and 5.58, MeOH/DMF weight ratio 3.0 and 2.8, solid content 3.5 and 2.4 wt.-%. Deposition yield was found to obey Faraday's law of electrolysis, and the higher the equivalent weight of the polyamic acid, the higher the coulombic yield.
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  • 86
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    Angewandte Makromolekulare Chemie 160 (1988), S. 107-115 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein einfaches Modell von Doppelassoziaten wurde verwendet, um die Doppelschichtsorption von binären Gasgemischen an flexiblen linearen Polymerketten zu beschreiben. Die Isothermengleichung nach diesem Modell ist ein einfaches Produkt der isothermen Gleichung, die die Doppelschichtadsorption von binären Gasgemischen an einer homogenen festen Oberfläche beschreibt und einer Funktion, die die spezifischen Merkmale der Sorption an Polymeren widerspiegelt.
    Notes: A simple model of double associates is used to represent bilayer sorption of binary gas mixtures on a flexible linear chain of a polymer. The isotherm equation derived in terms of this model is a simple product of the isotherm equation describing bilayer adsorption of binary gas mixtures on a homogeneous solid surface and a function reflecting specific features of sorption on polymers.
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  • 87
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    Angewandte Makromolekulare Chemie 160 (1988), S. 131-140 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: For a polymer system sulfur-styrene containing 10 wt.-% styrene the morphologie depending on the polymerization temperature and time is described. Besides the characteristical orthorhombic phase a monoclinic and a pseudoorthorhombic phase were detected. Moreover amorphous material exists, depending on the polymerisation parameters.
    Notes: Für ein Polymersystem Schwefel-Styrol mit 10% Styrol wird die Abhängigkeit der Morphologie von der Polymerisationstemperatur und -zeit beschrieben. Neben der charakteristischen orthorhombischen Phase wurden röntgenographisch eine monokline und eine pseudoorthorhombische Phase nachgewiesen. Außerdem liegt, abhängig von den Polymerisationsparametern, ein amorpher Anteil vor.
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  • 88
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    Angewandte Makromolekulare Chemie 160 (1988), S. 117-129 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Für eine anionische Polymerisation mit langsamer Start- und schneller Wachstumsreaktion wurde ein analytischer Ausdruck entwickelt, der es erlaubt, mittlere Molekulargewichte und Molekulargewichtsverteilungen von Polymeren vorauszuberechnen, die in einem halbkontinuierlichen Polymerisationsverfahren bei Zulauf einer verunreinigten Monomerlösung zu einer vorgelegten Initiatolösung entstehen. Die Gültig keit des Modells wurde an der Polymerisation von Isopren mit n-Butyllithium in n-Heptan überprüft. Die beobachteten Unterschiede zwischen theoretischen und experimentellen Werten werden auf die Änderungen in den Geschwindigkeitskonstanten von Start- und Wachstumsreaktion zurückgeführt, die dadurch hervorgerufen werden, daß sich die Polarität der Lösung durch die Anreicherung mit polaren Verbindungen ändert. Weiterhin wird gezeigt, daß bimodale Molekulargewichtsverteilungen entstehen, wenn sich an die halbkontinuierliche Verfahrensweise eine diskontinuierliche zur Erhöhung des Monomerumsatzes anschließt.
    Notes: For anionic polymerization with slow initiation and rapid propagation step analytical expressions are presented to calculate average molecular weights and molecular weight distributions for a semi-batch process, in which a monomer solution contaminated by impurities is fed to an initiator solution in the reactor. The validity of the model was checked for the case of the polymerization of isoprene by n-butyllithium in n-heptane. The differences observed between theoretical and experimental values are explained by the changes in the rate constants of the initiation and the propagation step caused by the change in the polarity of the reaction solution by the continuously fed impurities. Furthermore it is shown that polymers with bimodal molecular weight distributions are formed if the semi-batch procedure is followed by a batch one to increase the monomer conversion.
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  • 89
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    Angewandte Makromolekulare Chemie 160 (1988), S. 141-154 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Wärmehärtungsmechanismus von zu Anstrichen verwendeten Polyethersulfonen wurde unter Verwendung von FTIR/PAS und ESCA untersucht. Als Ergebnis wurde bestätigt, daß der Luftsauerstoff Einfluß auf den Wärmehärtungsmechanismus hat. Das heißt, die Härtung des Polyethersulfonfilms beginnt an der Oberfläche und verläuft entsprechend Reaktion (4) weiter.
    Notes: Thermosetting mechanism of paint-use polyethersulfones was studied by utilizing FTIR/PAS and ESCA. As a result, it was confirmed that the oxygen in the air has an effect on the thermosetting mechanism. That is, the polyethersulfone film were baked from the surface, and proceeded according to reaction (4).
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  • 90
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    Angewandte Makromolekulare Chemie 160 (1988), S. 155-162 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurde der Mechanismus der Reaktion von 4-Ethylphenol mit Zimtaldehyd mittels HET 2DJ 13C-NMR Spektroskopie, 1H-NMR Spektroskopie und GPC untersucht. In der ersten Stufe findet die Addition des 4-Ethylphenols an die Carbonylgruppe und an die Doppelbindung des Zimtaldehyds statt. In der zweiten Stufe reagiert die —CH(OH)-Gruppe mit 4-Ethylphenol und bildet verzweigte Produkte in rötlich gefärbten Harzen mit einem Durchschnittsmolekulargewicht on 600. Die Reaktion verläuft bei Temperaturen über 100°C in stark saurem Medium.
    Notes: The mechanisms of the reaction between 4-ethylphenol and cinnamaldehyde were studied by means of HET 2DJ 13C-NMR spectroscopy, 1H-NMR spectroscopy and GPC. In the first step of the reaction the addition of 4-ethylphenol to carbonyl group and to double bond of cinnamaldehyde takes place. In the second step of the reaction the —CH(OH)-group reacts with 4-ethylphenol to form branched products of red coloured resins with an average molecular weight of 600. The reaction takes place at temperatures above 100°C in strong acid medium.
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  • 91
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    Angewandte Makromolekulare Chemie 160 (1988), S. 163-173 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die elektrischen und paramagnetischen Eigenschaften des durch eine direkte Methode aus Benzol und Schwefel synthetisierten Poly(phenylensulfid)s wurden untersucht. Die Geichstromdunkelleitfähigkeit dieses Polymeren im nativen Zustand ist 10-10 S/m. Sie nimmt während des Dotierens mit Jod um 8 Größenordnungen zu. Es wurde für undotierte Proben n-Typ- und für die mit Jod dotierten Proben p-Typ-Leitfähigketi beobachtet. Anhand der ESR-Messungen wurden die Zahl der paramagnetischen Zentren und der g-Faktor bestimmt, die entsprechend gleich 0.80 · 1017 Spins/g und 2.0037 für das undotierte Polymere bei Raumtemperatur betragen. Änderungen der Spinkonzentration sowohl für die mit Jod dotierten als auch für die im Temperaturbereich von 513 - 903 K getemperten Proben werden dargestellt. Es wird versucht, die Form der ESR-Linien auf eine quantitative Weise zu diskutieren.
    Notes: Electrical and paramagnetic properties of poly(phenylene sulphide) synthesized by a direct method from benzene and sulphur were investigated. In darkness dc conductivity of the polymer in its pristine state is of the order 10-10 S/m. Upon doping with iodine it increases by 8 orders of magnitude. For undoped samples the n-type conductivity and for those doped with iodine the p-type conductivity was observed. On the basis of ESR experiments the number of spins and g-value were determined, which for undoped polymer at room temperature are equal to 0.80 · 1017 spins/g and 2.0037, respectively. Next, the changes in spin concentration both for the iodine doped samples and these annealed within the temperature range 513 - 903 K were described. An attempt to discuss the ESR lineshape in a quantitative way was also made.
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  • 92
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    Angewandte Makromolekulare Chemie 160 (1988), S. 175-186 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: 3-Carboxy-4-hydroxyacetophenon (CHAP) wurde in verschiedenen Mengenverhältnissen mit Formaldehyd unter Verwendung von Alkali als Katalysator polykondensiert. Die erhaltenen Polykondensate (CHAP-F) wurden durch Elementaranalyse, IR-Spektroskopie, Bestimmung des Zahlenmittels der Molmasse (M̄n), Thermogravimetrie und Bestimmung der Grenzviskosität charakterisiert. Es wurden polymere Metallchelate mit Cu2+ -, Fe3+ -, Co2+ -, Ni2+ - und UO2+2 -Ionen hergestellt und charakterisiert. Mit Hilfe der Batch-Austauschmethode wurden Ionenaustauschereigenschaften eines CHAP-F Harzes gegen Fe3+ - Cu2+ - und Ni2+ -Ionen bestimmt.
    Notes: 3-Carboxy-4-hydroxyacetophenone (CHAP) was polycondensed with various proportions of formaldehyde using alcoholic alkali as catalyst. The resin samples, designated as CHAP-F, have been characterized by elemental analyses and IR spectroscopy, by estimation of their number average molecular weights (M̄n), by measurement of intrinsic viscosity, and by TGA. Polymeric metal chelates of one CHAP-F sample with Cu2+, Fe3+, Co2+, Ni2+, and UO22+ ions have been prepared and characterized.Ion-exchanging properties of one CHAP-F resin sample for Fe3+, Cu2+, and Ni2+ metal ions are studied by the application of the batch-equilibration method.
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    Angewandte Makromolekulare Chemie 160 (1988), S. 187-192 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Reaktionsenthalpien für die Addition von Hydroxidanion an substituierte Phenylisocyanate wurden mit MNDO berechnet. Die erhaltenen Werte stimmen sehr gut mit den Reaktionsgeschwindigkeiten der Addition von 2-Ethylhexanol an Phenylisocyanate überein. Dies ermöglicht eine Abschätzung der Reaktionsgeschwindigkeiten für nucleophile Additionen innerhalb vernünftiger Grenzen, ohne daß experimentelle Arbeiten durchgeführt werden müssen.
    Notes: The enthalpies for the addition of hydroxide anion to substituted phenylisocyanates have been calculated with MNDO. The results obtained correlate well with the rates of addition of 2-ethylhexanol to phenylisocyanates. This allows us to estimate the rates for nucleophilic addition within reasonable limits without the need for experiments.
    Additional Material: 2 Ill.
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  • 94
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    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 160 (1988), S. 211-211 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 95
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: As hard blocks in polyether block amides, polyamides are used whose length is intensively regulated by dicarboxylic acids. Since, with regard to melting and crystallization behaviour, this acid constitutes an interfering structural unit in the chain, and in the case of a completely converted product each chain contains one acid molecule, it is essential to know where in the chain incorporation will occur. As opposed to monofunctional chain regulators which always form a chain end, a bifunctional chain regulator can a priori also be randomly incorporated into the inner part of the chain. This leads to a far greater interference than occurs if the chain regulator molecule and the chain end, which acts as an interfering unit in any case, coincide with each other.By means of adipic acid-regulated oligoamides based on lauryl lactam, the incorporation of the chain regulator was examined by NMR spectroscopy and compared with model calculations. This resulted in a close match only if it was presupposed that the incorporation was carried out randomly with the same degree of probability at any point whatsoever between two lauryl lactam structural units or at the chain end.Further calculations illustrate the effects of the incorporation of the chain regulator on the size of the amorphous portion.
    Notes: Als Hartblöcke in Polyetherblockamiden werden durch Dicarbonsäuren stark geregelte Polyamide eingesetzt. Da die Säure in Hinblick auf das Schmelz- und Kristallisationsverhalten einen Störbaustein in der Kette darstellt und bei einem ausgeregelten Produkt jede Kette ein Säuremolekül enthält, ist es von Bedeutung zu wissen, wo in der Kette der Einbau erfolgt. Anders als bei monofunktionellen Reglern, wo der Regler stets ein Kettenende bildet, kann ein bifunktioneller Regler a priori auch statistisch im Inneren der Kette eingebaut werden. Dies führt zu einer viel stärkeren Störung, als wenn das Reglermolekül und das sowieso als Störstelle wirkende Kettenende zusammenfallen. Anhand adipinsäuregeregelter Oligoamide auf Basis von Laurinlactam wird kernresonanzspektroskopisch der Einbau des Reglers untersucht und mit Rechnungen verglichen. Es ergibt sich nur dann gute Übereinstimmung, wenn vorausgesetzt wird, daß der Einbau statistisch erfolgt und dabei mit gleicher Wahrscheinlichkeit für jede beliebige Stelle zwischen zwei Laurinlactambausteinen oder am Kettenende abläuft. Weitere Rechnungen verdeutlichen den Einfluß des Reglereinbaus auf die Größe des amorphen Anteils.
    Additional Material: 6 Tab.
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  • 96
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Auf Grund von mikroskopischen Beobachtungen wurde festgestellt, daß unter dem Einfluß von UV-Strahlung die Oberfläche von PVC-Filmen einer Formveränderung unterliegt. Auf der Oberfläche erscheinen Bläschen und Löcher. Die sich absondernden Gasprodukte der Polymerfotodestruktion verursachen die Bildung dieser Bläschen und Löcher. Größere Oberflächenänderungen wurden in Filmen mit einem Zusatz von 1-5% eines MMA/MA-Copolymeren beobachtet. Das weist auf eine in diesem Modifikator stattfindende Photoabbaureaktion hin, deren Ergiebigkeit größer ist als in reinem PVC. Dieser Modifikator wird in PVC eingeführt, um die Filmoberfläche zu verbessern, beschleunigt allerdings ihre Zerstörung unter dem Einfluß von UV-Strahlung. Es wurde festgestellt, daß Cyclohexanonspuren in den Proben den Photoabbau von MMA/MA retardieren, diesen Prozeß in PVC aber beschleunigen.
    Notes: By means of microscopic observation, the deformation of the surface of PVC films caused by 253.7 nm UV radiation was investigated. Numerous blisters and holes were formed by the gaseous photodecomposition products of the polymer.More apparent deformation of the films containing MMA/MA suggests that the photodecomposition of this modifier occurs with higher efficiency than that of PVC.MMA/MA copolymer is introduced into PVC films to improve the smoothness of their surface, but this modifier accelerates the deformation of this surface under UV irradiation. It was also found that traces of cyclohexanone in samples retard the photodecomposition of MMA/MA and accelerate this process in PVC.
    Additional Material: 7 Ill.
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  • 97
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 170 (1989), S. 29-41 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Anzahl von Harzen wurde durch gemeinsame Kondensation von p-Aminoacetophenon (p-AAph), substituierten Benzoesäuren wie m-Tolylsäure (m-TA), o-Tolylsäure (o-TA), Phthalsäure (PhA), p-Nitrobenzoesäure (p-NBA), p-Chlorbenzoesäure (p-CIBA) und Formaldehyd (F) in Gegenwart von verschiedenen Säuren und Basen als Katalysatoren hergestellt. Die Harze wurden IR-spektroskopisch charakterisiert. Die Löslichkeitsparameter wurden gemäß Small's Gruppenbeteiligung berechnet; sie stimmen gut mit den experimentellen Werten überein. Das thermische Verhalten und die bakteriologischen Eigenschaften der Harze wurden auch untersucht.
    Notes: A number of resins has been prepared by condensing p-amino-acetophenone (p-AAph) with substituted benzoic acid such as m-toluic acid (m-TA), o-toluic acid (o-TA), phthalic acid (PhA), p-nitrobenzoic acid (p-NBA), p-chlorobenzoic acid (p-CIBA) and formaldehyde (F) in presence of some acids and bases as catalysts. The resins were characterized by infrared spectra of the characteristic groups. The solubility parameters were calculated from Small's group contribution which agreed well with the experimental values. The thermal behaviour and the bacteriological properties of the resins have also been investigated.
    Additional Material: 3 Ill.
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  • 98
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    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 175 (1990), S. 107-116 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zur Beschreibung der Polymerisationsgeschwindigkeit der radikalischen Fallungspolymerisation von Acrylsäure in Toluol wurde ein Modell entewickelt. Die experimentelle Überprüfung des Modells erfolgte durch Messungen in einem isotherm betriebenen Reaktionskalorimeter. Das Modell beschreibt die Polymerisationsgeschwindigkeit bis zum vollständigen Umsatz in einem Temperaturbereich von 40 bis 60°C.
    Notes: A kinetic model for the free-radical precipitation polymerization of acrylic acid in toluene was developed and verified experimentally by using an isothermal reaction calorimeter. The model predicts the rate of polymerization accurately up to complete conversion in the temperature range of 40 to 60°C.
    Additional Material: 3 Ill.
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  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 175 (1990), S. 157-168 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wird über Untersuchungen an Legierungen aus isotaktischem Polypropylen und EPDM-Elastomer berichtet, die mit hochenergetischen Elektronen bestrahlt worden waren. Die Mischungsverhältnisse in den Proben überstrichen sowohl den für elastomermodifizierte Thermoplaste typischen Bereich als auch den der thermoplasticschen Elastomeren. Eine Vernetzung der Komponenten über die Grenzfläche hinweg wurde nachgewiesen. Diese grenzflächenübergreifende Vernetzung bewirkte eine merkliche Verbesserung der mechanischen Eigenschaften insbesondere des thermoplastischen Elastomeren.
    Notes: Blends of isotactic polypropylene and EPDM rubber have been treated by electron irradiation in the composition range of rubber modification and in the thermoplastic rubber composition range as well. Mutual crosslinking of the components through the interface could be detected. This intercrosslinking caused a remarkable improvement of the mechanical properties particularly of the thermoplastic rubber.
    Additional Material: 4 Ill.
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  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 175 (1990), S. 205-205 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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