ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Physics  (479)
  • Wiley-Blackwell  (479)
  • Institute of Electrical and Electronics Engineers (IEEE)
  • Wiley
  • 1985-1989  (479)
  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 379-388 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pseudo first-order rate constants for the solvolytic displacement of benzyl bromide in 100% ethanol and in 80 and 60% aqueous ethanol (v/v) are reported. The effect of adding poly(ethylene glycol) (PEG) and PEG dithiols and diamines to the solvolytic solutions has been studied. The solvolytic rates are mildly retarded on adding PEG, MW 950, or PEG dimercaptoacetate, MW 548 or 748 (at a concentration of about 8% of the polymer) to reactions in absolute ethanol. In 80% ethanol, however, a rate acceleration by the polymers was observed, with the thiols exhibiting the largest effects. PEG di(3-mercaptopropionate) reacts slightly faster than the PEG dimercaptoacetates, but liberated acid affects the former's reaction. Three molecular weights of primary diamines structurally derived from propylene oxide-capped PEG were evaluated and found to increase solvolytic rates of benzyl bromide significantly. Kinetic evaluation and comparisons with reactions containing equivalent amine groups per gram in an appropriate model (ethanolamine) revealed that the polymer's amine groups are actively involved nucleophilically. Grunwald-Winstein plots and second-order rate constants revealed that the polymeric diamines caused the benzyl bromide to undergo polymer-assisted displacement in all solvent compositions. Since it was noted that the second-order rates increased as the PEG amine molecular weight increased, it appears that the PEG framework may be assisting the reaction.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1057-1061 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of poly(vinylidene fluoride) with several different bases in dimethylformamide solution yields dehydrofluorinated products with conjugated polyene structures. The extent of elimination can be controlled by varying the amount of added base. The structural properties of dehydrofluorinated materials depend on the base used. Polymer films cast from DMF solution exhibit electronic conductivity upon iodine doping; the conductivity is also a function of the base used.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1119-1124 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For calculating the ratio of the intrinsic viscosities of branched and linear polymers of the same molecular weight, [η]B/[η]L, a new theory taking into account the excluded volume effect is presented. By using the modified Flory equation, the excluded volume effect of branched polymers is predicted with the aid of the first-order perturbation theory. The linear expansion factor αs is converted to the hydrodynamic expansion factor αη by using the Kurata-Yamakawa theory. Our calculated results, i.e., [η]B/[η]L and 〈s2〉B/〈s2〉L, agree well with experiment for various type branched polymers, i.e., randomly branched and comb-shaped polymers of poly(vinyl acetate).
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1163-1173 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of crosslinked polydiacetylenes and its two-component interpenetrating polymer networks (IPNs) was carried out utilizing its polar and flexible substituent groups. Polydiacetylenes were crosslinked by the formation of allophanate linkages utilizing urethane groups in the substituent groups of the polydiacetylenes. Elemental analysis, DSC, TMA, solvent resistance, and IR spectra are presented as evidence for the formation of crosslinked polydiacetylenes. IPNs of polydiacetylenes and an epoxy resin (diglycidyl ether of bisphenol A) were synthesized by using simultaneous and sequential methods of synthesis. A study of phase morphology of the simultaneous and sequential IPNs was carried out using electron microscopy, TMA, and DSC.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1493-1503 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The final network structure of epoxy polymers cured with a crosslinking agent is strongly connected with the type and amount of the curing agent and conditions. Concerning the morphology of this network, it has been reported that cured epoxies are two-phase systems, containing roughly spherical floccules arranged in a matrix resembling the constituent phases. In this paper and by using an epoxy-polymer cured with different amounts (i.e., different than the stoichiometric one) of a curing agent, strong indications of their network-structure heterogeneity have been disclosed. For this study, two different experimental techniques, such as dynamic mechanical measurements and DSC tests have been utilised. It was found that cured epoxy-polymers consist of two extreme regions, with low and high crosslink densities, whose volume fractions have been estimated by using a mechanical model applicable for two-phase systems.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2063-2071 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of acrylonitrile initiated by an ascorbic acid-peroxodisulfate redox system was studied in an aqueous solution at 35°C in the presence of air. Molecular oxygen was found to have no effect on the polymerization reaction. An increase in ionic strength slightly increased the rate. The overall rate of polymerization, Rp, showed a square dependence on [monomer] and a half-order dependence on [peroxodisulfate]. A first-order dependence on [ascorbic acid] at low concentrations (〈3.0 × 10-3 mol L-1) followed by a decrease in Rp at higher concentrations of ascorbic acid (〉3.0 × 10-3 mol L-1) was also noted. Rp remained unchanged up to 40°C and showed a decline thereafter. Addition of catalytic amounts of cupric ions decreased the rate whereas ferric ions were found to increase the rate. Added sulfuric acid in the range (6.0-50.0) × 10-5 mol L-1 decreased the Rp.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2327-2331 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2341-2359 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Esters of cyanoacetic acid are a novel class of epoxy curing agents. The model reaction between ethyl cyanoacetate (ECA) and phenyl glycidylether (PGE) yielded a cyano-spiro-dilactone under conditions similar to the resin cure. The structure of the spiro compound resulting from 2 ECA and 2 PGE was elucidated by MS, IR, 1H-, and 13C-NMR techniques. Ammonia is split off from 1 ECA and acts in statu nascendi as a satellite hardener. An overall model reaction equation for the cyanoacetyl cure is proposed. The cure of bisphenol A-diglycidylether (BADGE) with ECA and with neopentylglycol-biscyanoacetate (NPGCA) is described over a wide range of the molar ratio. Clear and tough solids are obtained with a glass transition temperature up to 130°C. Cyanoacetates are latent hardeners requiring a curing initiator. Since N-4-chlorophenyl N′-dimethylurea is a latent initiator, liquid “one-shot” systems can be formulated that are stable at room temperature and harden quickly above 120°C. Heat aging properties of cured specimens are reported. A series of novel liquid, resinous, and crystalline cyanoacetates and their potential as curing agents are described.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2425-2439 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Glow-discharge plasma polymerization of hexamethylcyclotrisiloxane was carried out on the cellulose acetate substrate in the presence of iodine crystal and the effect of I2 doping on liquid permeability such as water, cyclohexane, alcohol homologues, and a water-alcohol mixture was investigated. It was found that I2-doped poly(siloxane) (PHMS-I2) membrane exhibited larger water permeability than nondoped (PHMS) membrane with anomalous pressure dependence (fourth power with pressure gradient). The permeability of alcohol homologues of PHMS membrane increased with increasing the molecular size and the hydrophobicity, whereas that of PHMS-I2 membrane decreased significantly. The presence of a small amount of hemoglobin also increased the water permeability of both membranes. From the results of flow tests of various kinds of fluid it was assumed that these membranes permeate the liquid predominantly by solution-diffusion mechanism.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 2461-2479 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This paper further investigates imide formation in amidation reactions involving Bischloride A2 and suitably selected mono- and difunctional analogues on the one hand, and primary aromatic mono- and diamines on the other. It also investigates the reaction of these acid chlorides with secondary mono- and diamines. If, say, N,N′ dimethyl p-phenylene diamine and hydroquinone dioxyacetyl chloride or bischloride A2 were to react quantitatively, then a linear unbranched polyamide would be expected to be the result which, in the absence of any hydrogen remaining at the amide link, would no longer present a site for further electrophilic attack on the part of the exceptionally reactive aroxyacetyl chloride. There also arises the possibility that a monoamine such as aniline could conceivably act as a difunctional reagent in the presence of aroxyacetyl chlorides. In the event of this reaction proceeding quantitatively one would expect to obtain a linear polyimide in which each imide-nitrogen atom carries a phenyl group. In carrying out the experimental preparative work which is required to elucidate these points we used both monofunctional reactants as model compounds and difunctional reactants in order to assess the polymeric resultants. The products were characterized by means of 1H-NMR, 13C-NMR, IR spectroscopy, TLC, and Tg determinations. The conclusions drawn on the basis of the experimental work provided a satisfactory interpretation of the complex reactions which occur during the polyamidation of bischloride A2. They also point to interesting possibilities for the use of difunctional aroxyacetyl chlorides as modifying comonomers in minor amounts in the preparation of copolyaramides with reduced crystallinity. Such copolyaramides would be expected to have better solubility in common solvents and to be more easily processable than the rather specialized and extremely high-melting polyaramides currently commercially available and could therefore extend the range of useful applications for this class of polymers.The experimental section is preceded by an introduction which briefly reviews the “state of the art,” especially as far as bischloride A2-based polyamidation reactions are concerned. It is followed by a discussion of the results, by the conclusions, and a brief summary.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...