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  • Articles  (57)
  • Polymer and Materials Science  (43)
  • 550 - Earth sciences  (7)
  • Crystal Structure  (7)
  • 1990-1994  (57)
  • 1970-1974
  • 1993  (30)
  • 1991  (27)
  • 1
    Electronic Resource
    Electronic Resource
    Trägerkatalysatoren aus C12-allylnickel(II)-komplexen [Ni(C12H19)]X (X = SbF6, O3SCF3) und amorphem aluminiumfluorid in toluol als modell-katalysatoren für das technische katalysatorsystem Ni(octanoat)2/BF3·OEt2/AlEt3 zur 1,4-cis-polymerisation des butadiens39. Mitteilung über Komplexkatalyse, 38. Mitteilung vgl. Lit.15. (1993)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 194 (1993), S. 1273-1288 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The η3, η2, η2-dodeca-2(E), 6(E), 10(Z)-trien-1-yl-nickel(II) complexes [Ni(C12H19)]X (X = SbF6, O3SCF3) were treated in toluene with amorphous aluminium trifluoride (which was prepared from AlEt3 and BF3 · OEt2) in a mole ratio 1 : 10 to 20, forming a highly active catalyst for the 1,4-cis polymerization of butadiene. This catalyst is comparable in its activity and selectivity, and in the molar mass distribution of the polybutadiene, with the technical nickel catalyst Ni(O2CR)2/BF3ċOEt2/AlE3 developed by Bridgestone Tire Company thirty years ago. The existence of the C12-allynickel(II) cation [Ni(C12H19)]+ on the AlF3 support could be proved by FAB mass spectroscopic measurements. In agreement with our reaction model for the allyl nickel complex catalyzed butadiene polymerization, it is concluded that the technical nickel catalyst in its effective structure can be described as a polybutadienylnickel(II) complex co-ordinated to a polymeric fluoroaluminate anion via a fluoride bridge.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1993.021940502
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  • 2
    Electronic Resource
    Electronic Resource
    Synthese und Kristallstruktur des Nonaselenids [Sr(15-Krone-5)2]Se9 (1993)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 416-420 
    Details
    ISSN: 0044-2313
    Keywords: Nonaselenide ; Synthesis ; Crystal Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of the Nonaselenide [Sr(15-crown-5)2]Se9The title compound was prepared by the reaction of excess selenium with strontium diselenide in DMF in the presence of 15-crown-5. [Sr(15-crown-5)2]Se9 forms black crystals, which are soluble in DMF. They were characterized by FIR spectroscopy and by an X-ray structure determination.Space group P21/n, Z = 4, 2 381 observed unique reflections, R = 0.073. Lattice dimensions at 19°C: a = 1 228.7, b = 1 893.4, c = 1 575.7 pm, β = 99.15°. The compound consists of [Sr(15-crown-5)2]2+ ions in which the strontium ion is coordinated by the oxygen atoms of the crown ether molecules in a sandwich-like fashion, and of Se92- ions with a chain structure, which has a topolocical resemblance with the bicyclic ion Se102-.
    Notes: Die Titelverbindung entsteht durch Einwirkung von überschüssigem Selen auf Strontiumdiselenid in Dimethylformamid (DMF) in Gegenwart von 15-Krone-5. [Sr(15-Krone-5)2]Se9 bildet schwarze, in DMF leicht lösliche Kristalle, die durch das FIR-Spektrum und eine röntgenographische Strukturanalyse charakterisiert werden.Raumgruppe P21/n, Z = 4, 2 381 beobachtete unabhängige Reflexe, R = 0,073. Gitterabmessungen bei 19°C: a = 1 228,7; b = 1 893,4; c = 1 575,7 pm, β = 99,15°. Die Verbindung besteht aus [Sr(15-Krone-5)2]2+-Ionen, in denen das Strontiumion sandwichartig von den O-Atomen der beiden Kronenethermoleküle umgeben ist, und kettenförmigen Se92--Ionen, die topologische Verwandtschaft zu dem bicyclischen Se102--Ion aufweisen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19936190229
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  • 3
    Electronic Resource
    Electronic Resource
    Studies on new non-shrinking, thermally stable araldite-type photopolymers with pendent arylacryloyl-groups. I. Photoreaction of some aryl acrylic-acid methyl esters in solution (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 190 (1991), S. 33-52 
    Details
    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: Arylacrylsäuren, wie Furylacrylsäure und Thienylacrylsäure können durch Knoevenagel-Reaktion der Arylcarbaldehyde mit Malonsäure in Pyridin dargestellt werden. Durch einfache Veresterung der Arylacrylsäuren in Methanol/Schwefelsäure werden die entsprechenden Arylacrylsäuremethylester mit guten Ausbeuten erhalten. Diese isomerisieren bei Bestrahlung mit UV-Licht (λ ≥ 280 nm) in methanolischer Lösung. Bei der Photoreaktion in Lösung wurde keine Photodimerisierung beobachtet. Die Reaktionskinetik der Photoreaktionen wurde untersucht.
    Notes: Aryl acrylic acids, e. g. furyl acrylic acid or thienyl acrylic acid are readily formed by the Knoevenagel condensation reaction of arylcarbaldehydes and malonic acid in pyridine. Esterification of these acids with methanol/sulfuric acid gives the corresponding aryl acrylic acid methyl esters in good yields. In methanolic solution these methyl esters isomerize upon irradiation (λ 280 nm). No photodimerization was observed. Kinetic data are given.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051900103
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  • 4
    Electronic Resource
    Electronic Resource
    Ölfettsäremodifizierte wäßrige Polymethacrylatdispersionen (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 204 (1993), S. 127-137 
    Details
    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: Water-borne paints have received greater attention. Existing concepts related to suitable binders are polymethacrylate dispersions crosslinkable by autoxidation. Essential synthesis steps of such dispersions and characteristic properties also of adequate coatings are described.Oil fatty acid structure units are enriched in the shell-region of the dispersed particles and the rest of nearly 30% is localized in the water phase as substituent of a water-soluble copolymer.
    Notes: Wäßrige Anstrichsysteme setzen sich in zunehmendem Maße durch. Als eine Entwicklungsvariante für diesbezüglich geeignete Bindemittel kommen autoxidativ vernet zende Polymethacfrylatdispersionen in Betracht. Es werden wesentliche Schritte der Synthese derartiger Dispersionen un dcharakteristische Eigenschaften auchvon Beschichtungen vorgestellt.Die Ölfettsäurestruktureinheiten sind im Schalenbereich der disperigierten Teilchen angereichert, und sie befinden sich außerden zu etwa 30% in der wäßrigen Phase als Substituenten eines löslichen Copolymeren.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052040112
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  • 5
    Electronic Resource
    Electronic Resource
    Modelluntersuchungen zur topologie der härtung geordneter epoxidnetzwerke (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 211 (1993), S. 61-77 
    Details
    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: 4-Phenyl-4-(2,3-expoxypropyl)benzoate (I) can be cured to thermoset networks with a different degree of order by using isomeric aminophenyl aminobenzoates II to V as curing agents. The formation of intermediates during the curing reaction was studied by means of model compounds. From the reaction of the monoamino-substituted phenylbenzoates VI to IX the reactivities for the primary and the secondary aminoprotons towards epoxide was determined. The kinetic data were used for a stepwise simulation of the curing reaction. Arguments were found that in case of diamines with 4-aminobenzoate structure well ordered intermediates are formed, which crosslink in an early stage of the reaction.
    Notes: Die Härtung von 4-Phenyl-4-(2,3-epoxypropoxy)benzoat (I) mit den isomeren Aminophenylaminobenzoaten II bis V führt zu unterschiedlich geordneten Epoxidnetzwerken. Die Bildung verschiedener Intemediate während der Härtungsreaktion wurde anhand von Modellverbindungen studiert. Aus der Reaktion der monoamino-substituierten Phenylbenzoate VI bis IX mit Epoxid wurden die Reaktionskostanten für die Addition an das primäre und das sekundäre Wasserstoffatom der Aminogruppen bestimmt. Die kinetischen Daten lassen sich für eine schrittweise Simulation des Härtungsverlaufs verwenden. Es wurden Argumente dafür gefunden, daß sich bei Verwendung der Amine mit 4-Aminobenzoat-Strukturen gut geordnete, schnell vernetzende Intermediate bilden.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052110106
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  • 6
    Electronic Resource
    Electronic Resource
    Lichtinduzierte Polymer- und Polymerisationsreaktionen, 4746. Mitteilung: H.-J. Timpe, E. Küstermann, H. Böttcher, Eur. Polym. J., im Druck.. Photopolymersysteme mit α-sulfonyldesoxybenzoinen als initiatoren (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 189 (1991), S. 219-225 
    Details
    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: α-Sulfonyldesoxybenzoine lassen sich aus Desylchlorid und Natriumarylsulfinaten in guten Ausbeuten erhalten. Die Quantenausbeuten bei ihrer Photolyse betragen etwa Φin = 0,50. Im Vergleich zu anderen Photoinitiatoren verläuft die mit α-Sulfonyldesoxybenzoinen initiierte Polymerisation von Methylmethacrylat in Acetonitril nur mit mäßigen Quantenausbeuten, wogegen der Vergilbungsgrad von mit diesen Verbindungen ausgehärteten Harzen wesentlich geringer ist.
    Notes: α-Sulfonyl deoxybenzoines are formed by the reaction of desylchloride with sodium arylsulfinates in good preparative yields. The photolysis of these compounds proceeds with quantum yields of about Φin = 0.50. Compared to other photoinitiators, α-sulfonyl deoxybenzoines polymerize methylmethacrylate in acetonitrile solution with moderate polymerization quantum yields only. On the contrary, the yellowing of cured polyester resins using these compounds as photoinitiators is much smaller.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051890120
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  • 7
    Electronic Resource
    Electronic Resource
    Oxygen permeability in polymers, IIIPart I see ref.5; part II see ref.4.. Dependence of the oxygen permeability on the chemical structure of styrene-maleic acid-copolymers (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 192 (1991), S. 93-101 
    Details
    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 Sauerstoffpermeabilität von Halbestern und Halbamiden der Styrol-Maleinsäure-Copolymeren und weiterer carboxygruppenhaltiger Polymerer wurde im Vergleich mit kommerziellen glasbildenden Polymeren bei Raumtemperatur untersucht. Die Löschung der verzögerten Fluoreszenz von Pyronin B diente zum Nachweis des Sauerstoffs im Polymerfilm.Die Sauerstoffpermeabilität des Styrol-Maleinsäureanhydrid-Copolymeren und der Halbester und Halbamide (Pox = 2…7°10-14 cm2/Pa·s) ist vergleichbar mit der von Polymeren ohne Carboxygruppen wie Polymethylmethacrylat (PMMA) oder Polyvinylacetat (PVAc) und liegt damit etwa eine Größenordnung über der von Polyacrylsäure (PAAc), Styrol-Maleinsäure-Copolymeren (SMAc) oder Carboxymethylcellulose (CMC). Vermutlich konkurrieren intramolekulare H-Brücken in den Halbestern/Halbamiden erfolgreich mit der intermolekularen Wechselwirkung und bewirken damit ebenso wie raumfüllende Substituenten eine Erhöhung der Permeabilität. Zusatz von Basen wie Dimethylaminopropanol (DMAP) und Dimethylaminopropylacrylamid (DMAPAA) senkt die Permeabilität auf bis zu 1/40 des Ausgangswertes ab, was der niedrigen Permeabilität von Polymeren mit vorherrschender ionischer Wechselwirkung (Na-Polyacrylat (NaPAAc), Na-Carboxymethylcellulose (NaCMC) nahekommt.
    Notes: The paper gives a report on the oxygen permeability in films of poly(styrene-comaleic acid) halfesters and halfamides as well as other polymers containing carboxylic groups in comparison with commercially available glass forming polymers at room temperature. The presence of oxygen in the polymer layers was proved by the quenching of the delayed fluorescence of pyronin B. The permeability of the halfesters/halfamides (Pox = 2…7.10-14 cm2/Pa .s) corresponds to that of common polymers like poly(methyl methacrylate) (PMMA) or poly(vinyl acetate) (PVAc), and is nearly one order of magnitude higher than that of poly(acrylic acid) (PAAc), poly(styrene-comaleic acid) (SMAc) and carboxymethylcellulose (CMC). Presumably, intramolecular hydrogen bonds in the halfester/halfamides compete successfully with the intermolecular interactions and hence cause an increase in permeability as also do bulky substituents. Addition of bases like dimethyl aminopropanol (DMAP) and dimethyl aminopropyl acrylamide (DMAPAA) decreases the permeability to about 1/40 of the initial value. The permeability is then similar to the low permeability of polymers with predominant ionic interaction sodium polyacrylate (NaPAAC), sodium carboxymethylcellulose (NaCMC)).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051920108
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  • 8
    Electronic Resource
    Electronic Resource
    GEORDNETE EPOXIDNETZWERKE AUS 4-GLYCIDYLPHENYL-4-GLYCIDYL-BENZOAT und 3- BZW. 4-AMINOPHENYL-4-AMINOBENZOAT Herrn Prof. Dr. D. Braun zum 60. Geburtstag gewidmet (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 185 (1991), S. 33-42 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The introduction of mesogenic groups in main- and sidechains of epoxy thermosets results in an ordered multiphase network with cellular structure, if gelation occurs below the maximal cure temperature Tmax. Tmax is individual for a given combination of monomers. The multiphase network consists of relatively soft anisotropic cell nuclei and hard isotropic cell walls. If gelation occurs above Tmax single phase networks are obtained. The size of the cell nuclei strongly depends on the used monomers and varies up to two orders of magnitude. The multiphase structure was found to have no impact on the tensile elastic modulus.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051850104
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  • 9
    Electronic Resource
    Electronic Resource
    Der Einfluß des Photoinitiators auf die radikalische Härtung von Siliconacrylaten, 98. Mitt. vgl.10. (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 206 (1993), S. 171-191 
    Details
    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 photo-induced, free-radical network formation of silicone acrylates has been investigated in the presence of several photoinitiators containing benzoyl groups. The crosslinking process can be described by means of a free-radical chain process. From calorimetrical measurements it is inferred that oxygen inhibits and terminates the chain propagation process. Both the reaction rate and the inhibition time of the crosslinking are proportional to the air pressure, to the intensity of the incident light, and to the quantum yield of the initiator photolysis.The reaction starts when all oxygen is consumed in the silicone layer. Using Fick's 1st diffusion law it can be show that only oxygen, which diffused into the system, determines the final conversion.Contrary, O2 influences the reaction rate, the inhibition time, and the final conversion. The network density does not depend on the oxygen concentration.The negative influence of oxygen on the reaction rate, on the inhibition time, and on the final conversion can be reduced by means of a high rate of the start reaction which depends on the incident light intensity, light absorption, and the quantum yield of the initiator photolysis.By means of two kinetical methods it is possible to show that any initiator used exhibits a different initiating efficienty; their relative order has been estimated.
    Notes: Die photoinduzierte radikalische Vernetzung von Siliconacrylaten wurde mit verschiedenen Photoinitiatoren vom Benzoyltyp untersucht. Die Photovernetzung derartiger Produkte kann mit Hilfe eines radikalischen Kettenprozesses beschrieben werden. Aus kalorimetrischen Messungen folgt, daß Sauerstoff den Kettenprozeß inhibiert und terminiert, wobei dei Vernetzungsgeschwindigkeit und die Inhibierungszeit Funktionen des Luftdrucks, der Lichtintensität und der Quantenausbeute der Initiatrophotolyse sind.Der Vernetzungsprozeß kann nur beginnen, wenn der Sauerstoff in der Schicht verbraucht ist. Mit Hilfe des 1. Fickschen Diffusionsgesetzes kann gezeigt werden, daß der in das System eindiffundierende Sauerstoff auch den Grenzumsatz bestimmt.Obwohl Sauerstoff in der Schicht die Reaktionsgeschwindigkeit, die Inhibierungszeit und den Grenzumsatz bestimmt, wurde jedoch überraschenderweise festgestellt, daß Sauerstoff auf die Netzwerkdiche keinen Einfluß besitzt.Der negative Effekt des Sauerstoffs auf den Vernetzungsprozeß kann durch eine hohe Startgeschwindigkeit (Funktion der Lichtintensität, der Absorption und der Quantenausbeute der Initiatorphotolyse) reduziert werden.Mit Hilfe von zwei kinetischen Methoden wurde ermittelt, daß die Initiierungseffizienzen der verwendeten Initiatoren verschieden sind, wobei relative Abstufungen bestimmt werden konnten.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052060115
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  • 10
    Electronic Resource
    Electronic Resource
    Mechanisms and kinetics of the anionic polymerization of acrylates, 3.Part 2: cf. ref.2. Effect of lithium chloride and lithium tert-butoxide on the oligomerization of tert-butyl acrylate (1993)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 194 (1993), S. 625-636 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The influence of lithium tert-butoxide (tBuOLi) and of lithium chloride on the oligomerization of tert-butyl acrylate (tBuA) initiated by tert-butyl α-lithioisobutyrate (tBiB-Li) was investigated. These additives affect both the kinetics and the product distribution. Whereas the addition of LiCl leads to a narrower molecular-weight distribution (MWD) the presence of tBuOLi induces broader MWD's, characterized by a very high fraction of the dimer. Both additives decrease the rates of propagation to different degrees. These effects are discussed on the basis of the formation of aggregates and adducts, the lithiated dimer having a higher tendency to form aggregates than the other oligomers. The stability of the growth centres in this oligomerization is increased in the presence of these additives, tBuOLi exhibiting a much stronger effect than LiCl. The interaction of the lithiated dimer with the additives could not be demonstrated in the IR spectra of these mixtures.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1993.021940222
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