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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 96 (1992), S. 7109-7115 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Unlike usual polyhydroxilic packing materials for liquid chromatography based on cross-linked agarose, CL-amylose and CL-dextrans (Sephadex), the cross-linked PVA gels exhibit an increase of swelling properties with the reticulation degree, up to a certain limit. Afterwards more advanced reticulation degrees induce a decrease in swelling capacities just as in case of other cross-linked polyhydroxilic polymers. This abnormal behaviour of CL-PVA was supposed as being due to the interchain hydrogen associations. IR spectra, X-ray data and 8 M urea treatments strongly supported our supposition pointing out a maximum association by hydrogen bonds in CL-PVA gels with a reduced degree of reticulation.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 52 (1961), S. 205-212 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The polymerization of large cyclic vinyl compounds is of considerable interest in the interpretation of the mechanism of action of complex organometallic catalysts. Numerous vinyl compounds have been investigated up to now but no study has been made of compounds containing large rings. Studies on the isotactic polymerization of vinylcarbazole have brought to light very important facts permitting of a number of inferences as to the mechanism of isotactic polymerization. Despite the large molecular volume of vinylcarbazole and the steric hindrances that should be expected due to this, a study of the polymerization kinetics has revealed reaction rates similar to those observed in the polymerization of other monomers. The study of the polymerization of vinylcarbazole and of other monomers showed that the butyllithium-titanium chloride catalyst belongs to the class of organometallic complexes that act either by a stepwise or ionic mechanism. The specific features of complex organometallic catalysts in the polymerization of vinylcarbazole are evidently associated with preliminary activation of the active centers during which activation of the monomer also takes place. The formation of polymers with an isotactic microstructure is due to one of the possible mechanism of the catalysis, namely, to nonstepwise action. In the polymerization of vinylcarbazole in the presence of organolithium compounds and titanium tetrachloride the microstructure of the resultant polymer and the rate of polymerization depend upon the formation of other than primary complex compounds. The microstructure of isotactic polyvinylcarbazole shows a particular shape of spherulites, depending upon the nature of the catalyst.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 56 (1962), S. 1-9 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: A description is given of the polymerisation of N-vinylcarbazole in the presence of aliphatic nitroderivatives, which determine in this case the development of the reaction by a cationic mechanism.Further the kinetics of this special polymerisation are shown and the chemical activity of the aliphatic nitroderivatives in the polymerisation process is demonstrated.
    Notes: Es wird die Polymerisation des N-Vinylcarbazols in Gegenwart aliphatischer Nitroverbindungen, die durch kationischen Mechanismus wirken, beschrieben. Weiterhin wird über die Kinetik dieser speziellen Polymerisation sowie über die chemische Reaktionsfähigkeit der aliphatischen Nitroverbindungen in den Polymerisationsprozessen berichtet.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 34 (1983), S. 696-701 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es werden kinetische Untersuchungen der Ringöffnungspolymerisation des Cyclopentens dargestellt, die mit folgenden katalytischen Systemen durchgeführt werden: und Es wird der Einfluß der aluminiumorganischen Verbindung auf die Struktur der Polymere und deren Eigenschaften untersucht. Der Polymerisationsprozeß folgt in beiden Fällen demselben kinetischen Gesetz, welches eine momentane Startreaktion und eine bimolekulare Abbruchreaktion einschließt. Die erhaltenen Polymere weisen unterschiedliche Mikrostrukturen und verschiedene Eigenschaften auf. Der Unterschied ist von der Konzentration der aktiven Zentren, die sich im Falle beider katalytischer Systeme bilden, und von den Nebenreaktionen, die im Polymerisationsprozeß auftreten, abhängig.
    Notes: The report presents kinetic studies on the ring opening polymerization of cyclopentene carried out with the following catalytic systems: and The relation between the nature of the aluminium-organic compound, the structure of the polymers and some of their properties was also investigated. The polymerization follows in both cases the same kinetic pattern which include an instantaneous initiation and a bimolecular termination reaction. The resulting polymers present different microstructures and properties due to the different concentrations of active centers, which occur in the presence of the two investigated catalytic systems and to side reactions during the polymerization process.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 8 (1970), S. 777-782 
    ISSN: 0449-296X
    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
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 8 (1970), S. 95-110 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: By means of the kinetic equations of polymerization some approximate relations were deduced by using the concomitant rate of change of intrinsic viscosity in many concrete cases. These relations were easy to handle and were sufficiently precise for direct calculation of the rate constants of polymerization.A detailed mathematical study was carried out to improve the suggested approximations as well as the extension of these considerations.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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