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  • 1960-1964  (18)
  • 1
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 43 (1960), S. 509-516 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Chain transfer constants of the end groups (CE) and of the middle portions (CM) of the polymer chain of polyethylene glycol and its dodecyl ether were determined at 60°C. in vinyl acetate polymerization. In the case of polyethylene glycol, CE and CM represent the chain transfer constants of (HO—C2H4—) and that of (—CH2CH2O—) which were estimated as 0.004 and 0.0017 respectively, and were compared with the chain transfer constants of propanol and ethanol. The chain transfer constant of the dodecyl radical in polyethylene glycol dodecyl ether is estimated as 0.001, which is in fairly good agreement with that obtained theoretically from the chain transfer constant of the methylene group in acetic esters, but not from that in alcohols. This situation may be attributed to the inhibition of resonance energy transfer by the etherlike oxygen atom.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    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: Unter Verwendung von Schwefelsäure-Sulfat-Komplex-Katalysatoren konnte in nichtpolaren Lösungsmitteln bei Zimmertemperatur ein isotaktischer Polyvinylisobutyläther erhalten werden. Als Sulfate wurden Al-, Mg- und Cr-Sulfat verwandt. Die erhaltenen Polymeren besaßen eine größere Stereospezifität als die Polymeren die bei -78°C mit Hilfe von BF3·O(C2H5)2 hergestellt worden waren. Mit steigender Polymerisationstemperatur fiel die Stereospezifität der Polymeren nicht ab, sondern stieg eher noch schwach an.
    Notes: Using H2SO4 metal sulfate complex catalysts, in non-polar solvents isotactic polyvinyl isobutyl ether was obtained at room temperature. Al, Mg, and Cr sulfates were used as metal sulfates. These polymers had a higher regularity than that of polymers which were polymerized by BF3 · Et2O at -78°C. In the polymerization by these complex catalysts, the stereoregularity of the resultant polymer did not change or rather increased slightly with the raise of temperature.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 62 (1963), S. 208-210 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 54 (1962), S. 226-229 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 46 (1960), S. 539-541 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 60 (1962), S. S26 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    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: Die Geschwindigkeitskonstanten der Wachstumsreaktion (kp) der Polymerisation von Vinylisobutyläther und Vinyl-2-chloräthyläther mit Jod als Initiator wurden in Äthylenchlorid und in n-Hexan nach der in Teil I beschriebenen Methode bestimmt. Auch hier stieg der kp-Wert mit steigender Dielektrizitätskonstante des Systems an. Die erhaltenen kp-Werte standen mit den Copolymerisationsparametern der erwähnten Monomeren in guter Übereinstimmung, was gleichfalls für die Bestimmungsmethode von kp spricht.
    Notes: Rate constants of the propagation reaction (kp) of isobutyl vinyl ether and 2-chloroethyl vinyl ether initiated by iodine were obtained in ethylene chloride and in n-hexane by the method proposed in the proceeding paper. Also in these systems, it was noticed that kp value increased as the dielectric constant of the polymerization system increased. kp values of these two monomers mentioned above were compared with their monomer reactivity ratio and it was proved that the numerical values which we obtained coincided well with each other. Thus, the method of determination of kp applied here must have been reasonable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 8
    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: Für die kationische, durch Jod initiierte Polymerisation von Styrol in äthylenchlorid wurde der Häufigkeitsfaktor (Ap) und die Aktivierungsenergie der Wachstumsreaktion (ΔEp ≠) bestimmt und Werte von 102 l/Mol·sec bzw. 6,5 kcal/Mol gefunden. Dieser Wert für (Ap) ist viel geringer als bei der radikalischen Polymerisation, was auf den Einfluß des Gegenanions zurückgeführt wird. Diese Annahme wurde durch statistische Betrachtungen experimentell erhaltener kp-Werte belegt.
    Notes: The pre-exponential factor (Ap) and the activation energy (ΔEp ≠) of the propagation constant were determined on the cationic polymerization of styrene initiated by iodine in ethylene chloride, the obtained values being about 102l./mole·sec. and 6.5 kcal./mole respectively. The pre-exponential factor obtained here is much smaller than that of the propagation constant of the radical polymerization. The extraordinarily small Ap value was considered to come from the interaction of the counter anion, and from the statistic consideration experimentally obtained kp value was proved to be reasonable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 42 (1960), S. 535-544 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The present investigation is concerned with the relationship between P, the reactivity of a radical, and Q that of a monomer in the propagation reaction. At first, P values are calculated from the accumulated data of the rate constants of the propagation reaction. From these results, the relation is shown to be represented by the following equation: \documentclass{article}\pagestyle{empty}\begin{document}$ \log {\rm }P = kQ + a(k 〈 0) $\end{document} where k and a are constants. The P values in the termination reaction (Pt) are also calculated, and the relation between these values and Q values are examined. The results show that the similar relation found in the propagation reaction holds in this step too. By applying the method of Evans and co-workers, a sufficient explanation for this equation is not obtained, but the analogous equation can be derived. The present authors suggest that the inverse proportion between log P and Q appears to be based on the following different principles: (1) the inverse proportion between the magnitude of localization energy of the radical and that of monomer, and (2) the linear free energy relationship found in organic chemistry.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    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: Versuchsweise wird eine Methode für die Bestimmung der Geschwindigkeitskonstanten der Wachstumsreaktion (kp) im stationären Zustand der kationischen Polymerisation vorgeschlagen. Als Beispiele der Anwendung werden die kp-Werte der Polymerisation von mit Jod initiiertem p-Methoxystyrol in Äthylenchlorid und Tetrachlorkohlenstoff bestimmt. Die kp-Werte steigen merklich mit der Dielektrizitätskonstanten des Polymerisationsmediums an. Die Richtigkeit der Annahmen, von denen die angewandte Methode abhängt, wird geprüft, und sie erwiesen sich als vernünftig.
    Notes: A tentative method for the determination of the rate constant of the propagation reaction (kp) in the stationary state of cationic polymerization was proposed, and as an example of its application, kp values of p-methoxystyrene initiated by iodine were obtained in ethylene chloride and in carbon tetrachloride. It was found that kp value increased remarkably as the dielectric constant of the polymerizing solution increased. The proprieties of the suppositions upon which the method applied here depended were examined and proved to be reasonable.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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