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  • Physics  (2)
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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 6 (1968), S. 945-950 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Chlorine gas has been shown by previous investigators to initiate the polymerization of solid N-vinylcarbazole at room temperature, giving a maximum yield of 66% polymer after 18 hr. This initiation of polymerization of N-vinylcarbazole without the application of heat, by a gas, is the only solid-state initiation other than those that are radiation-induced known to us. This study was undertaken in order to determine both the scope and the mechanism of the room-temperature solid-state initiation of vinyl polymerization of N-vinylcarbazole by gases. The gases (HCl, Cl2, and N2O4) were absorbed by solid N-vinylcarbazole, giving very rapid exothermic polymerization: HCl, 37% polymer yield, M̄n 2500; Cl2, 50% polymer yield, M̄n 4703; N2O4, 91% polymer yield, M̄n 7073. The gases NOCl, BF3, and HBr were not absorbed by N-vinylcarbazole and did not initiate polymerization. The N2O4-initiated polymerization, which gave a high yield of polymer, was complete within 5 min. after introduction of gas. This polymerization method and the resulting polymer compared favorably with conventional peroxide-initiated melt polymerization and the polymer obtained thereform. The mechanism of gas-initiated polymerization, which was studied with introduction of inhibitors, appears to be classically cationic in nature.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 7 (1969), S. 2757-2762 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel polyimide forming reaction is reported. Pyromellitic dianhydride undergoes a condensation polymerization with diphenylmethane diisocyanate in solution or under melt-fusion conditions to give polydiphenylmethanepyromellitimide (II) and carbon dioxide. Polymer II was characterized by inherent viscosity, infrared spectrum, and thermogravimetric analysis. An intermediate Polymer I was isolated which appeared to contain seven-membered rings in the backbone. It is postulated that these rings eliminate carbon dioxide to form polyimide II.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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