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Titolo:
Photocrosslinking reaction of vinyl-functional polyphenylsilsesquioxane sensitized with aromatic bisazide compounds
Autore:
Yasuda, N; Yamamoto, S; Wada, Y; Yanagida, S;
Indirizzi:
Mitsubishi Electr Corp, Adv Technol R&D Ctr, Amagasaki, Hyogo 6618661, Japan Mitsubishi Electr Corp Amagasaki Hyogo Japan 6618661 Hyogo 6618661, Japan Osaka Univ, Grad Sch Engn, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 ch Engn, Suita, Osaka 5650871, Japan
Titolo Testata:
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
fascicolo: 24, volume: 39, anno: 2001,
pagine: 4196 - 4205
SICI:
0887-624X(200112)39:24<4196:PROVPS>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Keywords:
polyphenylsilsesquioxane; silicone ladder polymer; vinyl-functional polymer; photocrosslinking reaction; aromatic azide compounds; molecular orbital calculation; inorganic polymers; photochemistry; polysiloxanes;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
25
Recensione:
Indirizzi per estratti:
Indirizzo: Yasuda, N Mitsubishi Electr Corp, Adv Technol R&D Ctr, Tsukaguchihonmachi,Amagasaki, Hyogo 6618661, Japan Mitsubishi Electr Corp Tsukaguchihonmachi Amagasaki Hyogo Japan 6618661
Citazione:
N. Yasuda et al., "Photocrosslinking reaction of vinyl-functional polyphenylsilsesquioxane sensitized with aromatic bisazide compounds", J POL SC PC, 39(24), 2001, pp. 4196-4205

Abstract

fPhotochemical reactions of aromatic azide groups were applied for a novelphotosensitive silicone ladder polymer, that is, partially vinyl-substituted polyphenylsilsesquioxane sensitized with aromatic bisazide compounds as a photocrosslinker. The photocrosslinking reaction in this system was investigated from the viewpoint of the efficiency of the photocrosslinker, that is, the ratio of the photocrosslinker consumed for crosslinking. The numbers of photodecomposed azide groups and crosslinks in the polymer were determined by Fourier transform infrared measurements. At a higher bisazide concentration, the predominant reaction of nitrenes formed as the intermediary radical by the photolysis of azide was a coupling reaction that could not contribute to the gelation of the polymer. The ratio of the bisazide compoundconsumed for crosslinking showed the highest value at its concentration of3 wt % ( and decreased with the addition of a larger amount. The semiempirical molecular orbital calculations were applied to the theoretical analysis of the photoreaction of nitrenes using phenylnitrene as a model structure. The calculation results indicated that the coupling reaction of nitrenes should proceed more easily than the photocrosslinking reaction in N-2 atmosphere, and the fact that the oxidation of nitrenes should proceed exclusively in the atmosphere including O-2 agreed with the experimental results. (C) 2001 John Wiley & Sons, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 06/04/20 alle ore 08:34:58