ISSN:
0887-624X
Keywords:
polyisobutylene
;
photooxidation
;
thermooxidation
;
FTIR spectrometry
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Polyisobutylene films (PIB) were submitted to a thermal oxidation at 100°C and to a photooxidation by exposure to long-wavelength radiations (λ ≥ 300 nm) at 60°C. The modifications of the chemical structure resulting from the oxidation were determined by FT-IR analysis of the polymer films, coupled to chemical treatments that converted specifically the oxidation products. Dissolution of oxidized samples permitted analysis of the polymer by 13C- and 1H-NMR. The structure of the volatile products was determined by mass spectroscopy analysis of the gas phase. Identification of the numerous products formed permitted the proposal of a scheme that accounts for the oxidation of PIB. When the irradiations are carried out at a temperature above 50°C, the depolymerization is favored and the mechanism involves two main routes of oxidation. A direct oxidation starts with the oxidation of radicals obtained by homolysis of the C—C bonds on the main chain, and an induced oxidation involves hydrogen abstraction on the methylene and methyl groups by radicals formed by the direct oxidation of the polymer. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1689-1701, 1997
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
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