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Molecular weight changes in polyacrylates on ultraviolet irradiation
Author(s) -
McGill W. J.,
Ackerman L.
Publication year - 1975
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1975.070191012
Subject(s) - acrylate , irradiation , oxygen , ethyl acrylate , polymer chemistry , polymer , molar mass distribution , photodissociation , nitrogen , methyl acrylate , gel permeation chromatography , acrylate polymer , chemistry , ultraviolet , reaction mechanism , photochemistry , materials science , copolymer , organic chemistry , catalysis , physics , optoelectronics , nuclear physics
Films of poly(methyl acrylate), poly(ethyl acrylate), and poly( n ‐butyl acrylate) were irradiated by means of a high‐pressure mercury lamp in oxygen and nitrogen atmospheres, and the molecular weight changes accompanying degradation were studied as a function of radiation dose. Crosslinked material was formed in all cases though less crosslinking occurred in oxygen than in nitrogen atmospheres. Scission was the major reaction in the photo‐oxidation of poly(ethyl acrylate), and this was explained in terms of acetal formation. In a nitrogen atmosphere, the proportion of units fractured to the proportion of units crosslinked per unit radiation dose was constant for the three polymers. Gel permeation chromatographic studies showed the accumulation of low molecular weight fragments on prolonged photolysis, and this was explained in terms of a chain reaction mechanism.