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Polymer degradation. V. Changes in molecular weight distributions during sonic irradiation of polyisobutene
Author(s) -
Porter Roger S.,
Cantow Manfred J. R.,
Johnson Julian F.
Publication year - 1967
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.1967.070110302
Subject(s) - gel permeation chromatography , irradiation , molar mass distribution , polymer , degradation (telecommunications) , distribution (mathematics) , polymer degradation , molecular mass , materials science , chemistry , analytical chemistry (journal) , polymer chemistry , chromatography , composite material , organic chemistry , physics , mathematics , enzyme , telecommunications , mathematical analysis , computer science , nuclear physics
Gel permeation chromatography was used to follow changes in the molecular weight distribution of a polyisobutene, initial M v = 466,000, during degradation induced by sonic irradiation. Seven samples taken at times of 200–163,500 sec. were studied. In general, a steady decrease in molecular weight was observed, although a bimodal distribution was present after 20,000 sec. irradiation. Various measures of inhomogeneity, M w / M n , U , etc., were examined. The function, σ n / M w , where σ n is the standard deviation of the number distribution, is considered as a measure of the relative distribution. It is shown to be almost constant throughout the degradation.