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Molecular weight measurement in weathered polymers
Author(s) -
O'Donnell B.,
White J. R.,
Holding S. R.
Publication year - 1994
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.1994.070521109
Subject(s) - polypropylene , polystyrene , gel permeation chromatography , polymer , degradation (telecommunications) , ultraviolet , materials science , polymer degradation , ultraviolet light , polymer chemistry , polyethylene , chemical engineering , composite material , telecommunications , optoelectronics , computer science , engineering
Gel permeation chromatography has been used to monitor the molecular weight changes that occur when polymers are degraded by photooxidation. Methods of sample preparation and procedures for conducting the chromatography measurements and for analyzing the results are discussed. Examples are given of applications to studies of polystyrene (PS), polypropylene (PP), and glass fiber‐reinforced polypropylene (GFPP) exposed to ultraviolet (UV) irradiation in the laboratory. The results show that the degradation rate is fastest near the exposed surface, but in PS and PP, degradation is much faster at the unexposed surface than in the center of the molding, where the UV intensity is greater than at the unexposed surface. It is deduced that degradation at the center is slowed by a shortage of oxygen. © 1994 John Wiley & Sons, Inc.