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Environmental effects on latex paint coatings. II. CP/MAS 13 C‐NMR and XPS investigations of structural changes in the base polymer
Author(s) -
Sankar S. S.,
Patil D.,
Schadt R.,
Fornes R. E.,
Gilbert R. D.
Publication year - 1990
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.1990.070410533
Subject(s) - polymer , copolymer , vinyl chloride , magic angle spinning , dehydrohalogenation , polymer chemistry , x ray photoelectron spectroscopy , vinyl acetate , materials science , acrylate , nuclear chemistry , chemistry , organic chemistry , chemical engineering , nuclear magnetic resonance spectroscopy , catalysis , engineering
Films of a base polymer, primarily a terpolymer of n ‐butyl acrylate, vinyl acetate, and vinyl chloride, that is used in latex paint, have been exposed to various combinations of UV/air, UV/SO 2 , and UV/SO 2 /H 2 O. Reported here are results of elemental analyses, XPS and 13 C magic angle spinning NMR of the exposed samples. When samples are exposed to UV/SO 2 or UV/SO 2 /H 2 O, there is clear evidence of the incorporation of sulfur into the polymer, and there is significant loss of the acetate group in the copolymer. There is also evidence of the formation of unsaturated carbon–carbon bonds which is due to loss of the acetate groups and some dehydrohalogenation. During the time scale of exposures, changes in the composition and structure of samples exposed to UV/air were not detected by the techniques considered here although some chain scission and crosslinking undoubtedly occur. The results suggest a synergistic interaction between SO 2 and UV leading to rapid degradation of the polymer, and that the presence of atmospheric SO 2 pollutants can have an adverse effect on the lifetime of latex coating materials.