Studies on photodegradation of poly(vinyl chloride) (part 1)

Films prepared from emulsion polymerized poly(vinyl chloride) were subjected at 0°C to accelerated photodegradation in air using a weatherometer. Photooxidation and scission of the main chain took place but dehydrochlorination or formation of polyenes was not observed. The absorption of the carbonyl group indicating oxidation was found at 1725cm−1 in the infrared absorption spectrum. Only when tetrahydrofuran, which had been used for the preparation of films, was left in the films, an absorption was also found at 1770cm−1. Oxidation occurred at the position of the methylene carbon and the cut end of the main chain. As a result of the X‐ray photoelectronic spectrum (ESCA) analysis, it was found that the carbonyl concentration was higher in the surface layer of the sample than in the interior thereof.