Photodegradation and photo-oxidation of poly(vinyl chloride) in solution

Abstract Quantum yields of dehydrochlorination and of main chain scission were determined for photolysis of PVC in solution in tetrahydrofuran and 1,2-dichloroethane. The observed auto-accelerated degradation results from an increased absorption of light by the growing polyene structures. The presence of oxygen enhances the efficiency of dehydrochlorination, chain scission and crosslinking processes. From the constant quantum yields, it is inferred that energy transfer occurs from the absorbing polyenes and that initially present unsaturations are responsible for initiation of the degradation.