Catalyst- and additive-free light-induced oxidative polymerization of diphenyl disulfides for the facile synthesis of polyphenylene sulfides

Abstract

A catalyst- and additive-free light-induced oxidative polymerization of diphenyl disulfides under an oxygen atmosphere is reported for the synthesis of polyphenylene sulfides. This synthetic strategy can be efficiently initiated by UV or visible light, achieving an optimal yield of 89% under blue LEDs (400 nm) and a maximum number-average molecular weight (Mn) of 2571 g/mol under UV LEDs (365 nm). The applicability of this method is further demonstrated by the polymerization of some diaryl disulfides bearing dimethyl or dimethoxy substituents. Mechanism verification experiments reveal that the polymerization proceeds via a light-induced aggregation-enabled free radical polymerization pathway.