Photolytic degradation of some poly(alkylene polysulfides)

Poly(methylene disulfide), poly(methylene tetrasulfide), poly(ethylene disulfide), and poly(ethylene tetrasulfide) have been subjected to ultraviolet radiation in vacuum at 50°C. Weight losses during photolysis include both low molecular weight compounds and readily condensable polymeric materials; the latter account for the greater proportion of the weight losses. Carbon monosulfide, isolated as its polymer, and hydrogen sulfide are major photolytic products. Carbon disulfide is a major product from the methylene but not from the ethylene polymers. The tetrasulfide polymers during irradiation from volatile products which on condensation give the original polymer. A mechanism of degradation compatible with these findings is suggested.