Copolymerization theory of the vulcanization of rubber. VI. Hydrogen sulfide effects and some self‐limiting features

Abstract

Abstract Vulcanization with sulfur is ascribed to the formation of sulfur radicals which are believed to copolymerize with the rubber molecule double bonds. Hydrogen sulfide is proposed as necessary for chain initiation but when formed in sufficient amounts serves as a chain terminator. This is believed to lead to numerous self‐limiting features including ceiling temperatures, post‐vulcanization and delayed action effects. Initiation may result from the oxidation of H 2 S to sulfur radicals and termination to the formation of HS radicals.