Sulfur Copolymers as Vulcanizing Agents for Unsaturated Rubber

Abstract

The article deals with a new class of sulfur vulcanizing agents, which are prepared by polyadition of octasulfur and styrene oligomers or a mixture of fatty acids from rapeseed oil and by the reaction of polybutadiene and dicyclopentadiene from pyrolytic C₅ fraction. The optimal copolymerisation temperature is 125–150 °C and the optimal content of organics in the vulcanization agents is 10–30 %. Vulcanization characteristics of various rubber mixtures were determined. Mechanical properties of vulcanizates prepared using the sulfur copolymers and those obtained with commercial polymeric sulfur (Sulfur N) are compared. At the same sulfur contents in the vulcanizate, the sulfur copolymers give products of the same or better quality compared with those obtained using polymeric sulfur.