VULCANIZATION OF EPICHLROHYDRIN RUBBER BY THE SYSTEMS COMPRISING THIURAM COMPOUNDS

Abstract

Vulcanization of epichlorohidrin rubber was investigated using the systems comprising thiuram compounds. Thiuram compounds were activated with strongly basic metal compounds, such as calcium hydroxide to give the vulcanizates of improved properties. The most active of thiuram compounds was dipentamethylenethiuram tetrasulfide, which contained the longest polysulfide linkage.
Furthermore thiuram compounds exhibited a synergestic effect with thioureas. In this composite vulcanization systems the metal compounds added as acid scavangers were limited by the adaptability toward the both components, calcium hydroxide and ceric oxide being assumed to be favorable.
The above-mentioned vulcanization systems could be applied to the covulcanization of epichlorohydrin rubber with unsaturated rubber provided that proper choice of metal compounds was made.