QUANTUN CHEMICAL STUDIES ON DELAYED-ACTION VULCANIZATION ACCELERATORS FOR RUBBER

Abstract

Relation between activities (i.e., delayed action, rate of vulcanization, etc.) and chemical structures of sulfenamide-type delayed action vulcanization accelerators for rubber were quantum chemically studied.
Four parameters, which affect greatly on activities of the accelerators, were derived. They were electrophilic reactivity indices on sulfur atoms, radical reactivity indices on nitrogen atoms, π-bond orders between sulfur and nitrogen atoms, and π-electron densities on nitrogen atoms of sulfenamide linkages.
From those results, some new vulcanization accelerators of improved delayed action could be discovered.
Reaction mechanisms of the accelerators were also discussed briefly.