Some New Chemicals for Rubber and Their Reactivities as Free Radical Sources

Abstract

The present paper is concerned with investigations about some new chemicals for rubber processing. The actions of the chemicals were classified into several types according to their selective activities. Chemicals having the tendency to abstract hydrogen atom from rubber molecules act as crosslinking agents or peptizers according to the nature of the radical produced and to the presence of oxygen. Benzoyl disulfide and diazothioether were found to be new vulcanizing agents and the quaternary ammonium salts of the aromatic series, sulfinic acids and alkyl nitrites were new peptizers for rubber. The chemicals composed of stable radical species acting as acceptors for sulfur radicals were found to be antiscorch agents. Chloro- or nitroso-compounds of imide, imine, alcohol, or mercaptan were found to have such characters. Aliphatic quaternary salts producing radicals with moderate activity on heating may open the sulfur rings. The vulcanization characteristics of some synthetic rubbers were found to be improved by using of some modifiers such as thioacetamide, trichloroisocyanuric acid, and trichloromelamine.