Dependence of the properties of synthetic isoprene rubber hydrochloride on the degree of hydrochlorination

Abstract

IT ItAS been shown that by reaction of cis-1,4-polyisoprene with hydrogen chloride a hydrochloride of the rubber is formed, and this has film-forming properties [1-3]. Satisfactory physicomechanical properties are obtained when the degree of reaction is 85%, corresponding to 29% of combined chlorine [4]. For preparation of a film from polyisoprene hydrochloride it is necessary that the original rubber should be stereoregular. Attempts to obtain synthetic atactic polyisoprene hydrochloride in fihn form have been unsuccessful. The rubber, which is originally amorphous at room temperature, crystallizes during reaction with hydrogen chloride [5]. The laws governing the change in properties of the rubber during hydrochlorination have not yet been studied. This problem can be solved by a detailed study of the variation in properties of intermediate products of hydrochlorination in the transition from the amorphous rubber to the crystalline rubber hydrochloride, and this forms the subject of the present paper.