Polymérisation cationique du chloro-1 butadiène et copolymérisation avec l'isobutène

Abstract

The cationic homopolymerization of 1-chlorobutadiene and its copolymerization with isobutene have been carried out in dichloromethane solution. The catalyst-cocatalyst pairs used were AlEt 2Cl-(CH 3) 3CCl and AlEtCl 2-(CH 3) 3CCl. In the latter case, the use of (CH 3) 3CCl was not necessary. According to experimental conditions, high molecular weight copolymers ( M n = 200,000 ) insoluble in CH 2Cl 2, or soluble low polymers ( M n = 20,000 ) were obtained. Homopoly-1-chlorobutadienes were soluble low molecular weight polymers ( M n = 10,000 ). The 1-chlorobutadiene units in the polymers are nearly exclusively 3,4 (mainly trans). Consequently, this method is not convenient to prepare elastomers with a 1,4 structure similar to that of chlorinated butyl rubber.