应用高分子分子设计合成节能丁苯橡胶──Ⅱ．链结构形成机理

SYNTHESIS OF SAVE-ENERGY S-SBR BY MOLECULAR DESIGN OF MACROMOLECULES──Ⅱ THE FORMATION MECHANISM OF CHAIN STRUCTURE

用阴离子法合成ＳＢＲ，多官能团锂为引发剂，环巳烷为溶剂，极性添加剂为无规化剂和结构调节剂。对苯乙烯、１．２－结构单元在分子链上的分布情况进行了研究。对丁苯共聚物的共聚组成、序列分布、微观结构的形成机理进行了探讨。认为在聚合体系中同时存在有丁二烯的π烯丙基活性种、σ烯丙基活性种及苯乙烯活性种。丁二烯与σ烯丙基活性中心反应主要形成１．４－结构，同π烯丙基中心反应主要形成１．２－结构。对于π烯丙基活性中心而言，还存在苯乙烯与丁二烯的竞争反应。

The formation mechanism of composition,sequence distribution and microstructure of S-SBR which was synthesized by using polyfunctional lithium as initiator,cyclohexane as solvent and by adding additive to control the structure of copolymer chain was studied. There are π-allyl active centre and σ-allyl active centre of polybutadiene and styrene active centre in the polymerization system at the same time. Butadiene reacted with σ-allyl active centre to form mainly 1, 4-structure and 1, 2-structure too when reacted with π-allyl active centre.There exists a competitive reaction between butadiene and styrene when they reacted with σ-allyl active centre. The reactive probability between different active centres and monomers depended on the kind and concentration of polar additive in the polymerization system.