异丁烯与对甲基苯乙烯共聚合反应竞聚率的测定

摘要

在-80℃下,以2-氯-2,4,4-三甲基戊烷(TMPCl)/四氯化钛(TiCl4)/2,6-二叔丁基吡啶(DtBP)为引发体系,氯甲烷(CH3 Cl)/环己烷(Chx)(体积比为50/50)为溶剂采用正离子聚合技术研究异丁烯与对甲基苯乙烯的共聚行为.研究异丁烯与对甲基苯乙烯不同投料比以及不同转化率下的共聚组成,利用Kelen - Tudos与Yezreielv - Brokhina - Roskin法计算单体的竞聚率；用1H-NMR方法测定异丁烯和对甲基苯乙烯共聚物组成.结果表明,在低转化率(小于15％)的条件下,异丁烯与对甲基苯乙烯的竞聚率分别为r1 =0.248,r2=1.190.%The block copolymerization of isobutylene with />-methylstyrene was studied in 2-chloro-2,4, 4-trimethylpentane(TMPCl)/ titanium tetrachloride(TiCl4)/ 2,6-dHert-butylpyridine(DtBP)as initiating system in methyl chloride(CH3Cl)/cyclohexane(Chx)(50/50 v/v)solvent mixture at -80 °C by cationic polymerization. The compositions of the copolymers were analyzed by l H-NMR. The reactivity ratios of isobutyene and ^-methylstyrene were calculated by Kelen-Tudos (K-T) methods and Yezreielv-Brokhina-Roskin calculative method (YBR), respectively. The experimental results showed that at the low changing rate(<15%) ,the values of reactivity ratios for isobutylene and />-methylsty-rene are ri=0. 248 and r2 = l. 190 respectively.