摘要
- 4 0℃条件下 ,在 CH2 Cl2 溶剂中以α-氯代乙苯为引发剂 ,Ti Cl4 和 Ti( Oi Pr) 4混合物为 Lewis酸活化剂 ,进行β-蒎烯阳离子聚合 .单独使用强的 Lewis酸 Ti Cl4 时 ,聚合反应在瞬间完成 ,聚合产物的分子量分布较宽 .添加本身无催化活性的弱 Lewis酸 Ti( Oi Pr) 4后 ,聚合反应减缓且聚合产物的分子量分布变窄 .当Ti( Oi Pr) 4/Ti Cl4 摩尔比为 1 /3时 ,产物的分子量随单体转化率线性增加 ,且分子量分布较窄 ,显示出活性聚合特性 .
The cationic polymerization of β pinene was carried out with 1 phenylethyl chloride as an initiator and the mixture of TiCl 4 and tetraisopropoxytitanium[Ti(OiPr) 4] as a Lewis acid activator in CH 2Cl 2 at -40 ℃. The polymerization with strong Lewis acid TiCl 4 alone completed instantaneously and gave the polymers with broad molecular weight distributions. The addition of weak Lewis acid Ti(OiPr) 4 , which alone had no catalytic activity for β pinene, retarded the polymerization by TiCl 4 and led to polymers with narrower molecular weight distributions. When [Ti(OiPr) 4] 0/[TiCl 4] 0=1/3, the number average molecular weight of the polymers increased in direct proportion to monomer conversion, and the molecular weight distribution of the polymers was narrow. The living nature of the polymerization was further demonstrated by monomer addition experiments. 1H NMR analysis of the polymers obtained at \{[Ti(OiPr) 4] 0/[TiCl 4] 0=\}1/3 showed that 1 phenylethyl chloride served as an initiator and generated poly( β pinene) chains with the CH 3CH(C 6H 5) head group and a tert Cl tail group. [WT5HZ]
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第12期1932-1935,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金! (批准号 :2 98740 40 )
国家教育部优秀年轻教师基金资助
关键词
活性阳离子聚合
Β-蒎烯
α-氯代乙苯
引发剂
Living cationic polymerization
β Pinene
1 Phenylethyl chloride
TiCl 4/Ti(OiPr) 4
