摘要
以聚丁二烯基锂(PBLi)为引发剂、i-Bu3Al为调节剂、环己烷为溶剂,在70~120℃下引发苯乙烯聚合,研究了n(i-Bu3Al)∶n(PBLi)对阻滞苯乙烯聚合行为的影响;并用NMR方法对反应的聚合动力学进行了研究。实验结果表明,加入i-Bu3Al时体系的聚合反应速率降低,n(i-Bu3Al)∶n(PBLi)越大,聚合反应速率越慢,甚至反应完全停滞;当n(i-Bu3Al)∶n(PBLi)=1.0、反应温度由90℃升至120℃时,聚合反应速率大幅加快,1.5 h内苯乙烯转化率达到90%以上。当n(i-Bu3Al)∶n(PBLi)较小时,两者可能形成较高活性的1∶2络合体;当n(i-Bu3Al)∶n(PBLi)较大时可能形成低活性的1∶1络合体,且1∶2络合体自身及其与1∶1络合体之间均存在构型转换。
The retarded anionic polymerization of styrene initiated by polybutadiene lithium (PBLi) / i-Bu3Al at 70 - 120℃ in cyclohexane was investigated. The results showed that the polymerization reaction slowed down to complete stagnation with increasing n(i-Bu3Al) : n(PBLi) from 0.3 to 1.0. The polymerization rate increased rapidly with rise of the reaction temperature at n ( i-Bu3Al ) : n(PBLi) 1.0. It was indicated that 1 : 2 i-Bu3Al/PBLi complex probably formed at low n(i- Bu3Al) : n ( PBLi), which could promote the styrene polymerization at 90℃. At high n ( i-Bu3Al) : n( PBLi), 1 : 1 complex formed and the polymerization rate was considerable just at high temperature (higher than 100 ℃). The reactive activity of the former was higher than the latter and the transformation between them or among 1 : 2 complex might exist.
出处
《石油化工》
CAS
CSCD
北大核心
2011年第5期522-526,共5页
Petrochemical Technology
基金
国家自然科学基金项目50973004
20934001)
关键词
聚丁二烯基锂
三异丁基铝
阻滞负离子聚合
苯乙烯
polybutadiene lithium
triisobutyl aluminum
retarded anionic polymerization
styrene