含咪唑离子盐的环辛烯在离子液体中开环易位聚合微观研究  

KINETICS OF RING-OPENING METATHESIS POLYMERIZATION OF CYCLOOCTENE DERIVATIVE IN IONIC LIQUID

作　　者：韩会景[1] 刘经纬[1] 黄炜[1] 宋春梅[1] 张以群[1] 谢美然[1] 

机构地区：[1]华东师范大学化学系,上海200062

出　　处：《高分子学报》2008年第5期492-496,共5页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20474017)资助项目

摘　　要：用核磁共振方法研究了带电荷的环辛烯单体在离子液体和CDCl3中开环易位聚合反应的微观特征，根据单体在化学位移δ=5．66～5．58处双键氢积分峰面积的减少和聚合物主链上不饱和双键氢移至高场δ=5．38～5．39处峰面积积分的增加来表征聚合反应的情况．检测和记录了单体在有离子液体参与的条件下均相聚合反应和在CDCl3中的异相聚合反应过程，根据在不同反应体系中Grubbs第二代崔化剂中与Ru相连的苯亚甲基上氢在核磁图谱上δ=19．2处的峰型变化，探讨在两种介质中的不同聚合行为．研究表明，该单体在离子液体介质中的均相聚合有可控聚合的微观特点，并通过ln[M]0/[M]与反应时间的关系曲线，证实了反应的活性特征．Ring-opening metathesis polymerization （ROMP） is a widespread tool to synthesize well-defined and highly funetionalized polymers. Recently, the ROMP of 5-substituted eyelooctene with the pendant of imidazolium salt catalyzed by Grubbs second generation catalyst [ RuCl2 （ PCy3 ） （SIMes） （CHPh） ] in CH2 Cl2 and ionic liquid was reported. The polymerization, which was carried out in CH2Cl2, afforded much higher number average molecular weights （Mn） and a much broader molecular weight distribution （PDI） than those expected for a living polymerization. These results imply that, with funetionalized eyelooetene monomer propagation is significantly faster than initiation resulting in a poor initiation efficiency. Additionally, the broadening PDI of polymers may be due to its propensity to perform intramoleeular backbiting reactions. This is a general phenomenon in ROMP initiated with [ RuCl2 （ PCy3 ） （SIMes） （CHPh） ] in conventional organic solvents. However, the polymerization, which was carried out in ionic liquid, afforded improved control over the molecular weight and polydispersity of the resultant product （PDI 〈 1.4） .This polymerization showed many of the characteristics of a living system which prompted us to look more closely at the kinetics of this particular system. The first investigation for kinetics of the initiation and propagation of ring-opening metathesis polymerization of 3-methyl- 1- [ （5-eyelooetenyl） oxyearbonylmethylene ] -imidazol- 1-ium tetrafluoroborate catalyzed by [ RuCl2 （ PCy3 ） （SIMes） （CHPh）] in ionic liquid and CDCl3 was carried out by I H-NMR spectroscopy measurement. The decrease in the monomer concentration over time was tracked by the monitoring of the decrease in the resonance of the alkenes protons on the eyelooetenes ring which appeared at 3 = 5.5 - 5.7 relative to an internal standard of CDCl3 . These proton signals shifted upfield to approximately 3 = 5.38- 5.39 as the undertaking of reaction, this indicated that the po

关 键 词：环辛烯衍生物 离子液体 开环易位聚合 动力学 

分 类 号：O631.5[理学—高分子化学]