双官能团硫脲催化丙交酯开环聚合反应的理论研究  

Theoretical Study on the Ring-opening Polymerization of D-Lactide Catalyzed by Bifunctional Thiourea Catalyst

作　　者：朱荣秀[1] 张冬菊[1] 王若曦[2] 刘成卜[1] 

机构地区：[1]山东大学化学与化工学院,济南250100 [2]山东警察学院刑事科技系,济南250014

出　　处：《化学学报》2008年第8期885-889,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.20633060,20773078)资助项目

摘　　要：用密度泛函理论在B3LYP/6-31G(d)水平上研究了双官能团硫脲催化丙交酯开环聚合反应的微观机理.讨论了催化聚合反应的两条可能路径:路径A和路径B.计算结果表明沿路径A进行的开环聚合反应在能量上是有利的.从理论上证实了催化剂在聚合反应中所起的双官能团催化作用,即氨基活化引发剂,硫脲活化单体,通过两个基团共同作用,完成催化开环.The Ring-opening polymerization （ROP） of D-lactide （D-LA） catalyzed by bifunctional thiourea catalyst has been studied by performing density functional theory calculations at the B3LYP/6-31G（d） level. Two pathways （A and B） for the catalyzed ROP of D-LA have been characterized in detail. It has been found that path A is much more favorable in energy than path B. The calculated results indicate that the catalyst promotes the ROP of D-lactide by bifunctional activation of the carbonyl of LA monomer and of the initiating/propagating alcohol via hydrogen bonding to the thiourea group and to the Bronsted basic （tertiary amino） group, respectively. The calculated results provide a general model that explains the mechanism of the title reaction.

关 键 词：双官能团硫脲 开环聚合 丙交酯 反应机理:密度泛函理论 

分 类 号：O631.5[理学—高分子化学]