环烷氧锡引发β-丁内酯开环聚合动力学与立体化学  

Ring Opening Polymerization of β-Butyrolactone Initiated with Distannoxane Kinetics and Stereochemistry

作　　者：魏志勇[1] 刘炼[2] 张步峰[1] 杨璠[1] 齐民[1] 

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024 [2]大连海事大学机电与材料工程学院,辽宁大连116026

出　　处：《高分子材料科学与工程》2007年第3期92-95,99,共5页Polymer Materials Science & Engineering

基　　金：国家高技术863项目(2004AA32G110);辽宁省自然科学基金资助项目(20032124)

摘　　要：采用膨胀计法研究环烷氧锡引发β-丁内酯开环聚合动力学,表明链增长反应对单体浓度和引发剂浓度的反应级数分别为1和0.56。13C-NMR分析聚合物中二单元组和三单元组序列结构,由二单元组序列结构分析求得引发剂对单体形成间同规整性的活化能差(Es-Ei)值为-13 kJ/mol,由三单元组序列结构分析符合链端立构控制的Bernoulli模型。The kinetics of （R,S）β-butyrolactone polymerization initiated with a new distannoxane compound were investigated at various monomer/initiator ratios and reaction temperatures with dilatometer. According to the kinetics studies, chain propagation rate for β-butyrolactone polymerization using distannoxane were first order in monomer concentration and 0.56 order in initiator concentration, respectively. ^13C-NMR spectra analysis of stereochemical sequence distributions at various polymerization temperatures for the distannoxane showed activation energy （△E = Es--Ei） of ca. -13 k J/tool for syndiotactic versus isotactic diad formation. The triad stereosequence distributions of the synthetic P3HB agreed well with the Bernoulli model of chain end stereocontrol. Theses analyses show that distannoxane initiator produces preferentially syndiotactic polyesters （syndiotactic diad fraction from 0.6 to 0.7）.

关 键 词：肛丁内酯 聚-β-羟基丁酸酯 环烷氧锡 动力学 立体化学 

分 类 号：TQ316.341[化学工程—高聚物工业]