二氧化碳-环氧丙烷-丙交酯三元共聚物的合成与表征及其热解动力学研究  

SYNTHESIS,CHARACTERIZATION AND THERMAL DEGRADATION KINETICS OF CARBON DIOXIDE-PROPYLENE OXIDE-D,L-LACTIDE TERPOLYMER

作　　者：王佳力[1,2] 刘素琴[1] 黄可龙[1] 刘艳飞[1] 吴维康[1] 

机构地区：[1]中南大学化学化工学院,长沙410083 [2]生物医学与健康工程研究所转化医学研究与发展中心中国科学院深圳先进技术研究院,深圳518055

出　　处：《高分子学报》2011年第6期687-693,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20976197);高等学校博士学科点专项科研基金(基金号20090162120013)资助项目

摘　　要：通过二氧化碳(CO2)、环氧丙烷(PO)与D,L-丙交酯(D,L-LA)的三元开环共聚,得到一种新型热塑性脂肪族聚碳酸酯(PPCLA).对PPCLA结构进行了FTIR、1H-NMR、13 C-NMR及1H-1H COSY表征,表明D,L-LA开环嵌入PO-CO2分子链中,并对共聚过程聚合机理进行了初步探讨.同时设计并引入一种新的计算方法,非线性约化法(NLA),通过与FWO和Tang两种无模型方法比较,前者所得表观活化能(Ea)值更接近Vyazovkin无模型法,各转化率下的平均相对误差小于6.5%.整个分解过程表观活化能值处于66.6～140.3kJ.mol-1之间.非等温热分解动力学研究表明,PPCLA热分解反应分为多步.A novel terpolymer of carbon dioxide,propylene oxide（PO） and D,L-lactide（D,L-LA） was synthesized successfully at 70℃ in toluene by using a polymer-supported bimetallic complex（PBM） as a catalyst.The terpolymer prepared was characterized by FTIR,1H-NMR,13C-NMR and 1H-1H COSY spectrum measurements,which showed D,L-LA was ring-opened and inserted into the backbone of PO-CO2 with the fixed molar ratio of PO and D,L-LA as 5∶1.Furthermore,the expected reaction mechanism suggested the initiation of PO was more facile than that of CO2.Meanwhile,a new computational method called nonlinear approximation method was introduced in this work to analyse the thermal degradation kinetics.FWO and Tang methods as well as nonlinear approximation method were chosen to calculate the apparent activation energy.The results showed the accuracy of this new method was high and the average relative error was less than 6.5% due to its more scientific calculation process when Vyazovkin model free method was chosen as the standard method.During the whole degradation process,the apparent activation values（Ea） were between 66.6 kJ·mol-1 and 140.3 kJ·mol-1,indicating a better thermal stability related with the higher Ea as compared with that of PPC in the early decomposition stage.The results of non-isothermal degradation kinetics also suggested the whole pyrolysis of the terpolymer was a multi-step process due to variation of Ea.

关 键 词：聚碳酸酯 二氧化碳 热分解动力学 

分 类 号：O631.3[理学—高分子化学]