二氧化碳-氧化环己烯共聚物的合成和热性能研究  

SYNTHESIS AND THERMAL PROPERTIES OF CARBON DIOXIDE-CYCLOHEXENE OXIDE COPOLYMERS

作　　者：李国法[1,2] 秦玉升[1] 王献红[1] 赵晓江[1] 王佛松[1,3] 

机构地区：[1]中国科学院长春应用化学研究所高分子材料工程实验室,长春130022 [2]中国科学院研究生院,北京100039 [3]中国科学院,北京100864

出　　处：《高分子学报》2010年第1期107-113,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20634040)资助项目

摘　　要：采用三元催化剂(Y(Cl3COO)3-ZnEt2-glycerin)催化二氧化碳与氧化环己烯共聚反应,制备了高分子量二氧化碳与氧化环己烯共聚物(PCHC).8 h内催化剂平均活性达到11.8 kg polymer/mol Zn,PCHC主链上碳酸酯单元含量大于95%,数均分子量达到7.0×104.研究了PCHC的玻璃化转变温度和分子量的关系,当PCHC的数均分子量(Mn)低于8.5×104时,玻璃化转变温度(Tg)随Mn增加而升高;Mn高于8.5×104时,Tg对Mn的依赖性不大.当PCHC的分子量充分高时,其玻璃化转变温度可以达到120℃,PCHC的自由体积特征常数K=1.91×105.研究了聚合物分子量对其热稳定性的影响,结果表明提高分子量有利于提高PCHC的热分解温度.通过实施聚合反应和后处理,三元催化剂转化为相应的金属氧化物(主要为氧化锌)残留在聚合物中,采用Kissinger方法得到纯PCHC(除去金属氧化物)的热分解表观活化能约为199.9 kJ/mol,含金属氧化物(Zn含量4400×10-6)PCHC的热分解表观活化能下降为143.9 kJ/mol.因此氧化锌能够促进PCHC的热降解,减少PCHC中氧化锌的含量有利于改善PCHC的耐热性能.Cyclohexene oxide copolymer（PCHC） with high molecular weight was synthesized using ternary rare earth metal coordinate catalyst（Y（Cl_3COO）_3-ZnEt_2-glycerine）.The catalytic activity reached 11.8 kg polymer/（mole Zn） under optimal condition,the obtained PCHC showed number average molecular weight（M_n） of 7.0×104,with carbonate unit over 95%.The glass transition temperature（T_g） of PCHC was between 110℃ and 120℃,it increased with increasing M_n when M_n was below 8.5×104,and leveled between 119℃ and 120℃ when M_n was over 8.5×104.The highest T_g may be reached as 120℃ if the M_n of PCHC is high enough,and the characteristic free volume constant K is 1.91×105.The influence of molecular weight on thermal stability of PCHC was investigated,raising molecular weight was beneficial for improving thermal stability of PCHC,and a 60℃ increase of the onset degradation temperature was observed when M_n increased from 39.9×103 to 93.1×103.Since the rare earth ternary catalyst changed to metal oxide（mainly ZnO） after polymerization and post-polymerization treatments,the influence of Zn content on thermal stability of PCHC was studied based on Kissinger method,PCHC with Zn content below 5×10-6 showed surface activation energy for thermal decomposition of 199.9 kJ/mol,whereas it decreased to 143.9 kJ/mol for PCHC with Zn content of 4400×10-6.Therefore,reducing Zn content could improve the thermal stability of PCHC.

关 键 词：二氧化碳 二氧化碳-氧化环己烯共聚物 热降解 热稳定性 

分 类 号：O631.3[理学—高分子化学]