微悬浮法氯乙烯醋酸乙烯酯共聚树酯的热降解反应动力学研究

STUDY OF KINETICS AND THERMAL DEGRADATION MECHANISM OF VINYL CHOLORIDEVINYL ACETATE COPOLYMER PREPARED BY MINCROSUSPENSION POLYMERIZATION

用热重分析技术对微悬浮法氯乙烯—醋酸乙烯酯共聚树脂的热降解反应进行了研究 ,结果表明 :氯乙烯—醋酸乙烯共聚树脂在热分解过程中 ,HCl和HAc同时脱出 ;在静态空气和静态氮气 ,升温速率为 5、1 0℃min-1的条件下 ,共聚树脂的热降解均为二级反应 ,热降解表观活化能Ea为 :1 60 .82～ 1 83 .77KJ .mol-1;ln[A/s]为 2 8.64～ 3 4.74。

The kinetics of the thermal degradation of vinyl chloride vinyl acetate copolymer prepared by microsuspension polymerization was studied by thermogravimetric technigue.The results showed that MS PC/VAc give off hydrogen chloride and acetate acid at the same time when it was heated.The kinetic parameters were obtained from an analysis of TG DTG curves by integral and differential methods.The activation energy is about 160.82 183.77kJ/mol and Arrhenius frequency factor ln(A/s) is 28.64 34.74 in the different condition.The most probable kinetic model functions were suggested by comparison of the kinetic parameters.It was found that the model functions of the thermal degradation of MS PC/VAc were consistant with the reaction of the second order at heating rate of 5,10℃/min at the statics air and N 2 respectively.Mathematical expressions for the kinetic compensation effect were derived.