CR-g-BA的合成及热降解动力学分析

Synthesis and Thermal Degradation Kinetics Analysis of CR-g-BA

在N_2气氛条件下,用TGA和DTGA研究了甲基丙烯酸丁酯与氯丁橡胶接枝共聚物(CR-g-BA)的热降解过程.结果表明,聚合物降解分三步完成,第一步的热降解温度约为513～653 K,第二步的热降解温度约为660～790K,第三步的热降解温度约为790～1000K.其中第三步热降解的终止温度明显受升温速率的影响.用Achar方程和Coats-Redfern方程对30种常见的机理函数进行计算比较,得到第一步热降解平均活化能E=234.35kJ·mol^(-1),热降解的积分机理函数g(a)=[-ln(1-a)]~3,频率因子lnA=33.48;热降解的微分机理函数f(a)=(1-a)[-ln(1-a)]^(-2)/3,频率因子lnA=48.90.

The thermal degradation of CR-g-BA in nitrogen is studied with TGA and DTGA in the atmosphere of N2. The results show that the thermal degradation of the polymer is a three-step reaction. The temperatures of thermal degradation is 513K to 653K in the first step, 660K to 790K in the second, and 790K to 1000K in the third, in the final step the temperature of thermal degradation is affected by the increasing of the heating rate. Compared the 30 species common mechanism function with Achar method and Coats-redfem method, the results show that the average activation energy in thermal degradation process of the first step was 234.35 kJ·mol^-1, the total mark function of the thermal degradation mechanism was g（a） = [-ln（1-a）]^3, and frequency factor lnA =33.48, the differential function of the thermal degradation mechanism was f（a） = （1-a）[-ln（1-a）]^-2/3, frequency factor lnA =48.90.