论文部分内容阅读
本文利用热分析方法在广泛研究各种聚酰亚胺热氧化裂解的基础上,根据高聚物热氧化裂解的氧化脱氢机理,依实验数据以经验式 T_(20,000)(℃)=a-bK_H描述化学结构中的氢分数K_H与温度指数T_(20,000)之间的关系,由此可粗略地预估聚酰亚胺的温度指数。热重法热氧化裂解表观活化能计算值是随反应程度的增加而降低的;而热解表观活化能具有不变的数值,与化学结构有一定的联系。并对热解动力学作了若干讨论。
Based on the thermal oxidative cleavage of various polyimides by thermal analysis, according to the oxidative dehydrogenation mechanism of thermal oxidative pyrolysis of polymers, the experimental data are obtained according to the experimental data of T 20,000 (° C) = a- bK_H describes the relationship between the hydrogen fraction K_H in the chemical structure and the temperature index T_ (20,000), whereby the temperature index of the polyimide can be roughly estimated. The calculated values of apparent activation energy of thermo-gravimetric thermal oxidative cleavage decrease with the increase of reaction degree. However, the apparent activation energy of pyrolysis has a constant value, which is related to the chemical structure. Some discussions on the kinetics of pyrolysis have also been made.