Kinetic decomposition models for the thermal decomposition of a high-performance polymeric material (Polyimide, PI) were determined from specific techniques. Experimental data from thermogravimetric analysis (TGA) and previously elucidated decomposition mechanism were combined with numerical simulating tool to establish a comprehensive kinetic model for the decomposition of PI under three atmospheres: nitrogen, 2% oxygen, and synthetic air. Multistaged kinetic models with subsequent and competitive reactions were established by taking into consideration the different types of reactions that may be occurring during the thermal decomposition of the material (chain scission, thermo-oxidation, char formation). The decomposition products and decomposition mechanism of PI which was established in our previous report allowed for the elucidation of the kinetic decomposition models. A threestaged kinetic thermal decomposition pathway was a good fit to model the thermal decomposition of PI under nitrogen. The kinetic model involved an autocatalytic type of reaction followed by successive nth order reactions. Such types of models were set up for the evaluation of the kinetics of the thermal decomposition of PI under 2% oxygen and in air, leading to models with satisfactory fidelity.

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高性能材料的氧浓度和热分解建模：聚酰亚胺（Cirlex）的案例研究

高性能聚合物材料（聚酰亚胺，PI）热分解的动力学分解模型是通过特定技术确定的。将热重分析 (TGA) 的实验数据和先前阐明的分解机制与数值模拟工具相结合，建立了 PI 在三种气氛下分解的综合动力学模型：氮气、2% 氧气和合成空气。考虑到材料热分解过程中可能发生的不同类型的反应（断链、热氧化、焦化），建立了具有后续和竞争反应的多阶段动力学模型。在我们之前的报告中建立的 PI 的分解产物和分解机制允许阐明动力学分解模型。三阶段动力学热分解路径非常适合模拟 PI 在氮气下的热分解。动力学模型涉及自催化类型的反应，然后是连续的 n 级反应。建立这种类型的模型是为了评估 PI 在 2% 氧气和空气中的热分解动力学，导致模型具有令人满意的保真度。