聚酰亚胺纸基材料的热老化研究∗

摘要

利用热失重分析了不同厚度聚酰亚胺(PI)纸基材料的热稳定性,采用 Coats-Redfern 法计算 PI 纸基材料的分解动力学参数,并预测其长期使用上限温度。实验结果表明：在氮气气氛中,PI 纸基材料具有很好的热稳定性,且厚度越大,热稳定性越好。通过 Coats-Redfern 方法得知,PI 纸基材料的热分解反应为二级反应；厚度较大的PI 纸基材料具有较高的活化能 E 和使用上限温度,且不同厚度的 PI 纸基材料的耐热等级均为 H 级以上。最后,利用扫描电子显微镜和傅里叶变换红外光谱仪对 PI 纸基材料的热分解机理进行了分析。%The thermal stability of polyimide (PI)paper-based materials with different thickness was analyzed by thermo-gravimetric.The Coats-Redfern method was applied to calculate the decomposition kinetic parameters and predict the ceiling temperature in long-term use of PI paper-based materials.The results showed that PI paper-based materials had good thermal stability in nitrogen atmosphere,and the thicker PI paper had better thermal stability.By the method of Coats-Redfern,reaction order of thermal decomposition of PI paper-based materials closed to 2.Thicker PI paper-based materials possessed higher activation energy E and higher ceiling temperature,and the temperature classification of PI paper-based materials with different thickness was above H.Finally,SEM and FTIR were used to analyze the thermal decomposition mechanism of PI paper-based materials.