论文部分内容阅读
用热失重方法分析了聚亚苯基苯并二唑(PBO)纤维在不同气氛中的热分解行为,采用O zaw a法计算了PBO纤维在氮气和空气两种气氛中的热分解活化能。结果表明升温速率对PBO纤维的热分解温度有较大影响;氧气作为热分解反应的引发剂,大大降低了分解反应的活化能;由IR光谱对不同温度裂解产物结构的分析,推测了热氧化降解对PBO纤维分子结构的影响;在不同失重率时几乎相同的热分解活化能,表明无论热分解的气氛如何,PBO纤维的热分解均是一个无规引发的单阶段过程;结合PBO纤维在两种气氛中的热分解机理,解释了分解气氛对残碳率的影响。
The thermal decomposition behavior of polyphenylene benzobisoxazole (PBO) fibers in different atmospheres was analyzed by TG method. The thermal decomposition activation energy of PBO fibers in both nitrogen and air atmospheres was calculated by O zaw a method. The results showed that the heating rate had a great effect on the thermal decomposition temperature of PBO fibers. Oxygen as the initiator of thermal decomposition reaction greatly reduced the activation energy of the decomposition reaction. The IR spectra of the pyrolysis products at different temperatures suggested that thermal oxidation The effect of degradation on the molecular structure of PBO fibers; almost the same thermal decomposition activation energy at different weight loss rates shows that the thermal decomposition of PBO fibers is a randomly initiated single-stage process regardless of the thermal decomposition atmosphere; The thermal decomposition mechanism in both atmospheres explains the effect of the decomposition atmosphere on the residual carbon rate.