Li Han, Wang Nasidan, Han Xuefei, Yuan Haoran, Xie Jiang
College of Airworthiness, Civil Aviation University of China, Tianjin 300300, China.
Polymers (Basel). 2021 Feb 14;13(4):569. doi: 10.3390/polym13040569.
For carbon fiber epoxy resin used in aerostructure, thermal degradation mechanism and kinetics play an important role in the evaluation of thermal response and combustion characteristics. However, the thermal decomposition process and mechanism are difficult to unify strictly due to the complexity of the components from different suppliers. In the present study, a product of carbon fiber epoxy resin made by AVIC (Aviation Industry Corporation of China) composite corporation is examined to identify its thermal degradation mechanism and pyrolysis products by measurements, including simultaneous thermal analysis, Fourier transform infrared spectroscopy and mass spectrometry, establish the kinetic model by Kissinger/Friedman/Ozawa/Coats-Redfern methods. The results show thermal degradation occurs in three steps under the inert atmosphere, but in four steps under air atmosphere, respectively. The first two steps in both environments are almost the same, including drying, carbon dioxide escape and decomposition of the epoxy resin. In the third step of inert atmosphere, phenol is formed, methane decreases, carbon monoxide basically disappears and carbon dioxide production increases. However, in air, thermal oxidation of the carbonaceous residues and intermolecular carbonization are observed. Furthermore, thermal degradation reaction mechanism submits to the F model. These results provide fundamental and comprehensive support for the application of carbon fiber epoxy resin in aircraft industry.
对于航空结构中使用的碳纤维环氧树脂，热降解机理和动力学在热响应和燃烧特性评估中起着重要作用。然而，由于不同供应商的成分复杂，热分解过程和机理难以严格统一。在本研究中，对中航工业复合材料公司生产的一种碳纤维环氧树脂产品进行了检测，通过同步热分析、傅里叶变换红外光谱和质谱等测量手段确定其热降解机理和热解产物，采用基辛格/弗里德曼/小泽/科茨-雷德芬方法建立动力学模型。结果表明，在惰性气氛下热降解分三步进行，而在空气气氛下分四步进行。两种环境下的前两步基本相同，包括干燥、二氧化碳逸出和环氧树脂分解。在惰性气氛的第三步中，形成苯酚，甲烷减少，一氧化碳基本消失，二氧化碳生成增加。然而，在空气中，观察到含碳残留物的热氧化和分子间碳化。此外，热降解反应机理符合F模型。这些结果为碳纤维环氧树脂在飞机工业中的应用提供了基础而全面的支持。
