循环湿热环境中CCF300/5405复合材料的吸湿脱湿行为

研究了CCF300碳纤维/5405双马树脂复合材料在71 ℃恒温水浸循环吸湿-脱湿行为。试样经过三次饱和吸湿-脱湿过程, 探讨不同循环次数CCF300/5405复合材料的吸湿率和水分扩散速率变化, 并采用SEM观察纤维/基体界面变化, 分析了造成循环湿热环境下复合材料体系吸湿-脱湿变化的原因。研究结果表明: CCF300/5405复合材料的吸湿行为基本满足Fick第二定律, 并且在水浸14天后达到饱和吸湿状态, 饱和吸湿率约为0.66%; 材料吸湿处理后, 纤维与基体间的界面遭到水分破坏, 产生大量空隙和裂纹, 使水分的扩散速率明显增加, 饱和吸湿率略有增大, 并且这种破坏不可逆。 

Moisture absorption and desorption behavior of CCF300/5405 composites in cyclic hygrothermal environment

The cyclic moisture absorption and desorption behavior of CCF300 carbon fiber/5405 bismaleimid composites immersed in 71 ℃ distilled water were investigated. After three cycles of moisture absorption-desorption process, moisture diffusion coefficient and moisture uptake of CCF300/5405 composites in different cycles were studied. Using SEM, the change mechanism of absorption behavior of composites in the hygrothermal condition was discussed. The results show that the moisture absorption behavior of CCF300/5405 composites basically conforms the Fick's second law. After 14 days of moisture absorption, the composites reach to the saturated moisture level, and saturated moisture uptake is about 0.66%. Additionally, after cycles of moisture absorption process, the interface between fiber and matrix is damaged by moisture, which leads to a large number of voids and cracks. As a result, water diffusion coefficient increases significantly and saturated moisture uptake rises slightly. Furthermore, the damage is irreversible even after the moisture desorpion.