循环湿热环境中CCF300/5405复合材料的吸湿-脱湿行为

摘要

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.%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。