不同湿热条件下碳纤维/环氧复合材料湿热性能实验研究

Experimental research on hygrothermal properties of carbon fiber/epoxy resin composite under different hygrothermal conditions

对比研究了环氧5228A树脂及碳纤维/环氧5228A树脂复合材料层合板在3种湿热环境(水煮、70℃水浸,70℃85%相对湿度)下的湿热性能,考察了湿热条件对复合材料层间剪切性能的影响规律,并从吸湿特性、物理化学特性、树脂力学性能、湿应力等方面分析了不同湿热环境下复合材料性能衰减的机制。研究表明,碳纤维/高温固化环氧树脂复合材料层间剪切性能主要是由吸湿率决定,相同吸湿率不同湿热条件下性能的下降幅度基本相同;3种湿热条件下该树脂及其复合材料未发生化学反应、微裂纹等不可逆变化,复合材料层合板湿热老化机制主要是吸入水分后基体增塑和树脂、纤维湿应变不一致导致的湿应力对复合材料性能的负面作用。

The hygrothermal properties of high-temperature curing epoxy 5228A resin and carbon fiber/ epoxy 5228A resin composite laminate were investigated under three different hygrothermal conditions,i.e.boiling water,water immersion and relative humidity 85% at 70℃.The effects of hygrothermal condition on the interlaminar shear strength of the carbon fiber/epoxy resin composite laminates were studied.The hygrothermal aging mechanism was analyzed based on the moisture absorption,physical and chemical properties,the mechanical properties property of epoxy resin and moisture stress.The results show that the degradation degree of the interlaminar shear strength mainly depends on the moisture content,and the degradation degrees under different hygrothermal conditions are almost identical at the same water absorption content.The chemical change and interface micro-cracks have not been found in the composite laminate under the three hygrothermal conditions.The resin plasticization with water absorption and moisture stress due to different moisture expansion between fiber and resin is the main reasons for the degradation of the composites laminate.