湿热–高温循环老化对环氧乙烯基酯树脂/玻璃纤维复合材料性能影响

Influences of Cyclic Hygrothermal-Thermal Aging on Properties of Epoxy Vinyl Ester Resin/Glass Fiber Composites

对玻璃纤维增强环氧乙烯基酯树脂基复合材料进行湿热–高温循环加速老化试验,分析了复合材料在不同循环老化周期次数下的质量变化、吸湿率变化、表面元素含量、红外光谱、表面宏微观和断口形貌、树脂初始分解温度及弯曲强度。结果表明,在湿热老化过程中,复合材料的质量损失率和吸湿率随循环老化周期次数的增加逐渐增大;在水分子的扩散、水解反应和热氧老化共同作用下,复合材料试样表面产生大量裂纹、树脂发生老化降解、纤维与树脂基体界面出现脱粘,同时循环老化造成树脂分子链断裂,树脂交联密度下降,导致树脂初始分解温度下降;循环老化6个周期后,复合材料的弯曲强度为449.17 MPa,弯曲强度保留率为76.63%。

The glass fiber reinforced epoxy vinyl ester resin composite was subjected to a damp hygrothermal-thermal cycle accelerated aging test,and the quality change,moisture absorption rate change,surface element content,infrared spectrum,surface macro-micro and fracture morphology,initial decomposition temperature and bending strength of composites under different cyclic aging cycle times were analyzed.The results show that during the humid heat aging process,the mass loss rate and moisture absorption rate of the composite gradually increases with the cyclic aging times increases.Under the combined action of the diffusion of water molecules,hydrolysis reaction and thermal and oxygen aging,a large number of cracks are generated on the surface of the composites,the resin ages and degrades,and the interface between the fiber and the resin matrix debonds,and cyclic aging causes the breakage of the resin molecular chain and the decrease in the resin crosslink density,the initial decomposition temperature of the resin decreases.After 6 cycle of cyclic aging cycle,the flexural strength of the composite is 449.17 MPa and the retention rate of flexural strength is 76.63%.