聚酰亚胺纤维增强环氧树脂结构透波复合材料的性能研究及机制分析

Study on properties and mechanism of polyimide fiber reinforced epoxy resin structure wave-transmitting composites

选择聚酰亚胺纤维和环氧树脂,采用热熔法制备出了聚酰亚胺/环氧结构透波复合材料。通过傅里叶变换红外光谱、吸湿率、力学性能、介电性能、湿热老化性能以及扫描电子显微镜等表征手段,研究了聚酰亚胺/环氧结构透波复合材料的结构透波性能和耐湿热环境性能。研究结果表明:聚酰亚胺纤维中刚性共轭结构赋予了聚酰亚胺纤维复合材料良好的透波性能和耐湿热性能,但是与石英纤维增强环氧树脂复合材料相比,聚酰亚胺纤维增强环氧树脂结构透波复合材料仍存在着压缩强度、弯曲强度与层间剪切强度低、吸湿率高的问题;力学性能破坏模式分析结果显示,聚酰亚胺纤维同时存在有机纤维的吸湿、压缩强度低、纤维/树脂界面结合差的问题。

Polyimide fiber and epoxy resin were selected,and the polyimide fiber/epoxy structure wavetransmitting composite material was prepared by hot melt method. By the means of Fourier transform infrared spectroscopy,moisture absorption,mechanical properties,dielectric properties,hygrothermal aging properties and scanning electron microscopy,the structural wave-transmitting properties and hygrothermal environment resistance of polyimide/epoxy structure wave-transmitting composites were studied. The research results showed that the rigid conjugate structure in the polyimide fiber gave the polyimide fiber composite with good wave-transmitting properties and hygrothermal resistance. However,compared with the quartz fiber reinforced epoxy resin composite,the polyimide fiber reinforced epoxy resin structure wave-transmitting composite still had the problems of low compression strength,flexural strength and interlaminar shear strength,and high moisture absorption rate. The results of failure mode analysis of mechanical properties showed that polyimide fiber also had the problems of moisture absorption of organic fiber,low compressive strength and poor fiber/resin interface bonding.