尼龙无纺布结构化增韧层增韧碳纤维/环氧树脂复合材料的湿热力学性能

采用尼龙无纺布(PNF)作为结构化增韧层,制备了PNF层间增韧改性的U3160碳纤维增强3266环氧树脂(U3160-PNF/3266)复合材料,研究了U3160-PNF/3266复合材料的面内力学性能及湿热老化后的力学性能变化,并分析了复合材料湿热老化前后的层间形貌。结果表明:PNF增韧层的引入并未导致复合材料面内力学性能的下降,与未增韧的U3160碳纤维增强3266环氧树脂(U3160/3266)复合材料相比,增韧复合材料U3160-PNF/3266的90°拉伸性能有所提高。而湿热老化处理对U3160-PNF/3266复合材料的基体和界面性能影响相对明显,尤其是尼龙纤维与树脂基体之间的界面结合性能,湿热老化处理后增韧复合材料的90°压缩和层间剪切性能保持率均明显低于未增韧复合材料的。

Hygrothermal mechanical properties of carbon fabric/epoxy composites toughened by structural toughening layer of polyamide non-woven fabric

U3160 carbon fabric reinforced 3266 epoxy composites toughened by polyamide nonwoven fabric (PNF) (U3160-PNF/3266) were fabricated using PNF as structured toughening layer. Both the in-plane mechanical properties of U3160-PNF/3266 composites and the effect of hygrothermal ageing on mechanical properties were investigated. The interlaminar morphological analysis of the composites was also performed before and after hygrothermal ageing. The results show that the use of PNF as toughening layer does not lead to the decline of in-plane mechanical properties of composites. Meanwhile tensile properties of the toughened U3160-PNF/3266 composites in 90° even slightly increase compared with untoughened U3160 carbon fabric reinforced 3266 epoxy (U3160/3266) composites. While the matrix and interfacial properties of U3160-PNF/3266 composites are noticeable influenced by hygrothermal ageing, especially for the interfacial bonding property between the nylon fiber and the resin matrix. The retention rates of properties of compression in 90° and interlaminar shear of the toughened composites are lower than those of the untoughened composites obviously after hygrothermal ageing.