低温等离子体刻蚀和接枝对芳纶纤维/环氧复合材料力学性能的影响

Effect of low temperature plasma etching and grafting on mechanical properties of aramid/epoxy composites

芳纶纤维增强型复合材料在电气绝缘领域应用前景广阔,但芳纶纤维和树脂相容性差,制约了产品性能。为改善界面性能,采用等离子体刻蚀法和等离子体接枝法改性芳纶表面,研究两种方法对芳纶纤维本体、芳纶纤维/环氧复合材料界面性能和其NOL环力学性能的影响。结果表明:两种方法都提升了芳纶纤维/环氧复合材料界面剪切强度。等离子体刻蚀法降低了NOL环拉伸强度,而等离子体接枝法提升了拉伸强度。与改性前相比,采用90 W空气常压介质阻挡放电等离子体处理、1%2,4-甲苯二异氰酸酯接枝后,芳纶纤维/环氧复合材料界面剪切强度由31.7 MPa提升至36.4 MPa,拉伸破坏载荷由23.6 kN提升至25.1 kN,拉伸强度修正系数从62.8%提升至72.1%,芳纶纤维的力学性能得到更加充分的利用。

The aramid fiber(AF) reinforced composite has a wide application prospect in the field of electrical insulation,but the product performance is restricted by the poor adhesion between AF and resin matrix.In order to improve their interfacial performance,the plasma etching method and plasma grafting method were used to modify the AF surface.The influence of two methods on the interfacial properties of aramid fibers and AF/epoxy composites,as well as the mechanical properties of the AF/epoxy composites NOL ring were studied.The results show that both two methods improve the shear strength of the AF/epoxy interface.The plasma etching method reduces the tensile strength of the NOL rings,while the plasma grafting method increases the tensile strength of the NOL rings.Compared with the unmodified AF,the shear strength of the AF/epoxy interface which treated with 90 W air dielectric barrier discharge plasma followed by 1% 2,4-toluene diisocyanate increases from 31.7 MPa to 36.4 MPa,the tensile strength increases from 23.6 kN to 25.1 kN,and the correction coefficient K value of tensile strength increases from 62.8% to 72.1%,indicating that the mechanical properties of aramid fiber are made full use.