LiCl处理对芳纶纤维表面结构与性能的影响

为提高芳纶纤维与复合材料基体间的界面强度,首先,使用LiCl乙醇溶液处理芳纶纤维一定时间;然后,对LiCl处理芳纶纤维表面的化学组成、微观形貌、单丝拉伸强度及芳纶纤维/环氧树脂复合材料的界面性能等进行了测试分析。结果表明:使用LiCl乙醇溶液处理芳纶纤维后,芳纶纤维表面的含氮官能团含量增加;处理后,芳纶纤维表面有刻蚀出的沟槽,表面粗糙度增大,进而改善了芳纶纤维与环氧树脂基体的界面粘接性能,使芳纶纤维/环氧树脂复合材料的层间剪切强度由处理前的21.75 MPa提升到37.98 MPa;最佳处理时间为3~4h,而处理时间过长会导致芳纶纤维的单丝拉伸强度及复合材料的层间剪切强度下降。所得结论证实使用LiCl处理芳纶纤维是一种有效的表面改性方法。

Effects of LiCl treatment on surface structure and properties of Kevlar fibers

In order to improve the interfacial strength between Kevlar fibers and composite matrix, LiCl ethanol solution was used to treat Kevlar fibers by certain time. Then, the surface chemical composition, micromorphology, tensile strength of single filament for LiCl treated Kevlar fibers and interface properties of Kevlar fibers/epoxy resin composites etc. were tested and analyzed. The results show that after using LiCl ethanol solution treating Kevlar fibers, the content of nitrogen containing functional groups on Kevlar fiber surface increases. After the treatment, there are some etched grooves appear on the Kevlar fiber surface and the surface roughness increases, thus the adhesion property between Kevlar fibers and epoxy resin matrix enhances, which makes the interlaminar shear strength of Kevlar fibers/epoxy resin composites increases from 21.75 MPa before treatment to 37.98 MPa. The optimum treatment time is 3-4 h, while the unnecessary extend of treatment time will lead to the decrease for the tensile strength of single filament for Kevlar fiber and the interlaminar shear strength of composites. The conclusions obtained proves that using LiCl to treat Kevlar fibers is an effective method for surface modification.