MWCNTs对环氧树脂及多尺度MWCNTs-碳纤维/环氧树脂复合材料力学性能的影响

Effect of MWCNTs on mechanical properties of epoxy and multiscale MWCNTs-carbon fiber/epoxy composites

通过对胺基化多壁碳纳米管(MWCNTs—NH2)进行改性,得到改性MWCNTs悬浮液(MWCNTs—NH2(M))。分别将羧基化MWCNTs(MWCNTs—COOH)和MWCNTs—NH2(M)分散在环氧树脂(EP)中,采用热熔法制备了多尺度MWCNTs-碳纤维(CF)/EP复合材料。研究了MWCNTs对EP模量、韧性及EP与CF之间界面黏结强度的影响,并分析了MWCNTs与CF上浆剂的作用,评价了多尺度MWCNTs-CF/EP复合材料的力学性能。结果表明:官能团化的MWCNTs可对EP的模量和韧性起到更好的增强作用。MWCNTs接枝的—COOH或—NH2可与CF上浆剂中的环氧基团发生化学反应,提高EP与CF之间的界面剪切强度。MWCNTs—NH2(M)对多尺度MWCNTs-CF/EP复合材料力学性能的增强效果优于MWCNTs—COOH,当MWCNTs—NH2(M)的含量为1wt%时,多尺度复合材料的0°压缩强度、90°压缩强度、弯曲强度、弯曲模量、冲击后压缩强度(CAI)分别提高了16.7%、16.3%、40.9%、30.3%、20.6%。

Modified multi-walled carbon nanotubes suspension（MWCNTs—NH2（M））was prepared by modifying on MWCNTs—NH2.MWCNTs—COOH and MWCNTs—NH2（M）were dispersed in epoxy（EP）respectively,multiscale MWCNTs-carbon fiber/EP（MWCNTs-CF/EP）composites were successfully manufactured by hot-melt method.The effect of MWCNTs on modulus,toughness of EP and interfacial shear strength（IFSS）between EP and CF was investigated,the reactions between MWCNTs and the sizing agent of CF were analysed,and the mechanical properties of multiscale MWCNTs-CF/EP composites were evaluated.The results indicate that functional MWCNTs can strengthen modulus and toughness of EP more effectively.The IFSSs are improved due to the chemical reactions between—COOH or—NH2 grafted on the MWCNTs surface and the epoxy group in the sizing agent of CF.The multiscale MWCNTs-CF/EP composites show an improved mechanical behavior and this effect is more evident with MWCNTs—NH2（M）compared to MWCNTs—COOH,the 0°compressive strength,90°compressive strength,flexural strength,flexural modulus,compression strength after impact（CAI）of multiscale MWCNTs-CF/EP composites can be enhanced by 16.7%,16.3%,40.9%,30.3%,20.6%,respectively when the mass fraction of MWCNTs—NH2（M）is 1 wt%.