MWCNTs对碳纤维非褶皱无纺布/环氧层合板力学性能的影响

Effect of MWCNTs on mechanical properties of carbon fiber non-crimp fabric/epoxy laminates

将羧基化多壁碳纳米管(MWCNTs)添加到TDE85环氧树脂中,然后与碳纤维非褶皱无纺布(C-NCF)复合,制备成[0°/90°/+45°/-45°]S层合板。采用三点弯曲、短梁剪切和单边切口弯曲测试方法以及动态力学性能分析方法,研究了不同含量的MWCNTs对层合板弯曲性能、层间剪切强度(ILSS)、Ⅱ型层间断裂韧性(GⅡC),以及玻璃态转变温度(Tg)的影响。并采用SEM对Ⅱ型试样的断面进行分析。结果表明,MWCNTs的加入显著提高了NCF层合板的力学性能。与空白试样相比,当MWCNTs在树脂中的质量分数为2.0%时,弯曲强度和模量分别提高了约26%和6%;当MWCNTs的质量分数为0.5%时,ILSS、GⅡC、Tg分别提高约14%、27%和14%。

MWCNTs were functionalized with carboxyl and then mixed with epoxy TDE85. The obtained mixtures were used to impregnate the NCF laminates, stacking with a sequence of [-0°/90°/＋ 45°/- 45°]s. Flexural properties, interlaminar shear strength （ILSS）, and mode Ⅱ interlaminar fracture toughness （Guc）, as well as the glass transition temperature （Tg） of the resulting laminates were characterized using three-point bending, short beam shear, end notch flexure （ENF） specimens, and a dynamic mechanical analysis, respectively. SEM was used to analyze the fracture characteristics of the tested ENF specimens. The results show that there are reinforcing effects of the MWCNTs on the mechanical properties when the mass fraction of the MWCNTs varies from 0 to 2.00%. The flexural strength and modulus are improved by 26% and 6%, respectively, with 2.00/60 mass fraction of MWCNTs. The ILSS, Gnc and Tg are enhanced by 14%, 27% and 14%, respectively when 0.5% mass fraction of MWCNTs is used.