多壁碳纳米管对Ti-碳纤维/反应型聚酰亚胺超混杂层板力学性能的影响

为了改善Ti/反应型聚酰亚胺（PMR）树脂界面的黏结强度，从而提高Ti-碳纤维（CF）/PMR超混杂层板的力学性能，本文探究了添加多壁碳纳米管（MWCNTs）对Ti-CF/PMR超混杂层板力学性能的影响。将不同质量分数（0wt%、2.5wt%、5.0wt%和7.5wt%）的MWCNTs利用超声分散法均匀分散于PMR树脂中，随后进行Ⅰ型断裂韧性试验，探究添加MWCNTs对Ti-CF/PMR超混杂层板界面性能的影响，最后选取最优含量的MWCNTs同时添加到PMR胶层和CF/PMR树脂中，并进行弯曲试验，探究添加MWCNTs对Ti-CF/PMR超混杂层板力学性能的影响。通过SEM观察和分析了相应的失效模式和增强机制。结果表明:当MWCNTs含量为5.0wt%时，Ⅰ型层间断裂韧性提高了74%；同时添加5.0wt% MWCNTs于PMR胶层和CF/PMR复合材料树脂中，Ti-CF/PMR超混杂层板的弯曲性能较未添加MWCNTs提高了42%。这是由于MWCNTs在PMR胶层和CF/PMR树脂中的分布均匀性较高，且能分散并承受界面层转移到纤维层的载荷，并利用自身拔出、断裂、桥接、脱黏来吸收并消耗断裂能量，进一步提升Ti-CF/PMR超混杂层板的弯曲性能。 

Effect of multi-walled carbon nanotubes on mechanical properties of Ti-carbon fiber/polyimide by monomer polymerization super hybrid composite laminates

In order to improve the bonding strength of Ti/polyimide by monomer polymerization (PMR) resin interface and improve the mechanical properties of Ti-carbon fiber(CF)/PMR super hybrid laminates, the effect of the addition of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties of Ti-CF/PMR super hybrid laminates was investigated in this paper. The MWCNTs with different mass fractions (0wt%, 2.5wt%, 5.0wt% and 7.5wt%) were uniformly dispersed in PMR resin by ultrasonic dispersion. The mode Ⅰ interlaminar fracture toughness tests were experimentally conducted to explore the effect of adding MWCNTs on the interface properties of Ti-CF/PMR super hybrid laminates. Then the MWCNTs of optimized content was added to the PMR adhesive layer and CF/PMR resin to conduct bending test so as to explore the effect of adding MWCNTs on the mechanical properties of Ti-CF/PMR super hybrid laminates. SEM was used to investigate the interface morphology and enhancement mechanism of Ti-CF/PMR super hybrid laminates. The results reveal that the mode Ⅰ interlaminar fracture toughness of the PMR adhesive layer for Ti-CF/PMR super hybrid laminates is improved by 74% with 5.0wt% MWCNTs; when 5.0wt% MWCNTs are added into both the PMR adhesive layer and CF/PMR resin, the bending property of Ti-CF/PMR super hybrid laminates is improved by 42% compared with those without adding MWCNTs. This is because the MWCNTs are uniformly dispersed in the PMR adhesive layer and CF/PMR resin, and it can disperse and bear the load transferred from the interface layer to the fiber layer, using its own pull-out, fracture, bridging, debonding to absorb and consume the fracture energy to further improve the bending performance of the Ti-CF/PMR super hybrid laminates.