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

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

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。

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(0 wt%,2.5 wt%,5.0 wt%and 7.5 wt%)were uniformly dispersed in PMR resin by ultrasonic dispersion.The modeⅠinterlaminar 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 modeⅠinterlaminar fracture toughness of the PMR adhesive layer for Ti-CF/PMR super hybrid laminates is improved by 74%with 5.0 wt%MWCNTs;when 5.0 wt%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.