碳纳米管/共聚酰亚胺复合膜增强炭纤维/环氧树脂复合材料的层间断裂韧性和导热性

Increasing the interlaminar fracture toughness and thermal conductivity of carbon fiber/epoxy composites interleaved with carbon nanotube/polyimide composite films

炭纤维/环氧树脂复合材料已被广泛用作航空航天领域的结构材料,但由于其沿厚度方向缺乏炭纤维增强材料,层间力学性能和面外导热性较差。本文制备了碳纳米管/共聚酰亚胺(CNT/BOH)复合膜作为增韧层,以提高炭纤维/环氧树脂层压板的层间断裂韧性和厚度方向导热性。由于BOH膜的塑性变形和CNTs的增强效应,CNT/BOH膜的引入使炭纤维/环氧树脂层压板的Ⅰ型和Ⅱ型层间断裂韧性分别提高260%和220%,此外,由于CNTs高的本征导热性和交联网络的形成,有效改善了层压板的厚度方向导热性。这种增韧方法为同时提高炭纤维/环氧复合材料的力学性能和导热性提供了一种有效的策略。

Carbon fiber/epoxy(CF/EP)composites are widely used in the aerospace industry,but their interlaminar properties and out-of-plane thermal conductivity are poor because of the lack of CF reinforcement in the interlaminar area.We prepared carbon nanotube/polyimide(CNT/PI)composite films and used them to improve the interlaminar fracture toughness(ILFT)and thermal conductivity of laminates of CF/EP and CNT/PI.Interleaving CNT/PI films with unidirectional CF/EP prepregs increased the mode I(the pre-cracked laminate failure is governed by peel forces)and mode II(the crack is propagated by shear stresses)ILFT of CF/EP laminates by 260%and 220%,respectively,which is attributed to the reinforcement effect of the CNTs and the plastic deformation of PI film.In addition,the out-of-plane thermal conductivity of the laminates is improved by introducing CNT/PI films because of their intrinsic high thermal conductivity and the continuous conductive network of CNTs.This toughening method provides an effective strategy for improving the thermal conductivity and mechanical properties of CF/EP laminates simultaneously.