基于碳纳米管薄膜的复合材料层间增韧

通过浮动催化化学气相沉积法制备连续碳纳米管薄膜，并将其原位沉积到单向碳纤维织物表面，手工铺层后借助真空辅助树脂传递模塑成型（VARTM）工艺制备碳纳米管-碳纤维/环氧树脂复合材料层压板，研究不同面密度的碳纳米管薄膜对层压板Ⅱ型层间断裂韧性的影响。结果表明，随着碳纳米管薄膜面密度的增加，层压板Ⅱ型层间断裂韧性先逐渐提高，当碳纳米管薄膜面密度为9.64 g/m²时，层压板Ⅱ型层间断裂韧性最佳，与原始层压板相比提高了94%。碳纳米管通过桥接树脂裂纹、从树脂中拔出等方式提高层间断裂韧性。当碳纳米管面密度超过临界值时，会引起树脂浸润困难，导致增韧效果降低。

Toughness enhancement for interlaminar fracture composite based on carbon nanotube films

To enhance the interlaminar toughness of laminated composites, the continuous Carbon NanoTube (CNT) film made by the floating catalyst chemical vapor deposition method is in-situ deposited on the surface of unidirectional carbon fiber fabrics. The CNT film interleaved carbon fiber/epoxy laminated composites are then fabricated by using the Vacuum Assisted Resin Transfer Molding (VARTM) processing. The effect of the areal density of the CNT film on the mode II fracture toughness of these hybrid composites is analyzed. The testing results indicated that mode Ⅱ fracture toughness initially increased gradually with the increase of the areal density of the CNT film. When the areal density of the CNT film is about 9.64 g/m², mode Ⅱ fracture toughness of the laminate increased by 94% compared with that without the CNT film interleaving. Microcrack bridging by CNTs and CNT pulling-out from the resin are found to be the main mechanisms of toughening. Upon further increasing the areal density of CNT films, mode Ⅱ fracture toughness deceased, which is mainly due to fact that CNT films might not be fully wetted by the resin as they are getting thicker.