碳纳米管膜层间改性碳纤维/双马来酰亚胺复合材料的结构调控及性能

The interlayer structure adjusting methods were studied on carbon fiber (CF)/bismaleimide composite materials, conducted respectively by thermoplastic interlaminar toughening and carbon nanotube (CNT) film hybridizing in contrast. The changes of compression properties, dynamic mechanical properties, electrical conductivities and electromagnetic shielding properties of the modified CF composites were analyzed. The results show that thermal compaction processing reduces the thickness of the CNT film significantly, suppressing the local resin-rich of the interlayer CNT region. The compressive strengths of the CNT film-CF hybrid composites are improved, with the fracture morphologies obviously different from that of the CF composites. In comparison, the thermoplastic interlaminar toughened CF composites show much lower compression strengths than the CNT film/CF hybrid composites. Additionally, the interlaminar electrical conductive paths are penetrated by the CNT networks of the hybrid composites, hence the thickness direction conductivities are increased by 3 orders of magnitude. However, the volumetric electrical conductivities of the diverse hybrid composites exhibit an evident "Cannikin Law". It is noteworthy that the CNT film interlaminar hybrid can dramatically improve the electromagnetic shielding properties of the CF composite, reaching up to 90 dB for the dense CNT film hybrid composite.