Self-interlocked MXene/polyvinyl alcohol aerogel to enhance flame retardancy, dynamic mechanical properties and electrical conductivity of carbon fibre/epoxy composites

Carbon fiber (CF) reinforced polymer composites (CFRPs) are often damaged by impact, fire and lightning strikes, which limit their wide applications. In this work, the flame retardancy, impact resistance and electrical conductivity of CF reinforced epoxy (EP) composites have been simultaneously improved through the self-interlocked 3D skeleton of Ti₃C₂T_x/polyvinyl alcohol (PVA) aerogel (TPA). The CF/EP and TPA/CF/EP composites have been characterized using Cone tests, split Hopkinson bar tests, and current tests. It is shown that TPA can suppress the release of heat, smoke particles and toxic gases in virtue of heat trapping, catalytic and barrier mechanisms at high temperature. The stitching effect of TPA can effectively limit the delamination failure and promote the absorption of fracture energy. Compared with the CF/EP composites, the Young's modulus of TPA/CF/EP composites has been increased by 22.7% in the range from 1967 s⁻¹–2003 s⁻¹. The crack initiation time of the TPA/CF/EP composites was delayed by about 50%. Moreover, the 3D skeleton of TPA facilitates the formation of current channels within the TPA/CF/EP composites, which enables the overall improvement of the electrical conductivity of the TPA/CF/EP composites in the longitudinal, transverse, and through-thickness directions. Among them, the electrical conductivity increases up to 61% in the through-thickness direction has been attained.