▎ 摘　　要

To make up for the limited mechanical strength of polyurethane (TPU) material, carbon nanotube (CNT) and graphene (G) were added as reinforced phase into TPU matrix. The mechanical property of this CNT-G/TPU nanocomposite as well as its self-healing property under microwave processing were studied. Firstly, the solution mixing method was adopted to prepare the polyurethane nano-composite filled with carbon nanotube and graphene. Then the mechanical property of this G-CNT/TPU nanocomposite was investigated by tensile testing. Mechanics principle analysis and scanning electron microscopy (SEM) were used to study the mechanisms of mechanical enhancement of this material. Secondly, self-healing property of these nanocomposites under microwave electromagnetic fields was also studied through the crack-repair processing, tensile testing and SEM characterization. Moreover, the mechanisms of both mechanical enhancement and self-healing under microwave radiation were studied. The results indicated that, in terms of mechanical properties, there was synergetic reinforcement effect between the graphene and CNT, which could further improve the mechanical performance of G-CNT/TPU nanocomposites when compared with the samples that were only reinforced with CNT or grapheme. With the ratio of graphene to CNT at 3: 1, the mechanical properties of G-CNT/TPU composites reached the optimum value of 70.6 MPa. The tensile strength of G-CNT/TPU composites increased by 67% when compared with that of pure TPU materials, by 18% when compared with that of G/TPU composites, and increased by 25% when compared with that of CNT/TPU composites. In term of the self-healing of cracks in the material under microwave radiation, the results showed that these G-CNT/TPU composites could be healed effectively and rapidly by microwave electromagnetic radiation. Besides, it was shown that the self-healing efficiency could be further improved by the synergy effect between graphene and CNT. With the ratio of graphene to CNT at 3: 1, the self-healing of G-CNT/TPU composite reached the best result, which was about 117% of the virgin composite..