Inspired by ocean ball buffer pools: Crafting polyurethane elastic nanospheres and their carbon fiber reinforcement potential

Surface modification of carbon fiber (CF) is one of the important technical difficulties in improving the interface performance between CF and epoxy resin, thereby enhancing the performance of carbon fiber composite material. By changing the polarity of the solution, it was easy to achieve the preparation of uniform sized nanoscale spherical particles, and achieved the uniform deposition of a single layer of nanospheres on the surface of carbon fibers, without destroying the original structure and strength of carbon fibers. The polyurethane elastomer nanospheres uniformly distributed on the surface of the modified carbon fibers successfully achieved a new type of elastic interface of carbon fibers and improved the wettability of carbon fibers. Under the mechanism of physical and chemical enhancement, the mechanical properties of the composites were well improved. The results show that the interlaminar shear strength and the tensile strength of single carbon fiber uniformly coated with nanometer polyurethane pellets are increased by 39.68 % and 9.39 %, respectively, compared with the desized CF based composite. The fracture mechanism of the composites under stress was elucidated by the transverse and longitudinal fracture morphology, and the interface theory of carbon fiber reinforced polymers (CFRP) were further developed. Provided innovativeness for the design and development of non-destructive CF surface modification technology and simplified CF surface modification steps.