Forming method, crystallinity, and mechanical performance of buckypaper/carbon fiber/polyether ether ketone multi-scale thermoplastic composites

Carbon fiber/polyether ether ketone thermoplastic composites formed by automated fiber placement are susceptible to delamination damage. The interlaminar mechanical performance of carbon fiber/polyether ether ketone laminates can be enhanced in situ by doping carbon nanotubes in the plies. In this paper, the interfacial bonding energy between polyether ether ketone and buckypaper is analyzed by molecular dynamics. A novel method for preparing buckypaper/polyether ether ketone reinforcement materials and buckypaper/carbon fiber/polyether ether ketone multi-scale thermoplastic composites is proposed. The microstructure, crystallinity, and mechanical properties are analyzed. The results show that the polyether ether ketone resin fully penetrate the buckypaper interior and have a good interfacial bonding property. The buckypaper/polyether ether ketone composite films have a dense structure and are well-doped into the plies of carbon fiber/polyether ether ketone laminates. Compared with carbon fiber/polyether ether ketone laminates, the crystallinity, interlaminar shear strength, Model-I fracture toughness, and Model-II fracture toughness of buckypaper/carbon fiber/polyether ether ketone laminates are increased by 22.3%, 22.2%, 20%, and 9.5%, respectively.