Effect of carbon fiber surface modification on the flexural mechanical properties of carbon fiber reinforced polyetheretherketone biocomposites

Carbon fiber (CF) reinforced polyetheretherketone (PEEK) is one of the most promising orthopedic implant biomaterials. In this paper, CF reinforced PEEK biocomposites were fabricated by hot press molding technology. The influence of the CF surface modification on the flexural mechanical properties of CF/PEEK biocomposites was investigated. Studies on the flexural mechanical properties of CF/PEEK biocomposites revealed that the flexural stress-strain behavior of the biocomposites possessed linear elastic characteristics. The fracture mechanism of the biocomposites was predominated by brittle rupture. Both flexural strength and modulus of the biocomposites obviously increased with the rise of CF content. The influence degree of different CF modification on the flexural properties of CF/PEEK biocomposites increased with the rise of CF content. Moreover, the CF modified by concentrated HNO3 is beneficial for the flexural strength of the CF/PEEK biocomposites improvement. Conversely, CF modified by KH-560 coupling agent played an adverse influence on the flexural strength of the biocomposites.