Enhanced tribological properties of polyimide composite with carbon fiber/graphitic‐carbon nitride nanosheets

Abstract Developing polymer self‐lubricating composites is of great significance for reducing mechanical friction and wear. In this study, a hybrid of graphitic carbon nitride (g‐C 3 N 4 ) nanosheets anchored carbon fiber (CF) was constructed through one‐step calcination method to enhance the tribological performance of polyimide (PI). The presence of g‐C 3 N 4 improved the interfacial interaction of CF/PI composite by endowing CF surface with active sites and rough microstructure. Tribological test results demonstrated that CF/g‐C 3 N 4 /PI composite had outstanding antifriction and wear resistance, with friction coefficient and wear rate of 0.209 and 2.23 × 10 −7 mm 3 /Nm, which were reduced by 21% and 73.52% compared to pure PI, respectively. This was mainly attributed to the enhanced interfacial interaction, which was conducive to the stress transferring from PI to CF/g‐C 3 N 4 in sliding process. At the same time, the g‐C 3 N 4 nanosheets could give the composite excellent self‐lubrication property by promoting the formation of transfer film. More importantly, the as‐proposed CF/g‐C 3 N 4 /PI composite still maintained good self‐lubricating performance in different sliding environment, with a friction coefficient of 0.132 in water environment and 0.049 in oil environment, suggesting it had a broad prospect in polymer self‐lubricating composite. In addition, the corresponding mechanism was discussed based on the analysis of worn surface of the composite and counterpart.