Design of ternary solid lubricants SiO2/Ti3C2/PTFE for wear-resistant, self-lubricating polyimide composites

Polyimide is widely used in aerospace, electronics and electrical appliances, automotive, chemical and other fields due to its high temperature stability, excellent mechanical properties. However, polymer materials are often subjected to severe wear and tear under complex operating conditions due to their poor lubrication performance. Therefore, the improvement of lubrication performance is a key strategy to extend the service life of polyimide. Herein, a ternary solid lubricant SiO2/Ti3C2/PTFE (STP) is innovatively prepared by solution dispersion for reducing the friction of polyimide to increase the lubricity. Specifically, SiO2 and PTFE are intercalated accordion-like Ti3C2 nanosheets, thereby causing the nanosheets to slide relative to each other under external frictional stress. Then, STP was introduced into polyimide to prepare the ultra-wear-resistant and self-lubricating composites by blending. The results of the study showed that the STP significantly enhanced the lubrication properties of the composites, the lowest coefficient of friction (0.29) of the composites is 22.81 % lower than that of the polyimide. In addition, the inclusion of hybrids helps to form a transfer film, which effectively improves the abrasion performance of polyimide, and the lowest wear rate (0.18 × 10−5 mm3/(N·m)) was 93.35 % lower than that of polyimide.