Wear resistant PEEK composites with great mechanical properties and high thermal conductivity synergized with carbon fibers and h‐BN nanosheets

Abstract It is well known that carbon fiber (CF) reinforced PEEK (polyether‐ether‐ketone) (defined as “PEEK/CF”) composites have excellent properties and have been widely used in diverse fields. Meanwhile, hexagonal boron nitride (h‐BN), as an excellent nano reinforcing agent, is often incorporated into polymer to improve its mechanical strength and thermal conductivity. Herein, PEEK matrix was regulated by adding high‐strength CF as the load‐bearing phase and 2D h‐BN sheets as the solid lubricant and thermally conductive fillers prepared by melt blending to achieve the multi‐scale packing of uniform mixing. The results show that h‐BN is well dispersed in PEEK matrix and improves the interfacial bonding between CF and PEEK matrix, exhibiting a good synergistic effect in enhancing tensile properties of composites. PEEK composite with 20 wt% CF and 4 wt% h‐BN (referred as P/20C/4B) exhibits the highest tensile strength (176.05 MPa) and thermal conductivity (0.396 W/(m·K)), which are 97.54% and 126.3% over those of pure PEEK (89.12 MPa; 0.175 W/(m·K)), respectively. In addition, PEEK composite with 10 wt% CF and 4 wt% h‐BN (referred as P/10C/4B) has excellent tribological properties with a friction coefficient of 0.15, the lowest fiction temperature (30.5°C) and a relative low wear rate of 1.62 × 10 −6 mm 3 /(N·m) among them. The synergitic effects of h‐BN and CF on mechanical, tribological properties and thermal conductivity of PEEK composites provides a very broad prospect in their application of low frictional and wear resistant polymeric materials.