Self-Lubricating Properties of Polyether-Ether-Ketone Composites Filled with CNTs@RC2540 Nano-Capsules

Polyether-ether-ketone (PEEK) exhibits great potential in being a replacement for metal components across various applications relying on the mechanical and tribological properties. However, there is still much to be done to improve its properties. The main motivation of this paper is to improve the tribological and mechanical properties of PEEK simultaneously for more severe working environment. Therefore, dialkyl pentasulfide (RC2540) was proposed to fill into the cavity of CNTs to prepare nano-capsules, which were then filled into PEEK to prepare PEEK/nano-capsules composites. The existence of nano-capsules in PEEK was analyzed, and the friction and wear properties exhibited by PEEK composites against GCr15 steel were examined using pin-disk friction pairs, and the self-lubricating mechanism of PEEK composites in friction was revealed. Findings of this study indicated that when the mass fraction of nano-capsules was less than 5%, the filling of nano-capsules could improve the tensile strength of PEEK and reduced the friction coefficient and specific wear rate of PEEK by filling nano-capsules. During the friction process, RC2540 in the nano-capsules can be released as PEEK wears so that a self-lubricating layer can be formed for reducing PEEK composites' friction and wear.