Hydrogel microcapsules enhanced PEEK composites for advanced water lubrication

Water-lubricated bearings working at low velocity and high contact pressures face critical tribological challenges, especially the thinning and failure of the hydrodynamic water film leads to the direct contact of surface asperities, resulting in severe wear and friction noise. To solve these issues, this study designs an innovative hydrogel-microencapsulated polyether ether ketone (PEEK) composite through the combination of hydrogel microcapsules into the PEEK matrix. This water lubricated composite achieves a 64 % reduction in the coefficient of friction and a one-order-of-magnitude decrease in the wear rate, significantly enhancing the polymer's lubrication performance under severe operating conditions. The mechanism behind the lubrication enhanced performance is attributed to the in-situ formation of hydrogel lubricating films on the PEEK surface. This work proposes an innovative ‘rupture-grow’ lubricating strategy for developing polymer-based bearing materials to address critical tribological challenges.