Carbon fibre reinforced bisphenol-A type SPEEK composite for water lubricated superlubricity

Polyether ether ketone (PEEK), as a high-performance engineering polymer, can be a promising material for water lubricated bearings. However, some modifications are imperative when it is widely employed in engineering. In this study, a novel bisphenol-A (BPA) type sulfonated polyether ether ketone (SPEEK-BPA) polymer was synthesized, and it was compounded with 10 wt% carbon fibre (SPEEK-BPA/10 %CF) to obtain a water lubricated material with ultralow friction coefficient (COF) and excellent wear resistance. The outstanding tribological properties of SPEEK-BPA/10 %CF was attributed to the adsorption of hydrated Na+ cations by –SO3¯ and the reinforcement of carbon fibre. The COF of SPEEK-BPA/10 %CF can be reduced as low as 0.009 when a 3 wt% NaCl solution was used as the lubricant at a low sliding speed (0.10 m/s). At the same time, the wear rate of SPEEK-BPA/10 %CF reached to a magnitude of 10-7 and 10-8 mm3/(Nm), which was much lower than commercial PEEK. Therefore, this friction-reducing and anti-wear composite has great potential to realize a water lubricated bearing with low noise and superlubricity.