Ultralow friction of PEEK composites under seawater lubrication

Water-lubricating bearings made of polymer-matrix composites have provided a new approach to prolong the service lifetime of key component in marine propulsion system. However, it was still crucial to find a convenient and effective material to manufacture the water-lubricating bearing with ultralow friction. Herein, a new kind of polyetheretherketone (PEEK) composite with ultralow coefficient of friction (COF), high mechanical strength and thermal stability has been developed. An 80.7% decrease in the COF of PEEK was achieved by incorporating the fillers. A possible mechanism between the heterogeneous nucleation and mobility hindrance of PEEK chain segment caused by different fillers was proposed. The ultralow COF endowed the water-lubricating bearing with low running noise and reduced energy consumption. The high mechanical strength and thermal stability caused the superior carrying capacity and reliability. Therefore, the prepared PEEK composites can be a possibility to realize the water-lubricating bearing with high durability and long service lifetime.