The effect of self-assembly modified potassium titanate whiskers on the friction and wear behaviors of PEEK composites

Potassium titanate whiskers (PTWs) were modified with n-octadecyltrichlorosilane (OTS) by self-assembled method and polytetrafluoroethylene (PTFE)/polyetheretherketone (PEEK) composites were fabricated with either pristine PTW or OTS modified PTW. Tribological and mechanical properties of PTFE/PEEK composites with both fillers were comparatively studied. Results show that OTS was successfully self-assembled on the surface of PTW, which introduces a dramatic increase of water contact angle from 5.5° to 141°. The dispersion of PTW and interfacial compatibility between PTW and PTFE/PEEK matrix were improved owing to the reduction of surface energy of PTW with OTS surface modification, which are the main reasons for the improvements of mechanical and tribological properties of PTW(OTS)/PTFE/PEEK composites. The best wear resistance of PEEK composites was achieved with the addition of 10 wt.% OTS treated PTW, which is 150% higher than the unfilled ones. Water contact angle, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry and differential scanning calorimetry were used in this work for better understanding of the reinforcing mechanisms in both mechanical and tribological properties.