Tribological Properties of Polytetrafluoroethylene Improved by Incorporation of Fluorinated Graphene with Various Fluorine/Carbon Ratios Under Dry Sliding Condition

Fluorinated graphene (FG) with various fluorine/carbon (F/C) ratios and graphene (G) employed as additions were incorporated into the polytetrafluoroethylene (PTFE) matrix aiming to improve the tribological properties of this self-lubricating polymer. The friction coefficients and wear rates of PTFE-based composites were tested under dry sliding condition using a ball-on-disc configuration. The performances of self-lubricity and wear resistance for four fabricated FG/PTFE composites were superior to those of G/PTFE composite, attributable to the specific surface area and chemical composition of FG sheets with various F/C ratios. Among them, the FG/PTFE composite with filler (F/C ≈ 0.5) loading of 5 wt% exhibited the best tribological property, i.e., the lowest friction coefficient (0.131) and the smallest steady-state wear rate (9.20 × 10 –16 m 3 /Nm). This can be attributed to the formation of uniform and complete transfer film on the friction interface via the tribochemical reactions. Graphic Abstract