Friction and wear tests of polymers

Coefficients of friction in the range 0.13–0.63 and specific wear rates in the range 5 × 10 −16 − 2.1 × 10 −14 m 3 N −1 m −1 were measured with a pin-on-disc friction tribometer and a multipin-on-cylinder wear tribometer for 22 commercially available polymer materials. Low friction and wear were measured for the polytetrafluoroethylenes and the polyethylenes. The use of fillers like graphite, MoS 2 and glass did not always improve the tribological properties of the polymers and for some polymers their influence was even the opposite. A decrease in the ambient temperature to −35°C had, for most polymers, the effect of decreasing the coefficients of friction and the wear rates. A remarkable time dependence that extended for the first 68 h of the running-in was registered for the ultrahigh molecular weight polyethylenes plus MoS 2.