Effect of radiation on the friction-wear properties of polyetherketone with a cardo group

We studied the effect of radiation on the friction-wear properties of polye therketone with a cardo group (PEK-C) with a MM-200 model friction and wear tester. We found that radiation could improve the friction-wear properties of PEK-C to a certain degree. The friction coefficient and wear rate of PE K-C decreased as the radiation dose increased from 5 X 10(4) to 1 X 10(7) G y. Scanning electron microscopy results revealed that the size of wear debr is of unirradiated PEK-C was larger than that of irradiated PEK-C. The worn surface of unirradiated PEK-C showed plough marks, whereas the worn surfac e of irradiated PEK-C did not show plough marks; its surface was quite smoo th. With the frictional couple of a carbon steel ring and an irradiated PEK -C block, a relatively uniform and coherent transfer film was formed on the ring surface. It was inferred that the transfer film contributed largely t o the decreased friction coefficient and wear rate of the irradiated PEK-C. An IR spectrum showed that no significant chemical change took place when the PEK-C sample was irradiated. Thermal analysis results showed that radia tion changed the thermal properties of PEK-C, therefore, its friction-wear properties changed at the same time. (C) 2001 John Wiley & Sons, Inc.