Test methodEffect of test parameters on degradation of polyurethane elastomer for accelerated life testing

The degradation characteristics of polyurethane (PU) elastomer sliding against stainless steel were investigated using a pin-on-plate reciprocating tribo-tester in terms of the decrease in height of the specimen. From tests lasting for 234 h, which corresponded to a 270 km sliding distance, it was found that the rate of height decrease of the PU specimen ranged from 0.15 μm/km to 0.9 μm/km, mainly caused by compression set and wear. The height decrease rate of the PU specimen increased by a factor of 6 with increasing normal force and temperature while the general degradation characteristics were maintained. It was also shown that the use of discolored lubricant from service further increased the degradation of the PU specimen. Furthermore, signs of abrasive and adhesive wear of the PU elastomer were observed. The results of this work may provide a basis for designing an accelerated life testing method for hydraulic reciprocating seals.