Effect of crosslink on tribological performance of polyurethane bearing material

Polyurethane, as one versatile family of material, has been studied widely for water-lubricated bearings material. However, the connection between tribological performance and their internal material structure, in particular, crosslinks, remains elusive. Here, the effect of crosslink on the tribological performance of thermoplastic polyurethane (TPU) has been elucidated. TPUs with different crosslink degree were obtained by strengthening hydrogen bonded effect via Gamma-ray. The result shows that the friction coefficient increases with the increase of crosslink degree overall. It is because that enhanced crosslink means more molecular chains crosslink together by hydrogen bonds, resulting in more energy consumption during the friction process. In addition, incremental and larger particles produced during friction leads to third-body mechanism, acting on wear behavior of TPU.