Dynamic Bleeding Behavior of Commercial Oil-Impregnated Porous Polymers

This study compared the tribological performance of four commercial oil-impregnated porous polymer materials and proposed a new benchmark test to measure their dynamic oil bleeding rate. Results were further evaluated using a half-life model. To reveal the structure-performance relationship, the effects of material properties, surface roughness and porosity on the water contact angle (WCA) were discussed using a combined model based on the Wenzel and Cassie-Baxter equations. Results showed that higher WCAs indicated higher oil content at the interface, which favors better tribological performance. The material with a highly fibrous pore structure demonstrated the best performance, with low friction and temperature as well as the longest half-life. It is suggested that optimizing the fibrous content and pore size can improve the performance and extend the life of oil-impregnated porous polymer. This research provides valuable insights into the evaluation and design of oil-impregnated porous polymer materials for improved tribological performance in various applications.