Tribological Behavior of Ultra‐High Molecular Weight Polyethylene (UHMWPE) With Different Molecular Weights Under Artificial Seawater Lubrication

ABSTRACT Ultra‐high molecular weight polyethylene (UHMWPE), a polymer with significant beneficial properties, exhibits variable characteristics based on its molecular weight. Despite its pivotal role in various applications, research into the tribological behavior of UHMWPE in seawater environments, particularly as it pertains to molecular weight, remains scarce. This study presents an investigation into the tribological behavior of UHMWPE under artificial seawater environments, with a focus on the effects of molecular weight, load, and sliding speed. The results indicated that under artificial seawater lubrication, the friction coefficient and wear volume of UHMWPE increase with the sliding speed, while the wear rate decreases. Additionally, an increase in load results in a reduced friction coefficient but higher wear volume and rate. With an increase in molecular weight, the friction coefficient of UHMWPE initially increased and then decreased, whereas the wear rate initially decreased and then increased. Notably, UHMWPE with medium molecular weights (3.0 × 10 6 and 5.0 × 10 6  g/mol) exhibited superior wear resistance in artificial seawater environments. This study elucidates the complex interplay between molecular weight and tribological performance in UHMWPE under seawater lubrication, providing valuable insights for its application in marine environments.