RELATIONSHIP BETWEEN WEAR AND FRICTION IN CROSSLINKED HIGH DENSITY POLYETHYLENE

ERICA C. MOLINARI; MARCELO D. FAILLA; WALTER R. TUCKART

Workshop; 2º INTERNATIONAL WORKSHOP OF TRIBOLOGY TRIBaires 2013; 2013

The present study investigates the wear behavior of crosslinked high density polyethylene (HDPE) in contact with steel with the aim of knowing the influence of the molecular structure on the wear performance of the material. Materials with different molecular structures were generated by modifying a HDPE with a organic peroxide. The characterization included a solvent extraction method to obtain the gel fraction, swelling measurements to calculate the molecular weight between crosslink, calorimetric measurements to determine the heat of fusion and Vickers microhardness measurements. The tribological properties were evaluated by performing block-on-ring wear tests under well controlled temperature ambient. The wear behavior results show that modified materials with concentrations of peroxide lower than 0.5 wt% have higher wear rate than the unmodified polymer. The materials modified with higher peroxide concentration than that, display a wear rate decreasing with the peroxide concentration, reaching values much lower than the corresponding to the original polymer when the peroxide concentration was largest than 1 wt%.