The Effect of Crosslinks on the Sliding Wear of High-Density Polyethylene

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

TRIBOLOGY LETTERS

SPRINGER/PLENUM PUBLISHERS

Lugar: New York; Año: 2016 vol. 64 p. 1 - 12

1023-8883

The purpose of this study was to determinate theinfluence of the molecular crosslinking in the wear resistanceof a linear polyethylene (PE) sliding against a roughsteel surface. A set of PEs with different degrees ofcrosslinks were obtained by chemical modification of a PEwith varying concentrations of organic peroxide. Theamount of gel, molecular weight between crosslinks (Mc),crystallinity and Vickers microhardness were determinedin the crosslinked PE?s. The tribological performance ofthe materials was evaluated under dry sliding conditionsusing a block-on-ring tester. The coefficient of friction andthe wear rate were determined in experiments in which asample of polymer was contacted with the peripheral surfaceof a steel ring rotating at constant velocity. The wearresistance of the crosslinked materials increases with theamount of gel and when Mc decreases. The crosslinked PEshowed a wear rate lower than the original PE when theamount of gel was larger than 80 % of the total mass. Thecoefficient of friction of the PE and crosslinked materialwas about 0.2 regardless of the normal load applied. Theanalysis of the worn surfaces by optical and SEM microscopyreveals that the primary mechanism involved in wearis abrasive wear.