Tribomechanical Properties of Polymeric Composites Based on Mixture of Ultra High Molecular Weight Polyethylene and Polyamide

摘要

In order to find out optimum filler to increase manufacturability (extrudability) of composites based on ultra-high molecular weight polyethylene (UHMWPE) matrix as well as to develop polymer-polymeric composites with improved tribological characteristics, the structure, mechanical properties and wear resistance of UHMWPE mixtures with elasticizing blockcopolymer PA-b-LLDPE (UHMWPE + PA-b-LLDPE) was investigated under dry sliding friction. Applied aspect of the study is related to the selection of commercially available fillers being compatible with UHMWPE for manufacturing anti-frictional extrudable nanocomposites. It is shown that as compared with pure UHMWPE mechanical properties (ultimate strength, value of elongation at failure) do not vary substantially, but the wear rate under dry sliding friction of polymeric composites UHMWPE + n wt.% PA-b-LLDPE is reduced only when block copolymer weight fraction is less than ≤ 5 wt.%. By the polymeric filling an important technological characteristic - specific pressure of extrusion (that is proportional to melt flow index) might be decreased. Permolecular structure and wear track surfaces of polymer-polymer composites UHMWPE + n wt.% PA-b-LLDPE was examined and numerically characterized.