Comparative analysis of the influence of nano- and microfillers of oxidized Al on the frictional-mechanical characteristics of UHMWPE

Abstract

The influence of nano- and microfillers, including nanofibers and powder of Al2O3 and aluminum oxyhydrides AlO(OH) on the mechanical and tribological characteristics of ultrahigh-molecular-weight polyethylene (UHMWPE) is studied. It is found that modification of UHMWPE with nanofibers of Al2O3 within 0.1–0.5 wt % ensures a considerable increase in its hardness and multifold increase in its wear resistance. Modification with ultradisperse powders of Al2O3 (200–500 nm) in the same amounts has an insignificant effect on the polymer characteristics. Filling of UHMWPE with micron-sized particles (3–50 μm) in amounts of 20 wt % results in increased wear resistance of the original polymer, comparable with the wear resistance at low nanofiber content. X-ray diffraction analysis, IR spectroscopy, and electron microscopy are used to show that incorporation of Al2O3 nanofibers into UHMWPE results in the formation of a fundamentally different supermolecular structure in comparison with the use of microfillers.