Comparative analysis of effect of nano- and microfillers of oxidated Al on mechanical and tribological properties of UHMWPE
The paper describes the effect of nano- and microfillers, including nanofibers and ultradispersed powder of Al<sub>2</sub>O<sub>3</sub>, on mechanical and tribological properties of ultrahigh molecular weight polyethylene. It is found that its modification by Al<sub>2</sub>O<sub>3</sub> nanofibers in a concentration of 0.1-0.5 wt.% increases considerably its strength and augments manyfold its wear resistance. Modification by ultradispersed Al<sub>2</sub>O<sub>3</sub> powders (200-500 nm) in the same concentration varies slightly the tribological behavior of the polymer. The filling of ultrahigh molecular weight polyethylene with particles of micron size (3-50 μm) in a concentration of 20 wt.% causes increase in the wear resistance of the original polymer that is comparable to the wear resistance at a small concentration of nanofibers. Examination by X-ray structure analysis, IR spectroscopy, and electron microscopy has shown that the introduction of Al<sub>2</sub>O<sub>3</sub> nanofibers into ultrahigh molecular weight polyethylene leads to the formation of a principally new supramolecular structure compared to the use of microfillers