In-situ fabrication of a UHMWPE nanocomposite reinforced by SiO2 nanospheres and its tribological performance

In-situ fabrication of nanocomposites facilitates the dispersion of nanofillers in organic matrixes by decreasing the agglomeration of nanofillers compared to a mechanical mixing method. UHMWPE nanocomposites filled SiO2 nanospheres (SNS) were in-situ fabricated by a sol-gel method in this work. Their sliding coefficient of friction and wear rate were determined by a high-speed ring-block wear test apparatus against 45# steel under dry friction conditions, and the tribological behaviors at elevated temperature were tested by a slurry abrasion wear configuration. The in-situ filled SiO2 nanospheres presented an excellent dispersion on UHMWPE, and the fabricated SNS/UHMWPE nanocomposites were found a remarkable enhancement in stiffness, glass transition temperature and hydrophobicity. Furthermore, the SNS/UHMWPE nanocomposites exhibited markedly improved tribological performances than the matrix UHMWPE and the referenced sample prepared by a mechanical mixing method: the sliding coefficient of friction was reduced by over 50% than that of the pristine UHMWPE against a 45# steel ring under dry friction, and the mass wear rate was ca. 59% of the UHMWPE matrix determined by a water-bath mortar at an elevated temperature. [Display omitted] •An in-situ fabrication method of nanocomposites is disclosed.•The silica nanospheres were in situ filled into UHMWPE in liquid phase.•The filled silica nanospheres were well dispersed and combined with UHMWPE.•The COF against 45# steel and wear rate in sand slurry were markedly reduced.•The content of aqueous ammonia and the loading of nanofillers were key points.