Investigation of the influence of solid lubricants on the tribological properties of polyamide 6 nanocomposite

The tribological properties of nano titanium dioxide filled polyamide 6(TiO2/PA 6 nanocomposite, 5/95 by weight) and its composites filled with single and combined solid lubricants were systematically investigated. It was found that all the solid lubricants except molybdenum disulfide (MoS2) could significantly enhance the tribological performance of TiO2/PA 6 nanocomposite; and the nanocomposite filled with polytetrafluroethylene (PTFE) exhibited lower friction coefficient and wear rate than that filled with ultra-high molecular weight polyethylene (UHMWPE); but it was interesting that the nanocomposite filled with MoS2 combined with UHMWPE had better tribological performance than that filled with MoS2 combined with PTFE, and the nanocomposite filled with MoS2 together with both UHMWPE and PTFE performed the best among the combination solid lubricants. XPS and SEM results showed that the synergism of fillers in helping the formation of thin, uniform and continuous transfer film was responsible for the enhancement in tribological properties.