Fabrication of Thermally Stable Polysulfone Microcapsules Containing [EMIm][NTf2] Ionic Liquid for Enhancement of In Situ Self-Lubrication Effect of Epoxy

Microcapsules containing an ionic liquid (IL) are potential candidate materials for preparing in situ self-lubricating composites with.excellent tribological properties. 1-ethyl-3-methylimidazolium bis[(trifluoromethyl) sulfonyl]imide ([EMIm]NTf2) IL encapsulated polysulphone microcapsules are synthesized. The mean diameter and wall thickness are about 128 mu m and 10 mu m, respectively. Microcapsules have excellent thermal stability, with a thermal degradation onset temperature of 440 degrees C compared to traditional lubricants loaded microcapsules. In situ self-lubricating composites are prepared by incorporating the IL-encapsulated microcapsules into epoxy matrix. When the concentration of the IL microcapsules is 20 wt%, the frictional coefficient and specific wear rate of composites are reduced by 66.7% and 64.9% under low sliding velocity and middling applied load conditions, respectively, as compared to the neat epoxy. The tribological behavior of the self-lubricating composites is further assessed in different applied load and sliding velocity conditions. The in situ self-lubricating mechanism of composites is proposed.