Abstract
To overcome the disadvantages generated by the loosened nanoparticle agglomerates dispersed in polymer composites, an irradiation grafting method was applied to modify nanosilica by covalently bonding polyacrylamide (PAAM) onto the particles. When the grafted nanosilica was added to epoxy, the curing kinetics of the matrix was accelerated. Moreover, the grafting PAAM can take part in the curing of epoxy so that chemical bonding was established between the nanometer fillers and the matrix. Sliding wear tests of the materials demonstrated that the frictional coefficient and the specific wear rate of nanosilica/epoxy composites are lower than those of the unfilled epoxy. With a rise in nominal load, both frictional coefficient and wear rate of the composites decrease, suggesting a wear mechanism different from that involved in wearing of epoxy. Grafted nanosilica reinforced composites have the lowest frictional property and the highest wear resistance of the examined composites. Compared with the cases of microsized silica and untreated nanosilica, the employment of grafted nanosilica provided the composites with much higher tribological performance enhancement efficiency.