The gas phase SiO2/epoxy nanocomposites with enhanced mechanical and thermal properties

Abstract

The mechanical and thermal properties of epoxy nanocomposites filled with 7–40 nm spherical silica particles were investigated as a function of silica loadings. Due to the ultrasonic dispersion and modification of the coupling agent, the silicon dioxide (SiO2) nanoparticles were readily dispersed in the epoxy resin with light aggregation for the loading of up to 5 wt% as determined using a scanning electron microscope (SEM). The tensile test indicated that the tensile strength and elongation at break of the nanocomposites increased by up to 23% and 31%, respectively, compared with the neat epoxy resin. The glass transition temperatures of all the epoxy nanocomposites were higher than that of the neat epoxy resin for about 35–45°C, but did not show significant changes with an increase in the silica loading. The fracture surfaces were also observed using SEM, which showed evidence of the SiO2 nanoparticle debonding.