Effects of SiO2 nanofiller on the properties of epoxy resin based syntactic foam

This paper focuses on the behavior of syntactic foam consisting of hollow glass microspheres embedded in an epoxy resin matrix. The hollow microspheres have wall thicknesses of 1 μm and a mean diameter of about 45 μm. Inserting microspheres in pure epoxy resin results in an increased viscosity of the liquid material during manufacturing process. In order to counteract this effect, SiO₂ nanofillers are mixed to the liquid, uncured epoxy resin during the manufacturing process before the hollow microspheres are added. Viscosity measurements verify a significant reduction of the mixing viscosity up to 64 % by adding a small weight percentage (<; 5 wt.%) of nanofillers. Furthermore, the impact of the SiO₂ nanofiller on the electrical, mechanical and thermal properties of syntactic foam is determined and discussed.