Fabrication of a polymer composite with high thermal conductivity based on sintered silicon nitride foam

A novel route was developed to fabricate Si3N4/epoxy composite. In this route, the Si3N4 particles were constructed into the foamed shape by using protein foaming method, firstly. Then the Si3N4 foams were sintered to bond these Si3N4 particles together. Finally, the Si3N4/epoxy composite was fabricated by infiltrating the epoxy resin solution into the sintered Si3N4 foams. This route was proved to be an efficient way in enhancing the thermal conductivity of epoxy matrix at a low loading fraction. For example, the thermal conductivity of the as-prepared Si3N4/epoxy composite with a loading fraction of 22.2 vol% was up to 3.89 W m−1 K−1, which was about 17 times higher than that of neat epoxy.