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

A novel route was developed to fabricate Si 3 N 4 /epoxy composite. In this route, the Si 3 N 4 particles were constructed into the foamed shape by using protein foaming method, firstly. Then the Si 3 N 4 foams were sintered to bond these Si 3 N 4 particles together. Finally, the Si 3 N 4 /epoxy composite was fabricated by infiltrating the epoxy resin solution into the sintered Si 3 N 4 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 Si 3 N 4 /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.