Synergistic effect of multiscale BNs/CNT and 3D melamine foam on the thermal conductive of epoxy resin

High heat conduction epoxy resins with a more than twofold increase in thermal conductivity at a low filler addition were fabricated by construction of three-dimensional synergistic thermal conductive networks at macro and micro scales. Shortly, boron nitride nanoplates/carbon nanotubes (BNs/CNT) were embedded into each other and assembled on 3D melamine foam skeletons via electrostatic interaction, prior to addition of epoxy resin. The introduced melamine foam has the characteristics of strong adsorption and ultra-high porosity, which are convenient for BNs/CNT to establish multiscale synergistic heat conduction channels at a microscopic scale. The morphological characteristics of M(BNs/CNT)x were revealed by FESEM and elemental mapping images pointed to continuous BNs/CNT thermal paths forming along the 3D skeleton of the melamine foam within epoxy resin. Consequently, the thermal conductivity of the epoxy resin improved from 0.21 W m(-1) K-1 to 0.43 W m(-1) K-1 at a rather low filler content of BNs/CNT (about 0.43 wt%, similar to 1/1). The epoxy resin further possessed a relatively low dielectric constant (about 7.38 at frequency = 10(7) Hz) as suggested by dielectric characteristic analysis. This presents promising application prospects in the field of electrical insulation materials.