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%, ∼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. • BNs/CNT hybrid fillers were embedded into each other and assembled on 3D melamine foam through electrostatic self-assembly to form interconnect thermal paths at macro and micro scales. • Highly thermal conductivity of EP-M(BNs/CNT)x was obtained at exceeding low BNs/CNT additions.