Synergetic effect of hybrid boron nitride and multi-walled carbon nanotubes on the thermal conductivity of epoxy composites

[Display omitted] ▶ Functionalized BN and MWCNTs were utilized as fillers to fabricate the epoxy/hybrid filler composites. ▶ The BN and MWCNTs were modified by sol–gel and free radical reaction, respectively. ▶ As compared to pristine fillers, the TC of the composite embedded with functionalized filler was enhanced. ▶ The synergetic effect resulting from hybrid filler was proved by the enhancement of TC of composite containing 10–30 vol% BN and 1 vol% MWCNTs. This study investigates the synergistic effect of combining multi-walled carbon nanotubes (MWCNTs) and boron nitride (BN) flakes on thermally conductive epoxy composite. The surface of the two fillers was functionalized to form covalent bonds between the epoxy and filler, thereby reducing thermal interfacial resistance. The hybrid filler provided significant enhancement of thermal conductivity, adding 30 vol% modified BN and 1 vol% functionalized MWCNTs achieving a 743% increase in thermal conductivity (1.913 W mK −1, compared to 0.2267 W mK −1 of neat epoxy).