Synergetic effect of thermal conductive properties of epoxy composites containing functionalized multi-walled carbon nanotubes and aluminum nitride

This study investigates the thermal conductivity of epoxy composites containing two hybrid fillers which are multi-walled carbon nanotubes (MWCNTs) and aluminum nitride (AlN). To form a covalent bonds between the fillers and the epoxy resin, poly(glycidyl methacrylate) (PGMA) were grafted onto the surface of nano-sized MWCNTs via free radical polymerization and micro-sized AlN was modified by zirconate coupling agent. Results show that functionalized fillers improve thermal conductivity of epoxy composites, due to the good dispersion and interfacial adhesion, which is confirmed by scanning electron microscope. Furthermore, the hybrid fillers provide synergetic effect on heat conductive networks. The thermal conductivity of epoxy composites containing 25 vol.% modified AlN and 1 vol.% functionalized MWCNTs is 1.21 W/mK, comparable to that of epoxy composites containing 50 vol.% untreated AlN (1.25 W/mK), which can reduce the half quantity of AlN filler used. (C) 2011 Elsevier Ltd. All rights reserved.