Improvement in the thermal conductivity of particulate-filled epoxy composite

Abstract

Two approaches to improve thermal conductivity of epoxy composite are considered in this work. One is the approach to form a conductive network and the other approach is the improvement in interfacial adhesion between matrix and filler by surface modification of filler. According to the first approach, the effects of different types and particle sizes of metal oxide on the thermal conductivity of metal oxide-filled epoxy composite is studied. The SEM micrographs of the fractured surface show improvement in particle dispersion of nano-size metal oxide particles resulting in an increase in thermal conductivity of composite. The effect of mixing conditions of the BN -filled epoxy composite is investigated. The thermal conductivity f BN -filled epoxy composite can be enhanced with increases in mixing speed, time and temperature. A maximum thermal conductivity of 1.68 W /m K is obtained at 37 vol% filler content and the mixing conditions of 300 rpm , 30 min, 30c. Furthermore, surface modifications of BN with different methods: conventional silane treatment, admicellar polymerization and surfactant treatment are also investigated. The thermal conductivity of BN-filled epoxy composite is significantly enhanced by admicellar polymerization and surfactant treatment. The mechanical properties of the composite also improve significantly.