Thermal Conductivities of Epoxy Resins Filled with

Graphene and Alumina

Adhesives of high thermal conductivity are required to impart efficient heat dissipation to electronic parts where heats are generated during operations and the functions of the device may be badly affected by the increase of temperature. In order to improve the thermal conductivity of adhesives based on polymer systems, fillers of high thermal concuctivities such as particulates of silver, boron nitride, aluminum nitride, and alumina are usually incorporated.  Recently, graphenes are attracting attentions of scientists due to the excellent electrical and thermal conductivities as well as high mechanical strength.  In this study, we have investigated thermal conductivities epoxy resins filled with hybrids of graphene and alumina. Dispersion of graphene and alumina in diglycidyl ether of bisphenol A based epoxy resin was obtained by ultrasonication at room temperatures. It was observed that the thermal conductivity of epoxy resins filled with hybrids of graphene and alumina were superior to those filled with only graphene or alumina after cure.  It is postulated that the percolation of the graphene-alumina hybrids occurs at lower concentrations  than those of graphenes and alumina in the epoxy resins due to the bridging effects of graphenes between aluminas.

Keywords: thermal conductivity, epoxy resin, alumina, graphene