Thermal conductivity improvement of epoxy composite filled with expanded graphite

Abstract

The introduction of highly thermally conductive expanded graphite in polymers can functionally improve the thermal conductivity of epoxy resins. In this study, expanded graphite particles were thus introduced into an epoxy polymer matrix via solution blending method with ultrasonic procedure in order to improve the thermal conductivity of the epoxy matrix. The thermal conductivity of epoxy composites was analyzed by laser flash method. The dispersive status of the fillers was characterized by scanning electron microscope (SEM). The thermal stability of the composites was investigated through Thermo-gravimetric analysis (TGA). The results show that the thermal conductivity of epoxy resins increases significantly due to the addition of EG(expanded graphite) particles. As a matter of fact, the thermal conductivity of epoxy composites increases with the increase of EG particles loading from 0wt% to 4.5wt%. The distribution of EG particles in the matrix greatly affects the thermal conductivities of epoxy composites. The thermal conductivity of (KH550@EG)/epoxy composites is greatly improved compared with untreated EG/epoxy composites. The thermal conductivity value of the composites at 4.5wt% loading obtained by experiment is 1.0W/(mK) with a thermal decomposition temperature improved to 348°C from 318°C of pure epoxy.