Thermal conductivity of micro-and nanostructural epoxy composites at low temperatures

The thermal conductivity of epoxy composites containing not only the traditional fillers quartz, talc, carbon black, and aerosil, but also the very promising carbon nanomaterials is investigated. Two kinds of carbon nanomaterials - multi-wall (MWNT) and single-wall (SWNT) carbon nanotubes - were considered. The influence of their content (from 0.05 to 3.0 wt.%) on the thermal conductivity of MWNT-epoxy composites was studied. The thermal conductivity of epoxy composites was examined in the temperature range from -150 to 150C. It was found that the introduction of 0.1-1.0 wt.% MWNT enhanced the thermal conductivity of pure epoxy resin by about 40%. A further increase in content of the nanotubes decreased the thermal conductivity. This can be explained by the worsening of nanotube dispersion at their high concentrations. The maximum growth in the thermal conductivity of the epoxy composites, on the entire range of temperatures considered, was observed at a 0.1 wt.% content of MWNT.