Thermal Diffusivity of Copper/Linear-low-density Polyethylene Composites

The thermal diffusivities of copper/linear-low-density polyethylene (Cu/LLDPE) composites were measured relative to the thermal diffusivity of pure LLDPE. The relative thermal diffusivities were similar to those obtained for copper/high-density polyethylene composites, but were noticeably different from estimated values derived from thermal conductivity, density and specific heat capacity data for Cu/LLDPE from the literature. The thermal diffusivity of the composite material initially decreased below that of the pure polymer with the addition of a small amount of copper, before increasing above it as more was added. There would appear to be marginal or no benefit from adding less than about 15 to 20% metal by volume to a polymer, since the relative increase in thermal diffusivity only becomes significant for greater volumes.