Abstract
We have measured thermal diffusivity of a polyethylene composite filled with copper particles, by a laser flash method, and discussed on the effect of d/l (diameter of particle/sample thickness) on the thermal diffusivity. In the case that d/l is less than 0.3-0.4, the thermal diffusivity can be considered as an effective thermal diffusivity. The d/l (=0.3-0.4) value corresponds to the value of d/l (=0.3), at which CVF value in the electric conductivity of the polyethylene composite begins to decrease. The thermal conductivity was calculated from the thermal diffusivity measured by the laser flash method. The calculated conductivity was found to agree with the thermal conductivity which was measured by another method (steady state and comparison method). Further, our equation was found to be most excellently adaptable to the thermal conductivity of the polyethylene composites.
