Influence of filler content, particle size and temperature on thermal diffusivity of polypropylene-iron silicon composites

The filler fraction, particle size and temperature dependence of thermal diffusivity in polypropylene-iron silicon composites were examined by laser flash method. Results show that raising the filler content raises the thermal diffusivity of the composite material only slightly. Nevertheless, the higher the filler content the higher the influence of the filler material expressed by a altered course of the thermal diffusivity versus temperature. Measurement values are compared with selected existing mathematical models whereas a model, originally developed for magnetic permeability, by Hashin and Shtrikman shows the best congruence. Further measurements show that the particle size of the filler does not have an influence on the composite's thermal diffusivity at the examined filler content.