Thermal conductivity of some rubbers under pressure by the transient hot-wire method

Abstract

The transient hot‐wire method was used to determine the effect of fillers on the thermal conductivities of different rubbers in the pressure range up to 0.2 GPa at 300 K. The fillers, carbon black and ZnO, both strongly increase the absolute conductivity values but the relative pressure reponses are only slightly affected. The thermal conductivities increase linearly with pressure, and the pressure coefficients are in the range 1.0–1.6 per GPa for all the rubbers studied. The thermal conductivity of a filled rubber is analyzed in terms of contributions from the filler and the pure rubber. The experimental results show a stronger increase in conductivity with the percentage of filler than predicted by theory.