THERMOPHYSICAL PROPERTIES OF BUTYL RUBBER LOADED WITH DIFFERENT TYPES OF CARBON-BLACK

The thermal properties (thermal conductivity lambda, thermal diffusivity a, and specific heat capacity C-p) of butyl rubber with 100 phr of different carbon blacks (HAF, GPF, SRF and LAMP black) were measured in the temperature range 300-450 K. The thermal properties were slightly affected by the addition of the different carbon blacks, and there was a sharp increase in both lambda and C-p with temperature on addition of 20 phr of powdered BaTiO3 ceramic only for samples containing SRF and HAF carbon blacks. The electrical conductivity, sigma, was also measured for these composites. It increased appreciably with the surface area of the added carbon black. On addition of 20 phr of powdered BaTiO3 ceramic, the electrical conductivity was observed to increase for all the butyl rubber composites.