Thermal Conductivity and Mechanical Properties of Carbon Black Filled Silicone Rubber

Abstract

The effects of two types of carbon blacks (CBs), N990 and Vulcan XC-72, on the mechanical properties and thermal conductivity of filled silicone rubber (SR) were investigated. It was found that the addition of CB particles increased the thermal conductivity, the thermal stability and the tensile strength of the silicone rubber composites. The scanning electron microscope showed that Vulcan XC-72 of higher structure was more liable to form conductive network within the matrix, and the thermal conductivity of the composites filled by Vulcan XC-72 was superior to that of the composites filled by N990 at the same filler loading. The Agari model and the Payne effect were used to explain the influence of N990 and Vulcan XC-72 on the formation of thermal conductive networks. Furthermore, Vulcan XC-72 also had better enhancing effects on the mechanical properties and the electrical conductivity of the composites. It was notable that at the high filler contents, silicone rubber filled with N990 also possessed good general properties.