Electrical conductivity and positron annihilation characteristics of ternary silicone rubber/carbon black/TiB2 nanocomposites

Abstract The effect of TiB 2 nano-powder content on the electrical conductivity and positron annihilation characteristics of ternary silicone rubber/CB/TiB 2 nanocomposites was studied. The endothermic enthalpy of melting (ΔH m ) and melting temperature of the composites (T m ) were determined by differential scanning calorimetery (DSC). The addition of 12 phr TiB 2 leads to a maximum shift in T m toward higher temperature. Also, χ c values of the investigated composites were found to decrease with increasing TiB 2 content. The dc conductivity has reached maxima in the region of 12 phr TiB 2 followed by a decrease with increasing TiB 2 content. The temperature dependence of the conductivity showed peaks at certain temperatures and shifted to higher temperature with increasing TiB 2 content up to 12 phr. Two types of free volume cavities were detected by positron annihilation lifetime, ranging from V 1 (8.77–18.18 A 3 ) and V 2 (270.68–274.48 A 3 ). A correlation between positron annihilation parameters was also used to discuss the properties of the investigated composites.