Synthesis and AC Electrical Characterization of Isobutylene Isoprene Rubber Loaded with Carbon Black Fillers

Isobutylene isoprene rubber (IIR) filled with High Abrasion Furnace (HAF) and General Purpose Furnace (GPF) carbon black nano fillers was synthesized and characterized. The fillers were impeded in the rubber matrix with various concentrations (40, 60, 70, 80 and 100 phr), The thermal stability of the synthesized composites was examined by thermogravimetric analysis (TGA). The surface morphology of the samples was analyzed using scanning electron microscopy (SEM). It was observed that the carbon black particles were assembled in aggregates which are randomly distributed among the rubber matrix. The size of the aggregates was greatly influenced by the amount of filler content. The AC electrical conductivity of the composites was investigated as a function of frequency at different temperatures. The frequency-dependent conductivity followed Jonscher’s power law and hence, the frequency exponent was estimated for all samples. Moreover, the correlated barrier hopping model was used to calculate the maximum barrier height. In addition, the frequency- dependent dielectric constant of the rubber/carbon black composites was studied.