Dielectric properties of the ethylene butylacrylate/carbon black nanocomposites

In this paper we report the d.c. electrical conductivity measurements between 80 and 350 K, and the dielectric properties at low frequencies (10 Hz < f < 100 kHz) at constant temperature T = 300 K, of the ethylene butylacrylate/carbon black nanocomposites, with different concentrations of the dispersed conducting particles. The concentration of the conductive inclusions has been proved to be a crucial parameter, governing the electrical behavior of these nanocomposites. Above the critical percolation concentration, that is 12% of conducting particles, the Cole-Cole model of dielectric relaxation can be used to interpret the obtained data. The calculated relaxation parameters of the model show that, with the increasing concentration of carbon black nanoparticles, the system becomes more heterogeneous, which is confirmed by the broader distribution of the relaxation times. (C) 2009 Elsevier B.V. All rights reserved.