Electrical conductivity studies on carbon black loaded ethylene butylacrylate polymer composites

In this work we studied the electrical properties of carbon black mixed into ethylene butylacrylate copolymer, using impedance spectroscopy, in the frequency range from 100 Hz to 100 kHz and over the temperature range from 150 to 360 K. A series of samples was prepared with several filler contents, below and above the percolation threshold, which was calculated using direct current conductivity measurements. For concentrations below the critical concentration the negative temperature coefficient in resistivity effect is observed, and for concentrations above that threshold the positive temperature coefficient in resistivity effect is present. The dielectric response was analyzed using complex permittivity or modulus formalisms, depending on the concentration of filler in the polymer matrix. Havriliak–Negami model was used to fit the experimental results.