Dependence of dielectric behavior on the physical property of fillers in the polymer-matrix composites

Low-density polyethylene (LDPE)/electrical conducting fillers composites were prepared via simple blending and hot-molding technique. Dielectric property of the composites with different conductivity fillers, such as carbon fiber (CF), cupper (Cu) and nickel (Ni) powders was investigated. Dependence of the dielectric property of the LDPE/fillers composites on frequency and volume fraction of fillers was studied. The experimental results could be explained by means of the conductivity of fillers and the interface polarization between LDPE and fillers. Percolation was also seen in this study when the volume fraction of conducting fillers was close to critical value, in which the composites undergo an insulator-conductor transition. The relationship among the dielectric property, the microstructure and the fillers with different conductivity was proposed. (C) 2004 Elsevier B.V. All rights reserved.