ELECTRICAL AND DIELECTRIC-PROPERTIES OF SEGREGATED CARBON-BLACK POLYETHYLENE SYSTEMS

The electrical and dielectric properties of compression‐molded segregated polyethylene‐carbon black mixtures are described in the frequency range between 10 and 8000 kHz as a function of frequency, temperature, and carbon black loading. The segregated systems investigated exhibit insulator‐conductor transitions in the range 0.25–0.65% (volume/volume) carbon black. The dielectric constant and the dissipation factor of the conductive samples are relatively very high in the frequency range studied. The dielectric constant increased sharply with the carbon black concentration, and then increased moderately beyond the insulator‐conductor transition. The dissipation factor‐concentration curves for different carbon blacks show maximum values in the vicinity of the critical concentration values. The dielectric properties of these systems are discussed in terms of interfacial Maxwell‐Wagner polarization effects. Copyright © 1990 Society of Plastics Engineers