Dielectric Properties of Polyethylene/TiO2 Composites

Abstract

The frequency dependences in the range of 25–106 Hz of dielectric properties (real and imaginary parts of complex dielectric permittivity and electric modulus) of composite materials based on high-density polyethylene and dispersed filler TiO2 are studied. It is shown that the real part of the complex dielectric permittivity e of composites increases with decreasing frequency. The magnitude of the effect increases with an increase in the TiO2 content in the composite of more than 20%. At high frequencies >2 × 103 Hz, the value of e of composites is practically independent of frequency. The frequency dependences of the electric modulus M—the inverse complex dielectric permittivity—are determined. In composites with a TiO2 content of up to 20%, the imaginary part of the electric modulus M' decreases with increasing frequency, and in composites containing from 20 to 50% TiO2, the opposite effect of decreasing M at low frequencies is observed. On the frequency dependences of all dielectric characteristics, there are no peaks indicative of possible mechanisms of dielectric relaxation associated with molecular mobility.