Dielectric Properties of Polyethylene/TiO_2 Composites

摘要

The frequency dependences in the range of 25-10~6 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 TiO_2 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 TiO_2 content in the composite of more than 20%. At high frequencies >2 × 10~3 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 TiO_2 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% TiO_2, 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.