Polymer composites containing plasma‐treated mica. II. Dielectric properties

Abstract

AbstractThe complex relative premittivity K*(ω) of polymer–mica composites has been studied in the frequency range extending from about 10−2 to 107 Hz. Microwave plasma treatment in ethylene of the mica flakes leads to significant alterations of K*(ω) for the matrix polymers used—polyethylene, polystyrene, and a mixture of these two polymers. The origins of the dispersion characteristics were investigated using a series of polyethylene samples containing up to 50 wt‐% of untreated mica. Comparing experimental results with theoretical analyses of the Maxwell‐Wagner‐Debye‐like interfacial polarization effect, it is possible to identify two major contributions to K*(ω): a Debye‐like dispersion centered near 102 Hz and a charge‐diffusion mechanism which contributes primarily at low frequencies (≲10 Hz).