Dielectric relaxation behavior of conducting carbon black reinforced ethylene acrylic elastomer vulcanizates

Abstract

ABSTRACT:The dielectric relaxation characteristics of conductive carbon black (CCB) reinforced ethylene acrylic elastomer (AEM) vulcanizates have been studied as a function of frequency (10 1 -10 6 Hz) at different filler loading over a wide range of temperatures (30-120 C). The effect of filler loadings on the dielectric permittivity (e 0 ), loss tangent (tan d), complex impedance (Z*), and electrical conductivity (r ac ) were studied. The variation of e 0 with filler loading has been explained based on the interfacial polarization of the fillers within a heterogeneous system. The effect of filler loading on the imaginary (Z 00 ) and real (Z 0 ) part of Z* were distinctly visible, which may be due to the relaxation dynamics of polymer chains at the polymer-filler interface. The frequency dependency of r ac has been investigated using percolation theory. The phenomenon of percolation in the composites has been discussed in terms of r ac . The percolation threshold (/ crit ) occurred in the range of 20-30 phr (parts per hundred) of filler loading. The effect of temperature on tan d, e 0 , r ac , and Nyquist plots of CCB-based AEM vulcanizates has been investigated. The CCB was uniformly dispersed within the AEM matrix as studied from the transmission electron microscope (TEM) photomicrographs. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: [678][679][680][681][682][683][684][685][686][687][688] 2012

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Increasing the performance of dielectric elastomer actuators: A review from the materials perspective

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