Dielectric Relaxation in a Fluoroelastomer and Ethylene Propylene Diene Monomer Observed by Using Impedance Spectroscopy

Abstract

The dielectric permittivity in polymers, fluoroelastomers and ethylene propylene diene monomers was measured as a function of both frequency and temperature. Several relaxation processes were revealed and analyzed through a developed algorithm to analyze the relaxation. The beta and the alpha relaxations were observed and occurred in that order as the temperature was increased. Maxwell-Wagner-Sillars contributions, including conduction, were present at high temperatures and low frequencies. The molecular chains responsible for the relaxation processes were assigned by using molecular modeling with the dipole moment included. The activation energy, Vogel-Fulcher temperature and glass transition temperature were also obtained.