Dielectric properties obtained from viscoelastic measurements in EPDM

P. A. SORICHETTI; O.A. LAMBRI; C. L. MATTEO; R.R. MOCELLINI; G. I. ZELADA-LAMBRI; J. A. GARCÍA; F. PLAZAOLA; A. L. RODRIGUEZ GARRAZA; J. A. CANO

Buenos Aires

Congreso; Congreso Internacional De Distribución Eléctrica (CIDEL); 2010

Asociación Argentina de Distribución de Energía Eléctrica

A model has been recently reported that describes two-phase polymers at the mesoscopic scale, with polar groups embedded in one of the phases. Low-frequency electrical and mechanical stresses are coupled through the permanent dipole moment of polar groups embedded in one of the phases.     The low-frequency dielectric relaxation is calculated as the superposition of two Debye processes, corresponding to the interaction of the polar groups with the two phases. The parameters of the dielectric relaxation processes are obtained from the electro-rheological model using viscoelastic data from dynamic mechanical analysis. In this work the model is applied to predict the dielectric response in commercial EPDM (ethylene – propylene – diene – M - class rubber) employed as housing in electrical insulators rated at 33 kV, for new and aged samples. In all cases, a good agreement was found between the calculated and measured dielectric spectra, within the low-frequency range where the model is applicable.