IFIR   05409
INSTITUTO DE FISICA DE ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Structure changes in EPDM subjected to ageing in High Voltage Transmission Lines
Autor/es:
P. A. SORICHETTI; C. L. MATTEO; O. A. LAMBRI; G. C. MANGUZZI; L. M. SALVATIERRA; O. HERRERO
Revista:
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
Editorial:
IEEE
Referencias:
Año: 2007 vol. 14 p. 1170 - 1182
ISSN:
1070-9878
Resumen:
This work presents a study of the structural changes in aged EPDM (ethylenepropylene-
diene monomer) from outdoor high voltage transmission lines. Samples were
taken from failed and non-failed insulators after up to ten years in service on a 33 kV
line. Infrared absorption, hydrophobicity index, dynamical mechanical analysis (DMA)
and dielectric relaxation (DR) were employed as experimental techniques. The same
experimental techniques were also applied to new samples of EPDM that were
subjected to high electric fields (up to 14 kV/mm) for several hours. Results from DMA
and DR techniques are in good agreement and, together with previous results from
neutron irradiation techniques, suggest that the experimental data obtained from
outdoor-aged and laboratory tested samples may be explained by a decrease in the
degree of crystallinity due to the interaction between electrical and mechanical effects
in the dielectric. The proposed model is based on the disentanglement of the crystallites
by forces originated in the interaction of the electric field with the polar groups located
in the amorphous phase of the polymer matrix. An alternative explanation, based on a
relaxation process appearing at the interfaces between the filler (ATH) and the polymer
matrix conflicts with several experimental results presented in this work.