The European Physical Journal Applied Physics (EPJ AP)

DOI: 10.1051/epjap:1998212

Eur. Phys. J. AP 3, 127-134

Relaxation phenomenon in composite materials

R. El. Moznine - F. Blanc - M. Lieutier - A. Lefort

Laboratoires Arc Électrique et Plasmas Thermiques, 24 avenue des Landais, 63177 Aubière Cedex, France

Received: 27 October 1997 / Revised: 28 April 1998 / Accepted: 29 April 1998

Abstract
Dielectric measurement characteristics such as the dissipation factor, relative permittivity and conductivity as a function of temperature and frequency have been achieved on composite materials based on different epoxy resins filled with alumina inclusions. The analysis of the results show the presence of porosity and inhomogeneity in these materials. The study of the dissipation factor, as a function of temperature at high frequencies, has shown an unexpected absorption phenomenon in materials designed to be utilized as electrical insulators. The identification of the entities responsible for this relaxation shows that the entities result from one of the components of the material. These results can also confirm the inhomogeneity of the materials.

PACS
81.05.Qk Reinforced polymers and polymer-based composites - 81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials - 81.05.Rm Porous materials; granular materials

Author for correspondance: spectro@laept.univ-bpclermont.fr