High-humidity deterioration and internal structure change of epoxy resin for electrical insulation

Abstract

Mechanical and electrical properties of filled epoxy were evaluated by accelerated aging under high humidity and high temperature. Significant changes in these properties arose from the slight water absorption. The presence of internal and irreversible flaws such as microscopic damage probably associated with the elastic inhomogeneities were predicted by scanning laser acoustic microscope attenuation, and surface structure changes were found by mercury porosimetry during the accelerated aging. It is considered that such internal and/or surface flaws play an important role of the changes in various properties due to water absorption.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>