Synthesis and dielectric properties of epoxy based nanocomposites

Abstract

Insulation based on epoxy resin is widely used in high voltage applications. This paper shows the formulation of epoxy based nanocomposites and the influence of the filler material on the DC breakdown strength. Filler materials discussed are SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and AlN with average particle size between 22 and 100 nm. AlN has been chosen because it has shown to considerably increase the thermal conductivity of epoxy resin. SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> are widely used as filler for electrical applications since they improve mechanical, thermal and electrical properties, beside neat epoxy samples, which have been used as reference. Base material for all samples is conventional bisphenol-A type epoxy resin with anhydrite hardener. Particle size and dispersion within the epoxy matrix have been validated via transmission electron microscopy. Breakdown measurements have been performed by means of DC ramp tests. Results of nano-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> samples have also been compared with surface functionalized microscale filler.