Influence of metallic fillers on the thermal and mechanical behaviour in composites of epoxy matrix

Thermal behaviour and the breaking strength of a liquid epoxy resin (diglycidylether of bisphenol "A", DGEBA) crosslinked with ethylenediamine (ETDA) and filled with various percentages of metallic fillers were analysed. The thermal treatment was carried out by dynamic thermogravimetry in a nitrogen atmosphere over the temperature range 25-500 degrees C and at a constant heating rate of 50 degrees C/min. Samples with and without metallic fillers, and three epoxy-amine molar ratios (1:1, 1:1.5 and 2:1) were selected. The results from thermal studies showed a high influence of the filler on the thermal stability of the epoxy under investigation. The filled materials presented decomposition temperature lower than those of the non-filled materials. The experimental results from the mechanical test showed the highest breaking strength for the 1:1 epoxy-amine ratio without metallic filler, in contrast to those with filler in which the mechanical behaviour depended on filler type and the content of it. (C) 1999 Elsevier Science Ltd. All rights reserved.