Effect of silicone on dynamic mechanical properties of epoxy resin filled with imide powder

Abstraet-The dynamic mechanical properties of epoxy resin and epoxy-silicone alloy filled with thermoplastic polyimide powder have been studied over a temperature range of -150 to 250°C at the frequencies of 35 and 110 Hz and related to the morphological structure of composites observed by scanning electron microscopy. The incorporation of polyimide raised the glass transition temperature (Tg) of both epoxy resin and epoxy-silicone alloy. The storage modulus (E') of composites increased with increasing volume fraction of imide powder. E' of epoxy-silicone alloy composites was higher than that of epoxy resin though the silicone had a low storage modulus. This fact was explained by assuming that below Tg, the presence of silicone in the matrix facilitated molecular rearrangement during cooling from the cure temperature and above Tg, increased the interaction between filler particles and the matrix.