Cure studies on bifunctional epoxy matrices using a domestic microwave oven

Three types of bifunctional epoxy-amine matrix systems (two room temperature (RT) cure types and one elevated temperature (ET) cure type), used for aerospace composite applications, were cured in a domestic microwave oven. Microwave cure schedules equivalent to vendor-specified thermal cure schedules were evolved for each resin system, using the glass transition temperature (Tg) as the index of cure completion. Both continuous and pulsed microwave heating modes were employed. The cure status and cure uniformity were assessed using differential scanning calorimetry (DSC) and thermal imaging techniques. The studies showed that pulsed microwave-heated samples exhibited greater degree and uniformity of cure (both in terms of temperature attained and the Tg shown across the samples), compared to the continuous microwave-heated samples for all the resin systems studied.