OPTIMISATION APPROACH FOR THE CURING PROCESS OF NEAT EPOXY RESIN AND EPOXY MATRIX COMPOSITES USING BOTH THERMAL MICROWAVE ENERGY

摘要

Microwave curing of polymer matrix composites has proven to be an attractive substitute for conventional thermal curing. In order to efficiently utilize this form of energy, precise control over power, temperature, and time were applied to achieve set goals: reduce cure time and thermal overshoots, assure complete cure, and maximize mechanical properties. Test samples consisted of both neat blend of DGEBA resin together with samples of glass fiber reinforced epoxy. Curing experiments for a specific temperature-time profile show that microwave applicator not only follows the set temperature but also eliminates thermal lag and overshoots. Kinetic knowledge is enriched using DSC to determine expected curing times at different curing temperatures. Based on these data, a selected isothermal temperature of 100°C was used with variable dwell times between 13-30 minutes. Mechanical testing data shows that microwave cured samples have slightly exceeded the conventionally cured ones in both flexural strength and modulus. In addition, the DSC approximated cure time of 13 minutes also applies for microwave curing.