Microwave Curing of Polyester Resin Based Composite Materials for Nautical Applications

Polyester resins are largely used in the manufacture of fibreglass boats thanks to their high workability and low costs. In this work, a preliminary study on the microwave curing of a polyester resin and the related composite material used in marine industry is presented. Samples of polyester resin with 2% catalyst have been exposed to microwaves in a 2.45 GHz oven, varying exposure time with a power output of 1800 W. After that, laminates (10 cm x 10 cm) made by three layers of fibreglass (MAT 600) and polyester resin have been prepared by manual lay-up and exposed to microwave irradiation in the oven. After the curing, the laminates have been tested by a universal dynamometer in a three points bending test, according to the ASTM D 790 for FRP materials. The results obtained by the microwave curing of the matrix resin demonstrated that the use of high power level and short exposure time, inducing a fast cross-linking, generates residual stress in the cured resin that can cause the matrix cracking. This preliminary study has shown as the microwaves curing of polyester composites can be proposed as a valid alternative method for a faster processing of laminated materials for structural applications