WEIGHT CHANGES OF A RANDOMLY ORIENTATED GRP PANEL IN HOT-WATER

This paper deals with the weight change mechanism in randomly orientated E glass fibre mat reinforced unsaturated polyester (GRP) panels immersed in hot water. GRP panels were immersed in distilled water at 60-degrees-C and 80-degrees-C, after which the wet and re-dried specimen weights were measured. In this case, the weight change mechanism was divided into three phases. In the first phase, water absorption occurred in the resin matrix, while matrix dissolution with negligible water absorption occurred in the second phase. In the third phase, once again water absorption with continual dissolution of fibre/matrix interface ensued. The delay time for matrix dissolution and water absorption was defined as the difference between the saturation time for GRP and unreinforced resin.