Effects of the media and ageing condition on the tensile properties and fracture toughness of epoxy resin

This paper presents the water diffusion behaviour, tensile properties and fracture toughness of epoxy after it is aged in distilled and salt water in both steady and fluctuating conditions at a temperature of 50 °C. In steady and fluctuating conditions, the equilibrium water uptake of epoxy aged in salt water is lower than that in distilled water, but the diffusion rate is unaffected. The effects of the media and ageing condition on the tensile properties and fracture toughness are insignificant. The absorbed water (0.6-1.8%) improves the epoxy fracture toughness up to three times, which is indicated by the complex fracture surfaces of aged epoxy.