Effect of water absorption on the mechanical properties of glass/polyester composites

Laminates were developed by glass fibre fabric and unsaturated polyester. The fabrication was conducted by using the VARI (Vacuum Assisted Resin Injection) technique. The effect of water immersion on the tensile strength and bending behaviour of the composites was experimentally investigated. After immersed in water at a temperature of about 30 °C for various periods, the composites experienced significant reduction of the tensile strength, meanwhile the bending behaviour was improved. These are attributed to the function of the water molecules penetrated in the composites. The failure mode of the samples was shown.