Effect of water absorption fatigue on mechanical properties of sisal textile-reinforced composites

Woven sisal textile fiber-reinforced composites are used to evaluate tensile and fracture toughness properties. All specimens are produced that were repeated water absorption on 5 times in this study. The specimens are immersed in pure water during 9 days at room temperature, and dried in 1 day at 50 degrees C. Two kinds of polymer matrices such as epoxy and vinyl-ester are used. Fractured surfaces are taken to study the failure mechanism and fiber/matrix interfacial adhesion. It is shown that it can be enhanced to improve their mechanical performance to reveal the relationship between fracture toughness and water absorption fatigue according to different polymer matrices. Water uptake of the epoxy composites was found to increase with cyclic times. Mechanical properties are dramatically affected by the water absorption cycles. Water-saturated samples present poor mechanical properties such as lower values of maximum strength and extreme elongation. The K-IC values demonstrate a decrease in inclination with increasing cyclic times of wetting and drying for the epoxy and vinyl-ester composites. (c) 2006 Elsevier Ltd. All rights reserved.