Water absorption characteristics of polyester matrix composites reinforced with oil palm ash and oil palm fibre

Abstract

The water absorption characteristics of polyester matrix hybrid composites reinforced with oil palm ash and oil palm fiber have been investigated. Open moulding method was used to produce polyester hybrid composites of 2, 4, and 6 wt% reinforcement consisting of oil palm ash (OPA) and oil palm fiber (OPF) in weight ratios of 1:0, 3:1, 1:1, 1:3 and 0:1 respectively. Water immersion test was used to study the adsorption behaviour from which the water diffusion mechanisms of the composites were established. The results show that the amount of water absorbed by the composites increases with increase in the fiber weight ratio of the OPA-OPF hybrid reinforcement and also with the increase in the weight percent of the reinforcement phase. The diffusion transport mechanism as predicted from the diffusion exponent (n) shows that the majority of the hybrid reinforced composite compositions and all the composites reinforced only with OPF exhibited super case II or case II diffusion. But all the composite grades reinforced with OPA only and the unreinforced polyester exhibited Fickian and less Fickian diffusion, respectively. It was only the hybrid composition containing 2 wt% reinforcement having weight ratio OPA: OPF of 3:1 that exhibited the intermediate behavior between Fickian and non-Fickian diffusion. Generally, it is observed that the values of the diffusion exponent (n) increase as the amount of water absorbed by the composites increases. ©2013 Usak University all rights reserved.