Degradation of compressive properties of pultruded kenaf fiber reinforced composites after immersion in various solutions

In this paper, water absorption behavior of pultruded kenaf fiber reinforced unsaturated polyester composites was investigated. Residual compressive properties of the composites after immersion were also reported. Composites were prepared using pultrusion method with minimum kenaf fiber content of 70% w/w. Water absorption tests were performed at room temperature under three different solutions, i.e. distilled water, sea water and acidic solution. The diffusion coefficient of water absorption and maximum moisture content were calculated by measuring the water uptake of specimen at regular time interval. Diffusion coefficient and the highest moisture content values were recorded for composite immersed in distilled water followed by acidic solution and sea water. The water absorption of kenaf fiber reinforced unsaturated polyester composites was found to follow a Fickian’s behavior where it reach equilibrium. The compressive properties were found to decrease with the increase in the percentage of water uptake. The decay in compression properties is attributed to the plasticization of the fiber–matrix interface and swelling of the kenaf fiber.