Kenaf fibre-reinforced polyester composites: flexural characterization and statistical analysis

This paper deals with the effect of the chemical treatment, fibre ratio and fibre reinforcement structure on the flexural properties of kenaf-polyester composites. Composites were made from an unsaturated polyester matrix reinforced with an alkali-treated and virgin kenaf fibres in a loose fibres and nonwovens. Results reveal that alkali treatment improves the flexural properties of composites expect elongation. The same result was obtained when using a nonwoven structure us reinforcement. The best flexural properties were observed for 11.1% fibre weight ratio with the nonwoven structure reinforce composite. The flexural strength and the flexural modulus were 69.5MPa and 7.11 GPa, respectively, for this composite while it was 42.24MPa and 3.61, respectively, for polyester samples(no fibre reinforcement). A statistical study was carried out in order to study the effect of the alkali treatment, reinforcement structure and the reinforcement weight ration on the composite properties. This study proved that the parameter with most impact on the measured properties is the fibre-to-matrix weight ratio. And also this study aims to determine the optimum parameters allowing maximising all measured properties and we found that when using a nonwoven structure made with chemically-treated fibre at 11.10% fibre weight ratio, is the optimum solution.