Mechanical and water absorption properties of resin transfer moulded kenaf fibre reinforced composites

摘要

This investigation focuses on the tensile, flexural, impact and water absorption propertiesudof kenaf fibre reinforced composites manufactured by resin transfer moulding. Varyingudprocessing conditions and resin system are considered as alternatives to fibre treatments,udthereby potentially avoiding additional cost and complexity in the manufacturing process.udTensile, flexural, impact and water absorption tests were conducted. Composites wereudproduced with fibre volume fractions of 15 %, 22.5 % and 30 %. Fibre moisture content,udmould temperature and mould pressure following injection were altered in polyesterudcomposites. Processing conditions were found to have little effect on properties exceptudfor pressurisation which increased tensile and flexural strength and decreased waterudabsorption at low fibre volume fractions. Vinyl ester and epoxy composites wereudcompared to those made using polyester resin. The results revealed that properties wereudaffected in markedly different ways by the resin system and the fibre volume fraction.udPolyester composites show good modulus and impact properties, epoxy compositesuddisplay good strength values and vinyl ester composites exhibit good water absorptionudcharacteristics. Scanning electron microscope studies show that polyester composites failudby fibre pull-out, epoxy composites by fibre fracture and vinyl ester composites by audcombination of the two. Theoretical models were applied to composites made using alludthree resin systems. There was good correlation with measured values of tensile linearudmoduli and flexural strength but poor correlation with measured values of tensileudstrength, tensile secant moduli and flexural secant and linear moduli. A comparisonudbetween kenaf and glass composites revealed that the specific tensile and flexural moduliudare comparable at low fibre volume fractions. However, glass composites have muchudbetter specific properties than the kenaf composites at high fibre volume fractions for alludthree resin systems.