Characterisation and properties of kenaf fibre / epoxy composite via Organosolv pulping / Mona Rita Othman

Natural fibre is a long-lasting material, yet it has limitations that limit its usage. As a result, by adopting a practical treatment, this research enhanced the conventional fibre treatments that are tedious and high energy consumption. This study was carried out by treating the raw kenaf fibres by using Organosolv treatment. Acetic and formic acids were used as the solvent in the treatment. The duration of fibre being treated was varied at 15, 30, 60 and 90 minutes. Bast and core fibre were used for this study. The characteristics and the tensile properties of the fibres were analysed. Next, study on epoxy was carried out. Epoxy was diluted with acetone at 1:1.25, 1:1.50, 1:1.75 and 1:2.0 and their viscosity was analysed. Tensile properties and weight uptake of single kenaf fibre wetted with the epoxy solution was also studied. Finally, kenaf/epoxy composite was prepared. Three different types of hardener were used namely boron trifluorohydride, N,N-dimethylethyldiamine and diethylenetriamine. The ratio of kenaf pulp fibre to epoxy was varied at volume ratio of 1:4, 1:5 and 1:6. Controlled samples were also prepared without fibre loading. Tensile test, flexural test and impact test were carried out on the composite. Acetic acid was found to produce higher tensile properties kenaf pulp fibre than formic acid. This is due to the characteristics of formic acid which is more corrosive and thus producing fibre with more damage and lower the properties of the fiber itself. For both types of acids, bast fibre showed higher tensile properties. In terms of chemical composition, lignin, cellulose and homocellulose were higher in core fibre for both acids. While ash content and alpha cellulose were higher in core fibre. Epoxy weight uptake of a single fibre was highest at 1:1.5 epoxy to acetone ratio at 15 minutes wetting time; and the highest fibre strength was found at 1:1.75 epoxy to acetone ratio. For the kenaf/epoxy composite, the N,N-dimethylethyldiamine curing system at 1:5 kenaf to epoxy ratio showed the highest tensile, flexural and impact properties, The composite with boron trifluorohydride curing system at 1:4 kenaf to epoxy ratio demonstrated the lowest value in the mechanical properties. Different types of curing system did not impart significantly on density of the composites.