Preparation And Characterisation Of Epoxy/Kenaf/Mwcnts Hybrid Composites

This research is to prepare and characterize epoxy/kenaf single-composites and MWCNTs filled epoxy/kenaf multi-scale hybrid composites for the resulted mechanical, thermal, physical and morphological properties. The composites are prepared by using a high speed mechanical stirring process with curing by the solution casting technique. At the first phase of this research, the parameter interaction study and optimization between kenaf fibre content (-5.00 wt. %; +35.00 wt. %), stirring time (-10.00 minutes; +50.00 minutes) and stirring speed (-100 rpm; +700 rpm) for epoxy/kenaf composite system was established by using two-level full factorial design. A set of 23 fractional factorial design for three independent variables, with three replication at centre point and no blocks was used to yield a total of eleven (11) sets of experiments. The Design Expert 6.0.8 software was used to optimize the stirring parameters and kenaf filler loading towards the maximum tensile strength (TS) response. The optimum stirring conditions was optimized into stirring speed at 100 rpm, stirring time at 10 minutes and 5 wt. % of kenaf filler content, with the highest repeatabilityR2 value of ~99.9%. The stage two of this research had specifically focus on the effect of MWCNTs nanofiller weight percentages addition into the epoxy/kenaf composites at 0.00, 0.25, 0.50, 0.75, 1.00 and 3.00 wt. %.The addition of MWCNTs as second reinforcement phase in epoxy/kenaf composites could enhanced the interfacial adhesion and provided good synergistic effects toward the properties enhancement for the epoxy/kenaf/MWCNTs hybrid composites. The multi-scale hybrid composites with 1.00 wt. % of MWCNTs addition, shows outstanding mechanical properties improvement (tensile strength: +48.24% and tensile modulus: +44.59%) as compared than epoxy/kenaf composite (controlled sample).The experimental results were supported with thermal and dynamic analyses. Addition of 1.00 wt.% MWCNTs into epoxy/kenaf composite have shifted glass transition temperature (Tg) at 43.90°C from 41.90°C for epoxy/kenaf composite without MWCNTs. This indicates the role of MWCNTs in improving thermal stability of the hybrid composite. In overall, MWCNTs filled epoxy/kenaf multi-scale hybrid composite, prepared by using an optimized stirring conditions and kenaf fibre loadings was able to provide hybrid synergism between both fillers and the epoxy matrix. Hence, contributed to significant improvement in hybrid composite stiffening effect

Influence Of MWCNTs Addition On Mechanical And Thermal Behavior Of Epoxy/Kenaf Multi-Scale Nanocomposite

This research was conducted to develop kenaf reinforced epoxy/MWCNTs multi-scale composite using kenaf fibre and MWCNTs as the reinforcement in epoxy as the hosted matrix. The composites were produced by using a combination of hand lay-up and vacuum bagging process. The selection of optimum composition of epoxy-MWCNTs is based on the MWCNTs loading and the resulted mixture viscosity. Lower resin viscosity is required to allow good wetting and interaction between matrix and filler, which will yielded superior final performance of the fabricated composites. Therefore, different loading of MWCNTs (0.0 wt. %, 0.5 wt. %, 1.0 wt. %, 3.0 wt. %, 5.0 wt. %, 7.0 wt. %) were used to investigate the mechanical and thermal properties of the composites. As a result, the epoxy/kenaf/MWCNTs multi-scale composite at 1.0 wt. % of MWCNTs addition had yielded substantial improvement by 15.54 % in tensile strength and 90.54 % in fracture toughness. Besides, the fracture surface morphology of the selected samples were analysed via scanning electron microscopy (SEM) observation to further support the reinforcement characteristic of epoxy/kenaf/MWCNTs multi-scale composite

Process Parameter Interaction Study For Epoxy/Kenaf Composites Preparation Via Two-Level Full Factorial Approach

This study was conducted to understand the interaction involved between the process parameters of the solution mixing for the preparation of epoxy/kenaf composites via two-level full factorial approach. There are three (3) independent variables which are the kenaf fibre loadings (-5.00 wt.%; +35.00 wt.%), stirring period (-10.00 mins; +50.00 mins) and the stirring speed (-100 rpm; +700 rpm), involved in this work. A set of 23 full factorial design with three replications at a center point and no block was applied to yield a total of 11 set of experiments. The DesignExpert 6.0.8 statistical software has optimized the resulted tensile strength (TS) response as dependent variable of prepared epoxy/kenaf composites. It was found that the optimum processing parameter are at 100 rpm of stirring speed, 10 mins of the stirring period and about 5.00 wt.% of the kenaf fiber loading, with the highest coeficient of determination R 2 value of 99.9%. Fracture surface morphological observation via SEM has been performed to correlate further the interaction between the processing variables toward an optimum resulted TS response. In overall, this study has significance to facilitate manual processing of natural fiber based epoxy composite started at the early integration between the kenaf fiber as reinforcement phase and epoxy as the matrix phase, using a high speed mechanical stirrer apparatu