Effect of Recycling on Mechanical Behaviours of Coconut-HDPE Biocomposite

The recyclability of Coconut fibre-HDPE composite makes them an appealing alternative to other non-recyclable composite like glass fibre composite. The aim for this research is to study the ability of the Coconut-HDPE biocomposite (10.00%, 13.75%, 17.50%, 21.25% and 25.00% by weight) to be recycled. Firstly, the mechanical properties of the biocomposite were evaluated and the result shows that Coconut-HDPE biocomposite is superior to Oil palm empty fruit bunch/ Polyurethane (PU) and Rice husk/ Polyethylene glycol. For recyclability testing, the biocomposite has undergone particle recycling process and the properties of the recycled biocomposite are analysed and compared. The research shows that the composite is still able to maintain its tensile strength and even increase its tensile modulus after recycled. For Flexural property, the recycled composite result shows increment in both flexural strength and flexural modulus as well. In order to analyse the reasons behind these increment of mechanical properties after recycled, thermal property study (DSC test), SEM study and chemical study (CHNS test) are done. The thermal test shows that the recycled biocomposite has higher degree of crystallinity with higher fusion enthalpy value. The SEM analysis shows that the recycled biocomposite has more homogeneous and even distribution of coconut fibre among the biocomposite. The CHNS test shows that the Carbon percentage of the biocomposite increased after being recycled. The increase of degree of crystalinity, more homogeneous structure and increase in Carbon percentage are the reasons for the increment of mechanical properties of the Coconut-HDPE biocomposite after being recycled. In short, the property retention and improvement after recycled indicates the promising recyclability of Coconut fibre-HDPE composite.