Kenaf fiber mat/polylactic acid biocomposites: effect of chemical treatment on mechanical and physical properties

Research on biobased materials has been increasing worldwide. It combines renewable and sustainable raw reinforcement resources materials and biodegradable matrices for the next generation of bio-composite products. In this research, kenaf fiber mat (KFM) reinforced polylactic acid (PLA) bio-composites have been prepared using the compression moulding technique. To enhance the mechanical and physical properties of the bio-composites, KFM was alkali treated with sodium hydroxide (NaOH). Treatment lasted for 3 hours at concentrations of 2%, 4%, 6%, and 8%. Tensile and water absorption properties of untreated and alkali-treated KFM-PLA bio-composites were compared and studied. FTIR spectroscopy and scanning electron microscopy (SEM) characterizations were also used to evaluate the surface chemistry and morphology of the fibers due to chemical treatment. The study observed that alkali-treated KFM at 6% led to a significant enhancement in tensile and water absorption properties of PLA bio-composites. Morphological studies by SEM proved the relationship between fracture surface and good fiber-matrix interaction, believed to enhance the fiber-matrix interfacial adhesion after chemical treatment. Overall, it can be concluded that the alkali treatment on KFM played an essential role in improving the mechanical and physical properties of KFM-PLA bio-composites.