Effect of High-frequency Microwave Radiation on the Mechanical Properties of Plantain (Musa paradisiaca) Fibre/Epoxy Biocomposite

Natural fibres were extracted from plantain (Musa paradisiaca) pseudostem and modified using high-frequency microwave irradiation under different conditions in terms of power and time. First, the mechanical and morphology of treated and untreated fibre were investigated. Mechanical (tensile) properties test results reveal that microwave radiation at 550 W power was able to improve the tensile strength and modulus of the fibre. Scanning electron microscope (SEM) analysis shows surface roughness of the fibre has increased and uniform surface roughness was achieved. However, higher power and time of microwave irradiation causes a decrease in the mechanical properties the fibre as SEM image reveals the serious damaging effect on the surface of the fibre, due to degradation and rupturing of fibre cells by the exposure of inner central lumen of the fibre. In the second part, fibre-polymer biocomposite was fabricated using epoxy as the polymer matrix. Tensile and flexural test results reveal an increase in strength at optimised microwave power and time. A decrease in mechanical properties was observed at prolong and higher power radiation. Water absorption of fibre-polymer biocomposite was found to decrease after treatment at lower irradiation, interfacial adhesion of fibre-matrix was shown to increase with surface modification as reveals by SEM micrograph.