FLEXURAL BEHAVIOUR OF HYBRID EPOXY COMPOSITES REINFORCED BY RAMIE FIBRE AND COFFEE BEAN PARTICULATE

Abstract

Natural fibre polymer composites (NFRC) have always been the focus of researchers due to their excellent properties and advantages. In recent years, environmental concerns have drawn attention to bio-based material composites. Despite extensive research on natural fibre reinforced polymers, the study of their mechanics is still in its infancy. Ramie fibre is a natural fibre that has been continuously tested to explore its great potential because of its excellent mechanical properties. Biodegradable waste, such as coffee bean particulate waste, has high potential for use as polymer reinforcement to improve the properties of composites. Therefore, in this study, the hybrid epoxy composite of ramie fibre and coffee bean particulate aims to enhance flexural behavior. Ramie fibre epoxy composites were fabricated with different fibre orientations of 0°/0° and 0°/90°, as well as different weight fractions of coffee bean powder at 5 wt%, 10 wt%, and 15 wt%. Fabrication was conducted using the VARI method. Three-point bending tests were carried out to evaluate the flexural properties. The results showed that flexural strength was maximized (29.945 MPa) at a fibre orientation of 0°/0° with 10 wt% of coffee bean powder. The fracture mechanism was investigated using scanning electron microscopy (SEM). The analysis revealed that the fibre-matrix interface exhibited defects such as delamination, matrix microcracks, fibre fracture, voids, and fibre pull-out. These failures indicate poor adhesion between the fibres and the matrix.