Characterization of Fracture Toughness Properties of Coir Fibre Reinforced Polypropylene Composites

This study investigates the production and assessment of fracture toughness in Polypropylene (PP) composites reinforced with different weight fractions of treated and untreated coconut coir fibres. The potential of natural fibres, especially those obtained from agricultural waste like coconut coir, to create lightweight, affordable, and environmentally friendly composite materials has drawn attention. In the study, coir fibres were cleaned and chemically treated with NaOH before being incorporated into PP using injection moulding and extrusion techniques. According to ASTM guidelines, composites with 10%, 20%, and 30% coir fibre concentrations underwent Single Edge Notched Bend (SENB) testing to determine their fracture toughness. The fracture toughness of composites containing 10% and 20% untreated coir fibres was found to be higher than that of pure PP, but composites containing 30% untreated and all treated coir fibres showed reduced fracture toughness. The best composite, with 20% untreated coir, showed the best mix of fibre content and material performance, emphasizing how chemical treatment hurt fibre brittleness and the composites' overall ability to support loads. The potential of untreated natural fibres to improve composite materials for industrial applications- particularly in the automotive industry- is highlighted by this study.