Comparative study of chemical treatments on the mechanical and moisture absorption behavior of coccinia indica fiber-reinforced epoxy composites

Abstract

Rising demand for eco-conscious-based functional material drives the focus of materials science field scientists towards research on natural fiber-reinforced polymer composites (NFRPCs), which hold significant attention due to their high strength-to-weight ratio and sustainability. For further enhancement, composites are reinforced with surface-treated fibers, which exhibit optimal performance. This work focuses on fabricating epoxy composites reinforced with Coccinia indica fiber. Different surface-treating chemicals were utilised to determine the optimal chemical and its concentration to obtain effective mechanical and water absorption properties of the composite. Results revealed that Coccinia indica fiber-reinforced epoxy composite reinforced with 0.5% of KMnO 4 showed superior performance with a tensile strength of 40.13 MPa and a flexural strength of 89.74 MPa. The compression strength and impact strength of this composite were recorded as 50 MPa and 650 J/m, respectively. By comparison, the untreated CIF/epoxy composite exhibited a tensile strength of 34.59 MPa, flexural strength of 66.63 MPa, compressive strength of 34.4 MPa, and impact strength of 386.7 J/m. The failure mechanism of the fractured samples was determined by employing SEM analysis. Hydrophilic characteristics were determined through the water absorption process, revealing the lowest water intake percentage for this composite, indicating the effective function of KMnO 4 in bonding between the matrix and reinforcement. These findings suggest Coccinia indica fiber-reinforced epoxy composite reinforced with 0.5% of KMnO 4 as a viable alternative to conventional materials, offering a balanced combination of performance, cost-effectiveness, and environmental advantage for semi-structural and automobile applications.