Performance Enhancement of Sisal Fiber Epoxy Composites Using <scp> TiO ₂ </scp> and <scp>CuO</scp> Fillers

Abstract

The increasing demand for lightweight, biodegradable, and environmentally sustainable materials in diverse industrial applications has significantly driven interest in polymer composites reinforced with natural fibers and filler particles. This paper investigates the effect of titanium dioxide (TiO 2 ) and copper oxide (CuO) filler particles on the mechanical and water resistance properties of unidirectional sisal fiber reinforced epoxy composite. The incorporation of both fillers (1%, 1.5%, and 2% by weight) enhances the tensile, flexural, short beam shear strength, and water resistance of the composite. The composite specimen was fabricated using the hand lay‐up method, and all tests were conducted following ASTM standards. It was found that the addition of both filler particles up to 2% composition improved the mechanical and water resistance properties, increasing the values of flexural strength by 51.29% and 54.83%, and tensile strength by 5.9% and 4.42% for 2% CuO and TiO 2 , respectively. The highest short beam shear strength was found to be 8.11 MPa for 2% CuO and 9.01 MPa for 1% TiO 2 . The addition of TiO 2 and CuO filler particles also increases the water resistance capacity. Scanning electron microscopic analysis (SEM) demonstrated that the improved fiber–matrix bonding increased the load‐carrying capability and reduced failure susceptibility. XRD and FTIR analyses further confirmed the semi‐crystalline nature of the composites and physical interfacial interactions between the nanoparticles and the fiber–matrix system, supporting the observed mechanical and water resistance improvements.