Mechanical Properties of Treated Banana, Sisal and Bamboo Fibre Reinforced Epoxy Composites: A Comparative Study of Single and Hybrid Configurations

Abstract

The increasing demand for lightweight, economical and environmentally sustainable engineering materials has stimulated extensive research into natural fibre-reinforced polymer composites. They are environmentally friendly, fully biodegradable, abundantly available, renewable, cheap and have low density. Hybrids have been shown to perform better than single fibre reinforcements in polymeric matrices. However, natural fibres suffer from some major drawbacks such as high moisture absorption, incompatibility with polymer matrix, and poor mechanical and thermal properties. Therefore, various surface treatments have been employed to modify the surface properties of natural fibres in recent times, reduce the influence of non-cellulosic constituents and improve fibre–matrix interaction. It is in realization of this that tensile and flexural behaviour of water retted banana (Musa sapientum), sisal (Agave sisalana) and bamboo fibre reinforced epoxy composites were investigated. Composite specimens were fabricated under controlled processing conditions, and their mechanical performance was evaluated in terms of tensile and flexural properties. The investigation focuses on the influence of fibre type, reinforcement configuration and hybridization on strength, stiffness and deformation behaviour. The expected improvement in interfacial adhesion following treatment provides a mechanism for more effective stress transfer from the epoxy matrix to the lignocellulosic reinforcement. The comparative approach also enables identification of the fibre combination and configuration offering the most favourable balance between tensile and flexural performance. The tensile strength and modulus for treated single fibre epoxy composite varied in the range of 36-74.34 MPa and 9.6-16.92 GPa, while flexural strength and modulus for treated fibre composites were range of 78-122.31 MPa and 15.7-21.8 GPa. Comparatively the Tensile strength and modulus for treated hybrid composites was in range of 32-87 MPa and 9.7-15.55 GPa while treated hybrid composite have flexural strength and modulus in the range of 78-118 MPa and 21.2-35.7 GPa. Sisal is the most effective single reinforcement for tensile strength and tensile stiffness, while banana provides competitive flexural performance. Among the hybrid systems, sisal–bamboo provides the highest tensile strength and tensile stress at break, whereas banana–sisal provides the most favourable flexural response and the highest flexural modulus. This study contributes to the development of sustainable epoxy-based composites from readily available natural resources and provides experimental evidence for selecting suitable single and hybrid fibre architectures for lightweight, non-load-bearing optoelectronics applications.