Abstract

This study investigates the effect of alkali treatment on the physical, thermal, flexural and thermos-mechanical properties of Borassus husk fibre-reinforced epoxy composites according to different authorized standards. Composites were fabricated using the hand layup process with untreated and alkali-treated Borassus fibres (0.25-2 hours treatment duration). The results revealed that alkali treatment significantly improved fibre-matrix adhesion, aided by scanning electron microscopic (SEM) images, leading to enhanced composite performance. The treated fibre composites exhibited lower moisture regain (0.57%-1.28%) and water absorption (0.59%-1.55%) compared to untreated composites, demonstrating improved moisture resistance. Thermal stability increased with alkali treatment, as evidenced by higher integral procedural decomposition temperature (IPDT) values, reaching 547°C for 2-hour treated fibre composites. Additionally, the glass transition temperature (Tg) improved, peaking at 94.5°C for 0.5-hour treated fibre/epoxy. Mechanical properties, including flexural modulus (up to 3.2 GPa) and strength (up to 108.7 MPa), surpassed many conventional bio-fibre composites, making these composites suitable for structural applications compared to existing conventional bio-fibres based composites. Dynamic mechanical analysis indicated superior damping properties (tanδ, up to 1.21), highlighting their enhanced energy dissipation and impact resistance. Among the treated composites, the 0.5-hour alkali-treated Borassus husk fibre/epoxy composite (0.5TBHFE) demonstrated an optimal balance between stiffness and damping, making it a promising material for aerospace and automotive applications. The study underscores the potential of Borassus husk fibres as a sustainable reinforcement alternative in high-performance composite applications. However, further optimization and industrial-scale processing strategies are required to fully harness their potential.