Abstract
Bio-based materials are gaining importance in engineering due to their availability, recyclability, and environmental benefits. Among them, the Borassus flabellifer (Palmyra palm) fruit shell husk is an underused biofibre in Bangladesh, typically discarded or used only for low-value applications, despite its potential for high-performance uses. In its untreated form, the husk fibre shows favourable thermal properties: high char content, IPDT, IPDH, and Cp- making it competitive with natural fibres such as jute, ramie, and flax. Alkali treatment removes hemicellulose and further enhances thermal stability, increasing char yield, IPDT, and IPDH, although Cp decreases. Epoxy composites reinforced with alkali-treated fibres demonstrate superior thermal stability compared to neat epoxy and many conventional bio-composites reported in the literature. Dynamic Mechanical Analysis (DMA) indicates higher glass transition temperature (Tg) and increased tan δ (damping factor), reflecting improved fibre–matrix interaction. SEM images confirm enhanced interfacial bonding, contributing to better impact performance. Overall, the results highlight that alkali-treated Borassus husk fibre/epoxy composites are strong candidates for use in engineering structures, including automotive and aerospace components. Their adoption supports sustainable materials development and contributes to achieving global ‘Net-Zero’ goals under the 2015 Paris Agreement.