Enhancement of Epoxy Composites with Benzoylated Fibres of Demostachya bipinnata (Darbha): Impact on Mechanical Properties

Benzoylation treatment represents a promising strategy to enhance adhesion between plant fibres and polymer matrices. This study aims to improve the properties of epoxy composites using benzoylated fibres of Demostachya bipinnata (Darbha). The analysis focuses on the impact of chemical treatment on the physicochemical and mechanical characteristics of the fibres and resulting composites. After retting and alkaline pre-treatment of the fibres, benzoylation using 10 wt% concentrated benzyl chloride is applied to introduce benzene groups, thereby enhancing the density and chemical stability of the fibres. Results highlight increased density (1869 kg.m-3) and enriched crystalline cellulose composition in benzoylated fibres (BDE) compared to untreated fibres (UDE). FTIR analysis confirms significant structural modifications with the introduction of additional carbonyl and carboxyl groups, reinforcing essential interfacial bonds. Mechanical tests reveal 30% higher tensile and flexural strength for epoxy/BDE composites compared to epoxy/UDE composites, demonstrating the effec-tiveness of benzoylation in improving mechanical properties. Thermal analysis also shows improved thermal stability of BDE fibres, crucial for demanding industrial applications. In summary, this study demonstrates significant enhancement in performance of benzoylated Darbha fibres as composite reinforcements, opening new avenues for their use in sectors such as automotive and construction, where high mechanical strength is crucial.