Characterization of epoxy composites reinforced with silane-modified <i>Dracaena reflexa</i> fiber and <i>Citrus medica</i> leaf-derived cellulose particles

This study investigates the mechanical, thermal, moisture absorption, and morphological properties of epoxy composites reinforced with silane-treated Dracaena reflexa microfibers and silane-treated Citrus medica leaf-derived cellulose particles. Hybrid composites were fabricated and evaluated to determine the influence of treated natural reinforcements on overall composite performance. Among the formulations, specimen EMC2 exhibited the most balanced and superior properties. EMC2 achieved a tensile strength of 127 MPa, flexural strength of 141 MPa, impact energy of 3.36 J, and hardness of 83 Shore-D compared with neat epoxy. The composite also showed improved thermal conductivity of 0.37 W/mK and reduced water absorption of 1.54%. These enhancements are attributed to improved fiber-particle-matrix interaction, effective stress transfer, crack deflection mechanisms, and reduced interfacial defects resulting from silane treatment and uniform filler dispersion. Scanning electron microscopy revealed a compact fracture morphology with uniform reinforcement distribution and strong interfacial bonding in EMC2, supporting the observed improvements in mechanical and functional properties. Overall, the results demonstrate that silane-treated natural reinforcements can effectively enhance the performance of epoxy-based hybrid composites, highlighting their potential for sustainable high-performance material applications.