Enhanced Mechanical, Dynamic Mechanical Analysis, Thermal, and Tribological Properties of Bio Composites Reinforced With Biosilica From Paddy Straw

ABSTRACT This study explores the performance of Roselle fiber‐epoxy composites reinforced with biosilica from Paddy straw, emphasizing the effects of silane treatment on the morphology, mechanical properties, dynamic behavior, thermal degradation, wear resistance, and hydrophobicity. Silane treatment enhanced fiber‐matrix adhesion, as confirmed by Scanning Electron Microscopy and Energy Dispersive X‐ray Spectroscopy analyses, which improved the interfacial bonding and increased fiber roughness. Biosilica particles (80–90 nm) reinforced the composite, leading to improved mechanical properties. The 3% biosilica composite (ERB3) achieved the highest tensile strength (103.25 MPa), flexural strength (193.3 MPa), and a balanced combination of fiber reinforcement and biosilica content. The 5% biosilica composite (ERB5) showed higher impact strength and ductility but had slightly lower tensile and flexural strength due to particle agglomeration. Dynamic Mechanical Analysis indicated that ERB3 had the best storage modulus (E′), indicating increased stiffness and rigidity, with less energy dissipation and better load‐bearing capacity. Hydrophobicity decreased as biosilica content increased, with ERB5 displaying the lowest contact angle (65°), though all composites maintained water resistance suitable for moisture‐resistant applications. Thermal degradation tests revealed that ERB5 had the highest thermal stability, with a peak degradation temperature of 480°C and the highest char residue (8.2%). Wear tests demonstrated that biosilica‐reinforced composites significantly outperformed pure epoxy (EP) in wear resistance, with ERB1 showing the best results. In summary, ERB3 provides the best overall performance with superior mechanical and tribological properties, while ERB5 excels in impact strength and thermal stability.