Effective electromagnetic interference (EMI) shielding is essential for safeguarding modern electronic systems, driving the need for lightweight and multifunctional composites. This study reports a novel vinyl ester composite reinforced with 40 vol.% silane-treated Odorata cellulose microfiber and varying silane-treated biocarbon contents, designed to achieve combined structural, EMI shielding, flammability, and dielectric performance. The VMB2 composite (40 vol.% fiber and 3 vol.% biocarbon) exhibited optimal mechanical properties, with tensile strength of 121 MPa, flexural strength of 134 MPa, impact energy of 3.19 J, and hardness of 82 Shore D, attributed to improved interfacial bonding and efficient stress transfer. EMI shielding effectiveness increased with biocarbon loading, reaching 29.7 dB, governed primarily by absorption-dominated attenuation. Flammability tests showed a reduced flame propagation rate from 11.4 to 5.8 mm/min while maintaining UL-94 HB and V-0 ratings. Dielectric permittivity and loss increased with biocarbon addition due to enhanced interfacial polarization. Scanning Electron Microscopic (SEM) analysis revealed a transition from brittle to reinforcement-dominated fracture. These results demonstrate that controlled biocarbon incorporation enables tunable, multifunctional vinyl ester composites suitable for electronic device enclosures, automotive electronic housings, communication equipment casings, and lightweight EMI shielding panels in aerospace structures.
Pattar et al. (2026) studied this question.