Phenol formaldehyde‐flax fabric (<scp>PF</scp>‐F) hybrid composites reinforced with cellulose nanofiber (<scp>CNF</scp>)—mechanical, morphology, electrical conductivity, electronic structure, optoelectronic, and charge transfer properties

Abstract For developing an eco‐friendly world, a sustainable solution has encouraged to use natural fibers. Among the various options, lignocellulose fiber‐reinforced composites have captured the interest of material experts and engineers. These remarkable materials offer plentiful supply, inherent sustainability, easily degradability, and affordability, making them an attractive choice for a multitude of uses. Herein, we prepared a series of hybrid cellulose nanofiber (CNF)‐reinforced phenolic composites. Flax fabric was coated with CNF followed by phenolic resin coating was made in this work to check the mechanical, morphological behavior, electrical conductivity, electronic structure, opto‐electronic, and charge transfer properties. We found that 0.5 CNF showed better tensile properties, greater AC conductivity, dielectric constant, and dielectric loss compared with other composites. The electronic structure, opto‐electronic, and charge transfer properties of the PF‐resin/nanocellulose polymer nanocomposite have been systematically examined using density functional theory (DFT). The findings indicate that the PF‐resin/cellulose nanocomposite undergoes intramolecular charge transfer (CT) in response to an external electric field. The negative binding energy exhibited between the DFT optimized PF‐resin/cellulose nanocomposite shows the complex is stable and energy‐favorable. Highlights The impact of CNF on the properties PF‐F hybrid composites was investigated. The mechanical performance has been improved by the addition of CNF. The incorporation of CNF improved the fracture toughness of the composites. The fabricated composite has negative binding energy from DFT studies. A promising high‐performance electroactive polymer and structural material.