Bone Tissue-Inspired Organic–Inorganic Hybrid Network for Hot-Pressed Peanut Meal Protein-Based Adhesives with High Water Resistance

Abstract A bone-inspired organic–inorganic hybrid adhesive was constructed using hot-pressed peanut meal (HPM), an agricultural byproduct-derived protein resource, through sequential integration of urea–formaldehyde resin, polyamide amine–epichlorohydrin (PAE), and nFe3O4 nanoparticles. The effects of nFe3O4 incorporation on the bonding performance and structural characteristics of the adhesive were investigated. The optimized PAE/HUF/nFe3O4 adhesive exhibited dry, wet, and boiling water bonding strengths of 2.40, 1.63, and 1.20 MPa, respectively, accompanied by a 79% increase in debonding work. Structural analyses demonstrated that covalent cross-linking and organic–inorganic interfacial interactions contributed to the enhanced mechanical performance and durability. The results indicate that nFe3O4 reinforcement effectively improves the strength and toughness of HPMP-based adhesives through the construction of a hierarchical hybrid network.