Locking Water, Unlocking Performance: Lignosulfonate‐Driven Topology‐Engineered Hydration for High‐Performance Bio‐Based Adhesives

Developing robust, durable, bio‐based adhesives for high‐performance engineered wood is critical for sustainability but remains a formidable challenge. Rapid moisture loss is an intrinsic drawback of bio‐based adhesives, which causes insufficient interfacial contact and weakened cohesion, compromising mechanical integrity. Here, a topology‐engineered hydration strategy is proposed to develop a soybean protein/lignosulfonate‐polyacrylamide (SP/LS‐PAM) adhesive with robust adhesion and efficient water retention. Unlike conventional water retention strategies, LS‐PAM acts as a structural hydration regulator, where its flexible PAM side chains behave as “molecular sponges”, achieving kinetic confinement of water molecules through intensive water‐polymer complexation. As a result, the adhesive exhibits an impressive dry shear strength of 3.22 MPa, surpassing that of reported protein‐based adhesives. After 30 min of water evaporation, the SP/LS‐PAM adhesive retains 87.1% of its bonding strength (1.08 MPa), representing a 1440% improvement over the SM adhesive. Life cycle assessment (LCA) confirms that this adhesive avoids the carcinogenic hazards and resource burdens associated with urea‐formaldehyde (UF) resins. Coupled with excellent biodegradability and a competitive cost (272–312 USD ton −1 ), this work presents a viable, sustainable alternative to traditional synthetic resins.