Snail mucus-inspired soybean meal adhesive with excellent mechanical strength and prepressing performance

Abstract

Plant-derived soybean protein adhesives have potential to replace petroleum-based resins. However, soybean protein adhesives generally face a compromise between bonding strength and toughness, and these adhesives display insufficient prepressing strength, hindering their further industrial application. Herein, inspired by the interface drainage snail mucus, we integrated electrostatic interaction and hydrogen bonding into adhesive network to achieve excellent mechanical strength and prepressing performance. Specifically, oppositely charged phytic acid functionalized boron nitride nanosheets (PA@BNNSs) and quaternized chitosan (QCS) formulated with soybean meal (SM) to produce the biomimetic adhesive. The electrostatic interaction formed between PA@BNNSs and QCS serves to enhance the cohesive strength of the adhesive in the wet state, while also improving its wettability. Benefiting from multiple interactions and nanomaterial reinforcement, the biomimetic adhesive achieved a prepressing strength of 0.65 MPa and wet shear strength of 2.53/1.50 MPa, which were 124 % and 80.7/117 % higher than the pure SM adhesive. In addition, the biomimetic adhesive exhibited good flame-retardant and mildew resistance properties. Therefore, this work offers a route to prepare advanced multifunctional bio-based adhesives.