Soybean protein "mechanically interlocked" bonding of polysaccharide and MXene to improve the strength and toughness of biomass adhesive.

Simultaneously improving the strength and toughness of soybean protein adhesives is a huge challenge. The multi-scale enhancement strategy proposed in this study introduced MXene nanosheets and oxidized sodium alginate (OSA) to improve mechanical properties. The polymer network framework with high crosslink density dissipates energy by restricting the slip of the SPI molecular chains, and MXene act as stress dispersers in the polymer network in order to solve the challenge of the strength-toughness balance. The prepared biomass-based adhesives with high adhesion (dry/wet shear strength 1.93 MPa/1.33 MPa), high toughness (adhesion work 810.9 mJ), high thermal stability, high residual rate (92.53 %), low moisture absorption rate (11.18 %), and long storage time (12 d). Additionally, the application of SOM-5 adhesive reduces the burden of petrochemical resource extraction for adhesive production and contributes to the sustainable development of the wood industry. Most importantly, it presents an adoptable strategy for resolving the tension between strength and toughness of composite materials. [Display omitted] • The adhesive shows excellent wet bond performance for wood, 1.33 MPa. • The toughness of prepared adhesive increased by 377 % compared to unmodified one. • Multiple interactions greatly improve the properties of the adhesive. • Liquid adhesive storage time is effectively extended. [ABSTRACT FROM AUTHOR]