Brown algae-inspired, multifunctional and bionic soy protein-based wood composite adhesive
Raw materials based on renewable sources often lack some performance in the final product e.g. adhesives. This work overcomes this flux by special combination of the soy protein with bamboo cellulose nanofiber and montmorillonite – leading to alternative, low formaldehyde wood composite adhesives.
Promising application prospects of soy protein adhesives (SPI) as green alternatives to formaldehyde-based resins, often show poor bonding strength and unsatisfactory water resistance, restricting the practical application. Inspired by brown alga bionics and organic–inorganic hybridization system, a bionic and multifunctional soy protein adhesive was prepared utilizing rosin acid derivative, bamboo cellulose nanofiber, and montmorillonite.
Optimal formulation created a modified SPI which was optimized by response surface methodology. The mod. SPI presented excellent dry and wet shear strengths (2.41 and 1.41 MPa), which were increased by 270% and 231% compared to pure SPI. Moreover, the strength of the modified adhesive far exceeded the China National Standard (0.70 MPa). Molecular docking strategy and finite element analysis also confirmed strong interactions within mod. SPI. In addition, mod. SPI exhibited exceptional water and organic solvent resistance, owing to the dense cross-linking structure.
Remarkable coating properties enabled mod. SPI to be coated evenly in dry and wet environments. Furthermore, mod. SPI showed outstanding flame-retardant properties, improving safety in practical use. Meanwhile, life cycle assessment of mod. SPI revealed environmentally friendly features, such as low formaldehyde pollution and greenhouse gas emission. Therefore, this proposed green, multifunctional, and bionic adhesive demonstrated an eco-conscious alternative to traditional formaldehyde-based resins for the large-scale fabrication of wood composite materials
Source: ACS Sustainable Chem. Eng. 2025
