A High‐Performance Bio‐Adhesive Using Hyperbranched Aminated Soybean Polysaccharide and Bio‐Based Epoxide

Abstract Wood adhesives fabricated from biomass can substitute formaldehyde‐based ones, reducing the consumption of fossil resources and eliminating formaldehyde pollution. In this study, a novel and sustainable water‐soluble soybean polysaccharide (WSSPS)‐based adhesive is designed. Specifically, a hyperbranched aminated polysaccharide (HBPA–g–WSSPS), as an adhesive matrix, is synthesized via grafting reaction between oxidized WSSPS and hyperbranched polyamide (HBPA). Triglycidylamine, a bio‐based epoxide cross‐linker, reacted with the HBPA–g–WSSPS to afford a cross‐linked hyperbranched network, providing strong cohesion for the adhesive. Additionally, polyacrylamide imparted an adjustable viscosity to the adhesive. The resultant WSSPS‐based adhesive enhanced the wet shear strength of plywood (1.24 MPa) by 49% compared to the E 0 ‐level industrial‐use melamine‐urea‐formaldehyde (MUF) resin and by 26% compared to the industrial‐use soybean meal/polyamidoamine‐epichlorohydrin (PAE) adhesive. In addition, the adhesive has characteristics similar to those of the MUF resin, including viscosity, coating performance, hot‐pressing conditions, and dry bond strength, which are superior to those of the soybean meal/PAE adhesive. This developed polysaccharide‐based adhesive can potentially enhance various composites and can be used in industrial sectors.