Natural organic-inorganic hybrid structure enabled green biomass adhesive with desirable strength, toughness and mildew resistance

Plant based proteins are green, sustainable, and renewable materials that show the potential to replace tradi-tional formaldehyde resin. High performance plywood adhesives exhibit high water resistance, strength, toughness, and desirable mildew resistance. Adding petrochemical-based crosslinkers is not economically viable or environmentally benign; this chemical crosslinking strategy makes the imparted high strength and toughness less attractive. Herein, a green approach based on natural organic-inorganic hybrid structure enhancement is proposed. The design of soybean meal-dialdehyde chitosan-amine modified halloysite nanotubes (SM-DACS-HNTs@N) adhesive with desirable strength and toughness enhanced by covalent bonding (Schiff base) cross -linking and toughened by surface-modified nanofillers is demonstrated. Consequently, the prepared adhesive showed a wet shear strength of 1.53 MPa and work of debonding of 389.7 mJ, which increased by 146.8 % and 276.5 %, respectively, due to the cross-linking effect of organic DACS and toughening effect of inorganic HNTs@N. The introduction of DACS and Schiff base generation enhanced the antimicrobial property of the adhesive and increased the mold resistance of the adhesive and plywood. In addition, the adhesive has good economic benefits. This research creates new opportunities for developing biomass composites with desirable performance.

Automated summary

Plant based proteins have the potential to replace formaldehyde resin as green and sustainable materials. A new adhesive based on soybean meal-dialdehyde chitosan-amine modified halloysite nanotubes was developed, enhancing strength and toughness through covalent bonding cross-linking and nanofiller toughening. This research opens up opportunities for developing biomass composites with desirable performance.