Preparation of a boiling water resistant and flame retardant wood adhesive using novel hyperbranched phosphorus containing polyamine and silicon containing tannin core-shell structure.

The use of aldehyde starch and amine compounds for the preparation of wood adhesives has improved their properties, but the use of expensive oxidizing agents have inevitably limited the development of starch adhesives. As we all know, air is one of the greenest and most environmentally friendly oxidizers. In this study, a novel hyperbranched polyamine (DIHP) containing phosphorus element was synthesized. Then, α-amylase was used to hydrolyze starch partially into glucose and maltose, and S-DIHP adhesive was prepared with DIHP and starch hydrolysis products based on enzyme catalyzed hydrolysis strategy, air oxidation strategy, and hyperbranching cross-linking network strategy. Because of the synergistic effect of imine bonding, amide bonding and hydrogen bonding within the adhesive, the S-DIHP adhesive was endowed with good boiling water resistance. Finally, the nano hybrid DE @ TA with polysiloxane (DE) as the core and tannic acid (TA) as the shell was prepared. The incorporation of DE @ TA not only improved the bonding performance of the adhesive, but also enhanced the flame retardancy, and the ultimate oxygen index of the adhesive was up to 32.1 %, reaching the standard for flame retardant materials: B2 class (GB8624-2012). This study provides a new idea for developing multifunctional starch adhesive.