Air oxidation and hyperbranched crosslinking approach for a boiling water-resistant sucrose-derived wood adhesive

At present, petroleum-based adhesives, which are widely used in the wood adhesive sector, are facing problems such as environmental pollution and harm to humans. It has therefore become crucial to replace traditional petroleum-based adhesives with new biomass-based adhesives. Sucrose, which is widely available in plants and has the advantages of being sustainable and inexpensive, provides the basis for the preparation of biomass adhesives. In this experiment, the preparation of sucrose based hyperbranched polyamine adhesive was achieved by air oxidation and hyperbranched cross-linking strategies. The structure of the sucrose based hyperbranched polyamine adhesive was investigated by FTIR, 13C NMR, XPS, LC-MS, DSC and GPC, and a tightly cross-linked network structure was formed by sucrose oxidation and internal graft copolymerisation of polyamino compounds. The best performing sucrose-based biomass binder was screened by the controlled variable method by varying the sucrose/hyperbranched polyamine molar ratio, reaction time, hydrolysis time and reaction temperature respectively. While the dry shear strength of the plywood reached 2.40 MPa, the wet shear strength in hot water and boiling water at 63 °C reached 1.16 MPa and 1.10 MPa respectively. The experimental procedure is simple, the material is inexpensive and the sucrose based hyperbranched polyamine adhesive produced has excellent properties. This hyperbranched crosslinking strategy provides a potential synthetic approach for the development of biomass-based wood adhesives.