Preparation a novel high performance glucose-based wood adhesive with hyperbranched cross-linked network by air oxidation

Utilizing biomass resources to develop environmentally friendly and sustainable adhesives, replacing traditional petroleum-based adhesives, has become an effective way to solve resource shortages and environmental pollution. Glucose, as the most widely distributed reducing monosaccharide in nature, has great potential to replace aldehyde-based adhesives in the production of artificial boards. In this study, G-PEI adhesive was prepared from glucose and PEI by one pot one-step method on the basis of air oxidation and Maillard reaction. The crosslinking mechanism between glucose and PEI was confirmed through detailed Fourier transform-infrared (FT-IR), 13C nuclear magnetic resonance (13C NMR), X-ray photoelectron spectroscopy (XPS), and liquid chromatography-mass spectrometry (LC-MS) analysis. The results showed that the improvement of G-PEI adhesive bonding properties was attributed to the formation of cross-linking network and the synergistic effect of covalent bond and hydrogen bond. As a biomass adhesive prepared without additional oxidant, the maximum wet strength in boiling water of wood-based panels prepared with G-PEI adhesive reaches 1.55 Mpa under the hot pressure condition of 200 °C. Even if the hot-pressing temperature drops to 160 °C, the wet shear strength in boiling water can still reach 0.67 MPa, which is better than relevant reports. This study revealed a method for the simple preparation of high performance wood adhesives by oxidizing glucose through air.