Sucrose transformation: synthesis and characterization of innovative water-resistant wood adhesives driven by the Maillard reaction

The wood adhesive industry’s reliance on traditional petroleum-based adhesives poses environmental and health risks, necessitating the development of sustainable, bio-based alternatives. To develop a modified sucrose-based adhesive with good water resistance, the hydrolysis products of sucrose were crosslinked with polyethyleneimine (PEI) through the Maillard reaction to form a dense crosslinked network. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the interaction between the sucrose derivatives and PEI. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) revealed the thermal curing behavior and thermal stability of the modified sucrose-based adhesive. Additionally, the optimal preparation conditions for the modified sucrose-based adhesive were investigated. Compared to unmodified natural sucrose-based adhesives, the wet shear strength and dry shear strength of the modified sucrose-based adhesive were increased by 212% and 279%, both exceeding the Chinese national standard GB/T 9846-2015 (0.7 MPa). This process is simple and cost-effective, producing a formaldehyde-free, water-resistant sucrose-based adhesive that offers a sustainable solution for wood adhesives with significant application potential.