Boiling Water Resistant Fully Bio-Based Adhesive Made from Maleated Chitosan and Glucose with Excellent Performance

Abstract Preparing green wood adhesives using renewable biomass resources is significant. A three-component biomass adhesive CSC-G was prepared by combining chitosan, maleic anhydride, and glucose. Characterization using Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) demonstrated that dehydrated malic acid serves as a bridge for connecting chitosan and glucose. The introduction of glucose enriches the crosslinking density, thereby improving the bonding strength. In addition, the effects of the mass ratio of CSC to glucose, hot pressing temperature, and hot-pressing time on CSC-G adhesive were also investigated. The excellent performance of CSC-G is mainly shown in that when pressed at 160 ℃, the shear strength of three-layer plywood remains at 0.88 MPa after soaking in boiling water for 3 hours, and the curing temperature is better than the previously reported polyester adhesive. As an all-biomass polyester adhesive, CSC-G adhesive has a lower curing temperature and excellent performance and provides a new approach to developing high-performance chitosan-based wood adhesives.