Functionalization of cellulose with amine group and cross-linked with branched epoxy to construct high-performance wood adhesive.

Sustainable biomass resources are favored by researchers on account of their biodegradability and biocompatibility, which is a replacement for non-renewable fossil fuels. The development of low-carbon, green, and high-value bio-based adhesives are the inevitable trend of the industry development. However, the main factors limiting their application are poor water resistance and low bonding performance. Herein, the crosslinking network was constructed based on the reaction between the epoxy groups of trimethylolpropane glycidyl ether (TMPEG) and the amino groups of the synthesized aminated cellulose (AC) to form an interlocking bond. Through the synergy of covalent bond, electrostatic interaction, and hydrogen bond, the bonding strength and water resistance of the proposed adhesive can be effectively improved. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and solid-state nuclear magnetic resonance spectroscopy (13C NMR) demonstrated the formation of epoxy-amine network. The excellent bonding strength and water resistance of the adhesive made with AC and TMPEG (AC-TMPEG) are mainly reflected by the dry lap shear strength of 2.56 MPa and the wet lap shear strength of 1.94/2.09 MPa after soaking in 63 °C/boiling water for 3.0 h. This study reveals an approach for manufacturing wood adhesive with superior bonding performance and exceptional water resistance.