Achieving sustainable and highly efficient wood bonding through synergistic plant root-driven penetration mode with a hyperactive interface

Abstract

Wood adhesives are widely used in furniture manufacturing, the construction industry, and the fabrication of the internal components of aircraft, cars, and sports equipment. Therefore, the development of wooden adhesives with high stability, strength, and efficiency is a vital research area. Although most studies have focused on improving the bonding properties of adhesives, achieving direct interface control from wood remains a challenge. This study was designed based on the plant root-driven adhesion method to create a hyperactive-interface self-driven regulated wood capable of spreading adhesive into the wood and inducing crosslinking to improve adhesive strength. A multi-poly silicate network structure with multiple reactive sites was formed through the self-polymerization of sodium silicate and crosslinking with dimethylol dihydroxy ethylene urea (DMDHEU) to achieve densified wood and improve the reactivity of the wood surface and interior. Consequently, the environmentally friendly polyvinyl acetate (PVAc) underwent a self-driven bonding process with the wood. These findings indicate that PVAc penetrated the interior of the wood, disrupting the combination of sodium silicate and DMDHEU and grafting onto the reactive sites. This process resulted in a tightly bonded interface connection. Consequently, the shear strength increased from 4.4 to 5.5 MPa, and the wood breaking rate increased from 21.00 % to 45.80 %, representing a 25 % and 118.10 % increase, respectively. Moreover, the tensile strength of the wood in longitudinal joints, transverse joints, miter joints, and mortise–tenon joints was assessed. The results revealed that the sodium silicate/DMDHEU-regulated wood (SS/DDRW) exhibited significantly higher adhesive strength than the original wood (OW). Hence, this bionic design represents a simple and efficient strategy for developing wood adhesives.