Effect of sodium lignosulfonate on bonding strength and chemical structure of a lignosulfonate/chitosan-glutaraldehyde medium-density fiberboard adhesive

Abstract

Sodium lignosulfonate/chitosan-glutaraldehyde adhesive (L/C-G) has potential in environment-friendly wood-based panel adhesive applications. However, the effect of sodium lignosulfonate on the bonding strength and chemical structure of L/C-G was not elucidated. Herein, the role of sodium lignosulfonate in L/C-G was studied in detail by characterizing the mechanical properties and water resistance of medium-density fiberboards (MDFs) prepared using L/C-G as adhesives. The functional groups, thermal stability, and crystalline structure of L/C-G with various mass ratios of sodium lignosulfonate to chitosan were also characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction, respectively. The results show that an appropriate amount of sodium lignosulfonate in L/C-G was beneficial for its bonding strength, and the MDFs with 1:2 mass ratio of sodium lignosulfonate to chitosan showed superior mechanical properties and comparable water resistance with a commercial panel. Besides the reaction between sodium lignosulfonate and chitosan, guaiacyl units, or lateral chain of sodium lignosulfonate might also react with glutaraldehyde and result in C-O-C groups, helpful for the bonding strength of L/C-G.

A facile strategy to fabricate a lignin-based thermoset alternative to formaldehyde-based wood adhesives

“…3(a and b)) clearly showed that the peaks at 3200–3450 cm −1 (hydroxyl and amino) and 1590 cm −1 (–NH bending vibration) significantly decreased, suggesting that reactions between the amino groups of the crosslinker and the hydroxyl groups of the lignin occurred. Meanwhile, the peaks at 1089 cm −1 were attributed to the increase in the ether bonds, 50 due to condensation reactions between lignin molecules. 51 In the XPS analysis (Fig.…”

Comparative Study of the Extraction of Cu(II) and Fe(II) Ions Using Chitosan and Modified Chitosan/Polyvinylpyrrolidone Adsorptive Membranes: Adsorption, Kinetic, and Thermodynamic Study

“…For the detection of Fe 3+ ions in acidic environments, C-SS-CDs have a 40% photoluminescence quantum yield in diluted acid solution. 58 3.14.5. Chitosan as a Supercapacitor.…”

pH-Responsive Intelligent Antibacterial Coatings Based on 2D-COF for Controlled Release of Capsaicin

“…At present, the main methods of intelligently controlling the release of antifouling agents are pH response, enzyme response, and temperature response . Up to now, a variety of nanomaterials with good controlled-release properties have been reported, including poly­(vinyl alcohol) microspheres in a silk sericin-based hydrogel, composite films with an adjustable number of layers using sodium alginate (SA), chitosan (CS), and activated charcoal (AC), microcrystals, polyvinyl alcohol/chitosan microspheres, and a selenium-rich tea set. , Chitosan (CS) has antibacterial properties due to the interaction between its positively charged amino group and the negatively charged cell membrane of bacteria. , The nanocapsules made from CS exhibit typical pH response characteristics due to the large number of amino groups contained in the side chain. , In addition, the intelligent delivery of fungicides can be realized by the modification of chitosan. , Our research group has developed a capsaicin@chitosan (CAP@CS) microcapsule with pH response performance, which can realize the intelligent controlled release of the natural bactericide CAP, which plays an effective sterilization and antifouling role. , However, its dispersion is limited. In order to improve the dispersion on the basis of pH response sterilization, we hope to introduce other materials to further improve the performance of intelligent response controlled release sterilization. , Two-dimensional materials (graphene, covalent organic frameworks) have great potential for marine protective materials, such as corrosion protection and fouling protection, due to their excellent adsorption characteristics, mechanical strength, thermal stability, and other characteristics. , In recent years, 2D covalent organic frameworks (COFs), which are typical representatives of 2D nanomaterials, have the characteristics of diverse synthesis methods, large specific surface area, stable physical and chemical properties, and broad application prospects in different fields. , COF-MOF hybrid materials have ingenious and obvious structural characteristics and excellent performance .…”

“…37,38 In addition, the intelligent delivery of fungicides can be realized by the modification of chitosan. 39,40 Our research group has developed a capsaicin@ chitosan (CAP@CS) microcapsule with pH response performance, which can realize the intelligent controlled release of the natural bactericide CAP, which plays an effective sterilization and antifouling role. 41,42 However, its dispersion is limited.…”