Sugar-based wood adhesives: a review

Growing environmental concerns and strict formaldehyde emission regulations have accelerated the transition toward sustainable and bio-based adhesives for wood-based composites. Among bio-derived precursors, sugars and their derivatives have attracted considerable attention due to their renewability, high functionality, and abundance. This review summarizes the current advances in formulation, chemistry, and performance of sugar-based adhesives used in wood bonding applications. Various monosaccharides, disaccharides, and polysaccharides—such as glucose, sucrose, starch, and cellulose—have been explored as key reactants or co-monomers in thermosetting adhesive systems. Their reactivity is primarily governed by hydroxyl and carbonyl functional groups, which enable esterification, etherification, or dehydration crosslinking reactions under acidic or catalytic conditions. Studies have shown that sugar-based resin formulations have demonstrated promising adhesion strength and low emissions, providing viable alternatives to traditional formaldehyde-based wood adhesives. However, challenges remain in improving water resistance, curing efficiency, and long-term durability. The review also highlights emerging modification strategies, including esterification and polycondensation, acid-catalyzed sugar dehydration and furan-based adhesive systems, Maillard-Type reactions, oxidized sugars and Schiff-base adhesives, crosslinking with tannins, and sugar-based non-isocyanate polyurethane-based wood adhesives. Finally, perspectives on industrial scalability, processing optimization, and integration into circular bioeconomy frameworks are discussed.