Latest Advancements in the Development of High-Performance Lignin- and Tannin-Based Non-Isocyanate Polyurethane Adhesive for Wood Composites

The depletion of natural resources and increasing environmental apprehension regarding the reduction harmful isocyanates employed in manufacturing polyurethanes (PUs) have generated significant attention from both industrial academic sectors. This is focused on advancing bio-based non-isocyanate polyurethane (NIPU) resins as viable sustainable substitutes, possessing satisfactory properties. review presents a comprehensive analysis progress made developing NIPU polymers for wood adhesive applications. main aim this paper to conduct latest advancements production high-performance derived lignin tannin composites. A evaluation was conducted scholarly publications retrieved Scopus database, encompassing period January 2010 April 2023. In manufacturing, exploration substitute materials imperative, due their inherent toxicity, high cost, limited availability. process demethylation carbonation has potential produce polyphenolic compounds that possess hydroxyl carbonyl functional groups. Bio-based NIPUs can be synthesized through reaction involving diamine molecules. Previous studies provided evidence indicating exhibit enhanced mechanical properties, decreased curing temperatures shortened pressing durations, are devoid isocyanates. characterization adhesives based using various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TGA), matrix-assisted laser desorption/ionization with time-of-flight (MALDI-TOF) mass spectrometry, gel permeation chromatography (GPC). performance tannin-based shown superior lignin-based NIPUs. elucidates alternate sources polyols NIPUs, specifically application adhesives.