一种羟基富集的乙酸木质素聚氨酯胶黏剂及其制备方法

本发明公开了一种羟基富集的乙酸木质素聚氨酯胶黏剂及其制备方法，属于聚氨酯胶黏剂制备领域。该方法包括以下步骤：(1)有机溶剂抽提生物质原料，除去其中多糖、树脂、可溶性单宁和颜料等不期望的物质，得到精制乙酸木质素；(2)将乙酸木质素进行去甲基化改性，得到富含羟基的去甲基化乙酸木质素；(3)将去甲基化改性后的木质素与计量好的多元醇类、异氰酸酯及催化剂共聚，得到高强度聚氨酯胶黏剂材料。本发明解决了木质素反应活性不高、反应位点不多、聚氨酯胶黏剂成本较高、降解困难等问题。该聚氨酯胶黏剂具有良好的力学性能和粘附性，所需的生物质原料来源广泛，对环境友好可降解，实现了木质素的高值化利用。

This invention discloses a hydroxyl-enriched acetic acid lignin-based polyurethane adhesive and its preparation method, which belongs to the field of polyurethane adhesive preparation. The preparation method includes the following steps: (1) Extract biomass raw materials with organic solvents to remove undesired substances such as polysaccharides, resins, soluble tannins and pigments, so as to obtain refined acetic acid lignin; (2) Perform demethylation modification on the acetic acid lignin to obtain demethylated acetic acid lignin rich in hydroxyl groups; (3) Copolymerize the demethylated modified lignin with metered polyols, isocyanates and catalysts to obtain high-strength polyurethane adhesive materials. This invention solves the problems of low reactivity of lignin, insufficient reaction sites, high cost of polyurethane adhesives and difficult degradation. The prepared polyurethane adhesive has good mechanical properties and adhesion, the required biomass raw materials are widely sourced, environmentally friendly and degradable, and realizes the high-value utilization of lignin.