木质素改性及其在胶粘剂领域应用

Modification of lignin and its application in the field of adhesive

木质素是植物体内的一种天然高聚物,其刚性结构为植物纤维提供了一定的支撑强度。由于木质素具有含量丰富、无毒无害和生物可降解的优良特性,近年来正逐渐取代不可再生石油基原料制造胶粘剂。木质素在胶粘剂中可以作为填料,也可以作为反应性组分;酚类结构使其具有取代传统酚醛树脂中苯酚组分的潜力;酚羟基可以方便地接枝环氧化合物,可以替代多元醇与异氰酸酯发生反应。木质素或改性木质素基酚醛、环氧和聚氨酯胶粘剂已经被用于木构件如纤维板、刨花板、胶合板的粘接。本文旨在从木质素和改性木质素出发,介绍不同类型木质素基胶粘剂的结构特征、固化性能、粘接强度以及潜在应用价值,并对其未来发展进行了展望。

Lignin serves as a natural polymer in plants,and its rigid structure provides a certain degree of support strength for plant fibers.In recent years,lignin is gradually replacing non-renewable petroleum-based raw materials in the manufacturing of adhesive due to its abundance content,non-toxic nature,harmless and biodegradable properties.Lignin can serve either as filler or as reactive component in the adhesive.With phenolic structure,it shows promising potential to replace phenol component in conventional phenolic resin.Meanwhile phenolic hydroxyl group can be grafted with epoxy group conveniently,replacing polyols to react with isocyanates.Lignin or modified lignin based phenolic,epoxy,and polyurethane adhesives have been used for the bonding of wood components such as fiberboard,particleboard,and plywood.In this article,the structural characteristics,curing performance,bonding strength,and potential application value of different types of lignin based adhesives were introduced from the perspectives of lignin and modified lignin,and their future development was prospected.