脱甲基硫酸盐木质素代替酚在木材粘合剂中的应用

DEMETHYLATED KRAFT LIGNIN AS A SUBSTITUTE FOR PHENOL IN WOOD ADHESIVE

硫酸盐木质素经脱甲基增加了与甲醛反应的活性，且因在木质素结构中形成了邻苯二酚结构，其反应性能较苯酚更活泼。溶于碱溶液的脱甲基木质素与甲醛一起直接加入粘合剂中，热压时，不增加热压时间。有可能以脱甲基木质素完全取代酚并得到满意的胶合板粘合剂，脱甲基木质素的生产成本约为苯酚的一半。

By demethylating kraft lignin the number of reactive sites with formaldehyde is increased and its reactivity towards formaldehyde is also increased because of catechol formation in the lignin structure. Through demethylation the lignin can be made more reactive than phenol itself. When add the demethylated lignin dissolved in an alkaline so-lution,together with the required formaldehyde ,directly to the adhesive formulation,the resol intermediate is formed during hot pressing and the press time is not increased.It is possible to substitute phenol completely with demethylated lignin and obtain an accept-able plywood adhesive. The cost of producing demethylated lignin would be about half the cost of phenol.