硫酸盐蒸煮过程中溶出木质素特性的变化

The Changes of Characteristics of Dissolved Lignin from Kraft Cooking

用化学和波谱分析研究了常规硫酸盐制浆过程中溶出木质素化学结构特性的变化。结果表明 ,溶出木质素的缩聚程度较高 ,其共轭双键的增加主要发生在蒸煮前期。蒸煮过程中木质素的降解溶出伴随着甲氧基的脱除反应 ,木质素溶出之后基本不存在脱甲氧基反应。随着蒸煮反应的进行 ,溶出木质素的醇羟基不断减少 。

Structure changes of dissolved lignin during kraft cooking were characterized by chemical and spectral analysis.The results show that the condensation degree of dissolved lignin is relative higher and the increase of conjugated double bond is mainly proceeded at the early stage of cooking.Lignin was dissolved with demethylation reaction in cooking process.There is almost no demethylation after lignin is dissolved.With the proceeding of cooking reaction, the alcoholic hydroxyl of dissolved lignin reduces,but phenolic hydroxyl content increases gradually.