木质素光降解机理研究进展

Research Progress on Lignin Photo Degradation Mechanism

从木质素模型及原本木质素2个方面综述木质素光降解的研究现状。木质素模型研究表明,光降解是典型的自由基反应,主要通过游离酚途径、羰游基途径和苯甲酰甲基芳醚途径反应,苯氧自由基是光化学反应的重要中间产物。木质素光降解是个氧化过程,伴随着碳的氧化态升高、非共轭羰基减少、共轭羰基增加,大分子木质素发生解聚,最终形成对醌、邻醌等发色基团及苯甲酸、苯甲醛等可溶性小分子酚类化合物,木质素含量明显降低。木质素光化学反应的机理研究中,木质素模型和原本木质素存在一定差距,分子和细胞水平上的深入研究将是未来的发展方向。

The paper summarized current studies concerning phododegradation of lignin model and natural lig- nin. The results of lignin model studies showed that lignin photodegradation was a typical free radical reaction, and hydroxyl radical, carbonyl groups and phenacyl aryl ether cleavage were the main type of reaction. Moreover, phe- noxy radical was very important intermediate product. Lignin photodegradation is an oxidation and degradation process, during which carbon＇s oxidation state raised, conjugated carbonyl increased and non-conjugated carbonyl decreased, followed by high molecular lignin depolomerizing to some extent, α - quinone and β - quinone were main reason contribute to the discolor, there were soluble small molecular product such as benzoic acid and benzal- dehyde. In the end, the paper pointed out the key problem of the current study and the development direction.