漆酶作用下5-5′结构木素模型化合物与对-羟基肉桂酸的脱氢聚合反应

具有5-5′结构的木素结构非常稳定,难以在制浆过程和废水处理中降解,但酚型5-5’结构能在漆酶的作用下发生聚合。为了了解在漆酶的催化作用下5-5’结构型木素结构与对-羟基肉桂酸之间的共聚性能,进而为制浆废水中木素的酶催化絮凝技术的开发提供理论基础,本文研究了在漆酶催化作用下,对-羟基肉桂酸与5-5’结构木素模型物（脱氢二香草醇）的聚合反应。应用凝胶渗透色谱（GPC）测定了聚合产物的相对分子量,采用红外光谱、核磁共振技术探讨了对-羟基肉桂酸与5-5′结构木素模型物的脱氢聚合产物的化学结构。研究结果表明：在漆酶催化作用下,对-羟基肉桂酸与5-5′结构木素模型物发生脱氢聚合反应,形成典型的DHP。聚合后相对分子质量明显增大,相对分子量Mn由306提高到2106。结构单元之间的连接方式主要是通过β-O-4、α-O-4、β-β等。

Dehydrogenation polymerization of p-hydroxycinnamic acid and 5-5' type lignin model compound catalyzed by laccase

The 5-5′ type lignin substructure is very stable during kraft pulping and it is difficult to degrade in the treatment of wastewater from pulping. However, phenolic 5-5′ can polymerize by laccase. In order to understand the co-polymerization between 5-5′ type lignin model and p-hydroxycinnamic acid in existence of laccase to provide the theoretic basis for the development of precipitation and flocculation of the lignin in effluent from pulping process, the polymerization reaction between p-hydroxycinnamic acid and a lignin model compound of phenolic 5-5′ type lignin model compound, i.e. dehydrodiacetovanillione, catalyzed by laccase was studied .Gel permeation chromatography （GPC） was used to analyze the molecular weights of the polymerization products. FT-IR and NMR spec-troscopy were employed to determine the chemical structure of the polymer obtained. The result indicates that dehydrodivanillyl alcohol can polymerize with p-hydroxycinnamic acid catalyzed through dehydrogenation. While GPC determination indicated the molecular weight Mn increased from 306 to 2106. The linking ways of structure units were mainly though β-O-4、α-O-4、β-β structures.