酸水解木质素的结构及热解产物分析

STRUCTURE AND PYROLYSIS PRODUCTS ANALYSIS OF ACID HYDROLYSIS LIGNIN

采用木质纤维典型稀酸水解残渣为实验原料,对其理化特性进行分析。对酸水解木质素(简称AHL)进行分离提纯,通过定量31P-NMR及木质素衍生化后的还原降解(DFRC)技术研究分离得到的水解残渣木质素的官能团的含量。采用TG和DTG研究AHL的热分解特性。借助Py-GC-MS分析AHL热裂解产物的主要组成。研究结果表明,AHL的热解发生在一个宽泛的温度范围内,并且DTG曲线中可以看到两个明显的失重峰;AHL热裂解产物主要由木质素大分子β-O-4连接断裂所得产物及二次裂解产物构成。

Physical and chemical properties of wood fiber hydrolysis residue in typical hydrolysis process were studied. The acid hydrolysis lignin （AHL） was separated and purified. The content of functional groups in AHL was defined by 31P-NMR analysis and DFRC method. Pyrolysis characteristics of AHL were studied with thermal analyzer using TG and DTG curves. The pyrolysis products of AHL were studied with Py-GC-MS. The results have shown that the pyrolysis of AHL is observed in a wide temperature range and there are two obvious peaks in DTG diagram; disconnections of macro- molecular structures based on β-O-4 linkage are indicated and multiple pyrolysis fragments are seen as the main pyrolysis products of AHL.