速生桉木及其KP和氧脱木素浆中木素结构的变化  

Structural Change of Fast-growing Eucalyptus Lignin during KP Pulping and Oxygen Delignification

作　　者：郭三川[1] 詹怀宇[1] 罗小林[1] 程合丽[1] 付时雨[1] 柴欣生[1,2] 

机构地区：[1]华南理工大学制浆造纸工程国家重点实验室,广东广州510640 [2]乔治亚理工大学造纸研究所,美国亚特兰大ga30332

出　　处：《中国造纸学报》2009年第3期28-32,共5页Transactions of China Pulp and Paper

摘　　要：用不同方法从速生桉木及其卡伯值分别为17.1和9.5的KP和氧脱木素浆中分离木素,用常规的光谱分析和硝基苯氧化法对纯化的木素进行表征。结果表明,3种木素样品中,n(紫丁香基)∶n(愈创木基)∶n(对-羟苯基)分别为1.5∶1.0∶0.3、2.3∶1.0∶0.2和1.8∶1.0∶0.3;在硫酸盐蒸煮和氧脱木素过程中,木素中大量的β-O-4芳基醚键被破坏,羧基含量不断增加。从31P-NMR定量分析的对比研究可知,速生桉木中的对-酚羟基较三倍体毛白杨和南方松的难脱除且氧脱木素中木素发生缩合的程度较高。Fast-growing eucalyptus was cooked and oxygen delignified to kappa number 17.1 and 9.5 respectively, three lignin samples were extracted with two-stage method from wood, kraft pulp and oxygen delignified pulp. The purified lignin samples were characterized by UV, FT-IR, 31P-NMR and the alkaline nitrobenzene oxidation. Noticeable amounts of aliphatic hydroxyl, condensed phenolic hydroxyl, guaiacyl and demethylated phenolic hydroxyl, and traces of both p-phenolic hydroxyl and carboxyl were identified in three lignin samples. Nitroben- zene oxidation analysis showed that the molar ratio of S： V： H in three lignin preparations were 1.5：1.0：0. 3, 2. 3：1.0：0. 2 and 1.8：1.0：0. 3, respectively. Besides, β-O-4 aryl ether bonds in lignins were well cleaved and --COOH content increased during Kraft cooking and oxygen delignification process. It could be found from the results of 31P-NMR analysis that p-phenolic hydroxyl of eucalyptus lignin was more difficult to be removed than other species like poplar and southern pine, and the degree of condensation was also higher than the other species.

关 键 词：速生桉木 木素结构 硝基苯氧化 UV-VIS FT-IR 31P-NMR 

分 类 号：TS749[轻工技术与工程—制浆造纸工程]