摘要
采用化学分析方法和FF-IR、GPC、1^H-NMR等测试技术对粉单竹（Lingnania chungii McClure）及其APMP的磨木木素进行了研究。结果表明,粉单竹木素为GSH型,并且含有较多的缩合G型单元,示性式为C9H（9.80）O（3.44）（OCH3）_（1.33）,β-O-4结构是木素的主要连接方式,另外还含有部分β-β结构和共轭酯键连接。在APMP制浆过程中,木素结构的H型和非缩合G型单元容易溶出,缩合G型和S型单元得到保留,甲氧基含量增加,酚羟基和醇羟基含量下降,β-O-4连接相对含量增加,β-β和共轭酯键连接减少,制浆后木素的分子结构受到较大程度的碎解。邻酚、邻醌类结构是竹材木素的主要发色基团,制浆后醌类结构含量有很大增加。
Milled wood lignins isolated from white powdery bamboo （Lingnania chungii McClure） and its APMP pulp were characterized using alkaline nitrobenzene oxidation, elemental analysis, molecular weight analysis and FrIR, 1^H NMR spectroscopy. The results showed that the lignin is composed of large amount of syringyl （S） and guaiacyl （G） units together with a few p-hydroxyphenyl （H） units. The C9 formulas for bamboo raw material and its APMP lignins are C9 H9. 80 O3.44 （OCH3）1.33 and C9 H9.12 O3. 06 （OCH3）1.58 respectively. The average molecular weight of APMP lignin decreases largely because of serious degradation of the original bamboo lignin during APMP pulping. Compared with original bamboo lignin, the contents of β-O-4 ether structure and methoxyl group in the lignin of the pulp increase as the H and non-condensed G units are dissolved easier than S and condensed G units during APMP pulping. Furthermore, the contents of aliphatic and phenolic hydroxyl groups are reduced. It is also concluded that the orth-phenol and orth-quinone structures are major contributor to the color of the bamboo lignin. The increase of ortho-quinone structures in the lignin of the pulp must be an obstacle to further improve the pulp brightness.
出处
《中国造纸学报》
EI
CAS
CSCD
2007年第4期5-10,共6页
Transactions of China Pulp and Paper
基金
国家973计划前期研究专项资助(项目批准号:2006CB708614)。
关键词
粉单竹
磨木木素
木素结构
White Powdery Bamboo （Lingnania chungii McClure）
milled wood lignin
lignin structure
