摘要
用二氧化铅电极对竹类碱木素的碱性水溶液进行电化学氧化。根据氧化前后甲氧基含量及其红外光谱（IR）和核磁共振氢谱（1H－NMR）分析表明，二氧化铅电极的电氧化能脱除甲氧基，氧化醇羟基，破坏芳香环，使其羧基含量增加，而酚羟基的含量随氧化时间的延长有一个增加到减小的过程。凝胶色谱法（GPC）测量的结果表明，碱木素在氧化过程中，分子量分布变化很大，其平均分子量随着氧化时间的延长而先增高后降低，表明氧化过程中，同时发生了聚合反应和降解反应。用色谱质港联用仪（G－MS）检测到了降解产生的四种脂肪族化合物，没有得到芳香族的低分子化合物。
The electrochemical oxidation of alkaline solutoin of Bamboo alkali lignin in adiaphragm-free cell at the temperature of 3OC using a lead dioxide anode was investigat-ed. The contents of methoxyl group (determlnated by Zeisel method) and the IR, 1H-NMR spetra were anlysized, and it shows that demethoxylation and destruction of aro-matic rings occurred in the process of oxidation. Along with the increasing of electrolyt-ic time, the content of aliphic hydroxyl group decreases and that of the phenolic hydroxylgroup increases first and then declines. The curve of molecular weight distribution (de-temlned by GPC rnethod) of oxidated lignin was remarkbly changed, and the averagemolecular weights (M. and M.) rose first and then declined indicating that polymeriza-tion and degradation occurred at the same time. Four kinds of low molecular aliphisticcompounds were obtained by GC-MS methods, but no aromatic ones were found , imply-ing that the aromatic structure in Bamboo alkali lignin can be easily destructed under theconditions employed in this study.
出处
《纤维素科学与技术》
CAS
CSCD
1997年第3期41-46,共6页
Journal of Cellulose Science and Technology
