ISOLATION AND CHARACTERIZATION OF HEMICELLULOSE FROM CORN STOVER BY ALKALINE EXTRACTION
In this study, potassium hydroxide was used for the extraction of hemicellulose from corn stover at 75 ℃for 2 h. After that, hemicellulose was precipitated by pouring the extract into ethanol-acetic acid (9:1 v/v) with stirring, that precipitate was recovered and purified by successive washing with ethanol-water mixture. Ion chromatography (IC) was then used for characterizing the composition of the polysaccharides after extraction. The results show that the main component of hemicellulose extracted was xylan which accounts for over 75％ of the original under the conditions used. NMR and FT-IR analyses provided detailed anomeric linkage configuration and confirmed the structure of the hemicelluloses. The proposed structure of the hemicelluloses from the corn stover is an arabinoxylan mainly consisting of (1→4)-β-D-xylan backbone substituted in O-2 and/or O-3 by single α-L-arabinose residue, single α-D-glucuronic acid residue and/or short chains of sugar residues containing arabinose, xylose and galactose. In addition, the (1→4)-linked β-D-xylopyranosyl residues in the backbone may contain substituted phenolic acids. Thermal analysis suggested that the decomposition temperature of hemicellulose was 190-350℃.
hemicellulose corn stover NMR FT-IR
Cheng Heli Zhan Huaiyu Fu Shiyu
State Key Laboratory of Pulp and Paper Engineering,South China University of Technology, Guangzhou,510640, China
国际会议
广州
英文
69-72
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）