PHYSICO-CHEMICAL CHARACTERIZATION OF HEMICELLULOSES OBTAINED BY IODINE-COMPLEX PRECIPITATION FROM POPLAR
The dewaxed cell walls of poplar (Populus gansuensis) were delignified with NaClO2 and then sequentially extracted with 0.25, 0.5 and 1.0 M KOH under a solid to liquid ratio of 1: 25 (g﹒mL-1) at 25 oC for 10 h. The successive treatments together resulted dissolution of 83.7％ of original hemicelluloses. The released hemicelluloses were separated into linear and branched hemicellulosic subfractions by the iodine-complex precipitation technique. Their chemical and physical characteristics were determined by HPAEC, GPC, FT-IR, 1H, 13C NMR and HSQC. Neutral sugar composition and molecular weight analysis showed that the hemicellulosic sub-fractions precipitated with aqueous potassium iodide-iodine had lower overall uronic acid/xylose (Uro/Xyl) ratios and higher molecular weights (Mw) than those remaining in the solution. FT-IR, 1H and 13C NMR spectroscopy analysis indicated that the alkali-soluble hemicelluloses of P. gansuensis had a structure composed of the (1→4)-linked β-D-xylopyranosyl backbone with 4-O-methyl-α-D-glucuronic acid attached to O-2 of the xylose residues.
Populus gansuensis hemicelluloses fractionation iodine-complex precipitation
Peng Feng Bian Jing Ren Junli Xu Feng Peng Pai Sun Runcang
State Key Laboratory of Pulp and Paper Engineering,South China University of Technology, Guangzhou,5 Institute of Biomass Chemistry and Technology,Beijing Forestry University, Beijing, 100083, China State Key Laboratory of Pulp and Paper Engineering,South China University of Technology, Guangzhou,5
国际会议
广州
英文
105-108
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）