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Fractional characterization of hemicellulosic polymers isolated from caragana korshinskii kom / Hai-Yan Yang in Industrial & engineering chemistry research, Vol. 50 N° 11 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp.6877-6885 Titre : Fractional characterization of hemicellulosic polymers isolated from caragana korshinskii kom Type de document : texte imprimé Auteurs : Hai-Yan Yang, Auteur ; Xian-Liang Song, Auteur ; Tong - Qi Yuan, Auteur Année de publication : 2011 Article en page(s) : pp.6877-6885 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hemicellulosic  Polymers Résumé : Hemicellulosic polymers were fractionated into eight fractions by successive extractions with water, ethanol, and alkali with different concentrations from Caragana korshinskii Kom, which together accounted for 70.7% of the original hemicelluloses. The physicochemical properties of each fraction were investigated by sugar analysis, gel permeation chromatography, Fourier transform IR, 1H and 13C NMR, heteronuclear single quantum coherence, thermogravimetric analysis, and differential thermal analysis. The results showed that 4-O-methyl-α-d-glucurono-d-xylans were the dominant component in the hemicelluloses of C. korshinskii Kom. Molecular weights of the fractions ranged from 9830 to 217000 g/mol. In a comparison of all fractions, it was found that the hot water released smaller sized and more branched polysaccharides, while adding alkali as the solvent enhanced dissolution of larger-molecule-sized polysaccharides. Moreover, thermal stability analysis suggested that the hemicellulosic fraction with a low substitution degree and a large molecular weight has a slightly higher thermal stability. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016738 [article] Fractional characterization of hemicellulosic polymers isolated from caragana korshinskii kom [texte imprimé] / Hai-Yan Yang, Auteur ; Xian-Liang Song, Auteur ; Tong - Qi Yuan, Auteur . - 2011 . - pp.6877-6885. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp.6877-6885 Mots-clés : Hemicellulosic  Polymers Résumé : Hemicellulosic polymers were fractionated into eight fractions by successive extractions with water, ethanol, and alkali with different concentrations from Caragana korshinskii Kom, which together accounted for 70.7% of the original hemicelluloses. The physicochemical properties of each fraction were investigated by sugar analysis, gel permeation chromatography, Fourier transform IR, 1H and 13C NMR, heteronuclear single quantum coherence, thermogravimetric analysis, and differential thermal analysis. The results showed that 4-O-methyl-α-d-glucurono-d-xylans were the dominant component in the hemicelluloses of C. korshinskii Kom. Molecular weights of the fractions ranged from 9830 to 217000 g/mol. In a comparison of all fractions, it was found that the hot water released smaller sized and more branched polysaccharides, while adding alkali as the solvent enhanced dissolution of larger-molecule-sized polysaccharides. Moreover, thermal stability analysis suggested that the hemicellulosic fraction with a low substitution degree and a large molecular weight has a slightly higher thermal stability. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1016738