In:
chemistry of plant raw material, Altai State University, , No. 1 ( 2017-12-06), p. 29-36
Abstract:
Sulfation of birch wood xylan by sulfamic acid in N,N-dimethylformamide (DMF) in the presence of urea was studied for the first time. The effect of the duration of sulfation of xylan with a mixture of sulfamic acid–urea in DMF on the yield and substitution degree of xylan sulfates was studied. The sulfur content in the obtained samples was determined using chemical method. It was found, that the degree of substitution in the obtained xylan sulfates was in the range from 1.30 to 1.64 at sulfation for 1–2 hours. The structure of initial and sulfated xylan was investigated with the use of FTIR and 13C NMR spectroscopy methods. The introduction of sulfate groups into the structure of xylan was confirmed by appearance in FTIR spectra new absorption bands characteristic for the stretching vibrations n (C–O–S) at 804 cm-1, symmetric stretching vibrations ns (SO2) at 1009 cm-1, asymmetric stretching vibrations nas (SO2) at 1244 and 1260 cm-1.Studying of 13C NMR spectrum of the obtained xylan sulfates showed that there was partial substitution of hydroxyl groups at С2 and С3 positions of anhydroxylose units of xylan.
Type of Medium:
Online Resource
ISSN:
1029-5143
,
1029-5151
DOI:
10.14258/jcprm.2018012268
Language:
Unknown
Publisher:
Altai State University
Publication Date:
2017
detail.hit.zdb_id:
2195031-3
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