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 samples was determined using a chemical method. It was found that the degree of substitution in the xylan sulfates was in the range from 1.30 to 1.64 with sulfation for 1–2 h. 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 ν (C–O–S) at 804 cm–1, symmetric stretching vibrations νs (SO2) at 1009 cm–1, asymmetric stretching vibrations νas (SO2) at 1244 and 1260 cm–1. Study of the 13C NMR spectrum of the xylan sulfates showed that there was partial substitution of hydroxyl groups at С(2) and С(3) positions of anhydroxylose units of xylan.

中文翻译：

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木聚糖与氨基磺酸在 N,N-二甲基甲酰胺中硫酸化

首次研究了氨基磺酸在 N,N-二甲基甲酰胺 (DMF) 中在尿素存在下硫酸化桦木木聚糖。研究了在 DMF 中使用氨基磺酸-尿素混合物对木聚糖进行硫酸化的持续时间对木聚糖硫酸盐的产率和取代度的影响。使用化学方法测定样品中的硫含量。发现硫酸化木聚糖硫酸盐的取代度在 1.30 到 1.64 之间，硫酸化 1-2 小时。使用 FTIR 和 13C NMR 光谱方法研究了初始和硫酸化木聚糖的结构。通过 FTIR 光谱中出现的新吸收带特征，在 804 cm-1 处出现伸缩振动 ν (C-O-S)，证实了将硫酸根基团引入木聚糖结构中，1009 cm-1 处的对称伸缩振动 νs (SO2)，1244 和 1260 cm-1 处的不对称伸缩振动 νs (SO2)。木聚糖硫酸盐的 13C NMR 谱研究表明，在木聚糖的羟基糖单元的 С(2) 和 С(3) 位置存在部分羟基取代。