Sulfation of wheat straw soda lignin: Role of solvents and catalysts : научное издание

Описание

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.1016/j.cattod.2021.07.033

Ключевые слова: basic catalysts, sulfamic acid, sulfation, wheat straw soda lignin

Аннотация: Sulfation of wheat straw soda lignin by the sulfamic acid–urea mixture in different solvents has been investigated for the first time. The effect of a catalyst used in the lignin sulfation process on the yield of the lignin sulfates and sulfur content in them has been explored. It has been found that the optimal medium for the lignin sulfation with sulfamic acid is dioxane and, in the presence of a catalyst, urea. Although the sulfated lignins obtained using the reaction in dimethyl sulfoxide and diglyme have the maximum sulfur contents (11.2% and 9.9%, respectively), these products are difficult to isolate and purify, which complicates the use of these solvents. Sulfated lignin obtained in the dioxane medium has a high (10.1%) sulfur content and is easy to isolate and purify. The incorporation of sulfate groups into the lignin structure has been confirmed by the infrared and nuclear magnetic resonance spectroscopy investigations. In the infrared spectra of sulfated lignin, characteristic absorption bands at 800–860 and 1260–1200 cm−1 appear. The dominant substitution of aliphatic hydroxyl groups has been confirmed by the nuclear magnetic resonance spectroscopy study. It has been found that, during the modification and purification of lignin, the latter is fractionated, which results in the redistribution of molecular weights toward the high molecular-weight region, as well as the removal of some low-molecular-weight components, which is reflected in a decrease in the number of signals in the nuclear magnetic resonance spectra.

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Издание

Журнал: Catalysis Today

Номера страниц: 1-10

ISSN журнала: 09205861

Издатель: Elsevier Science Publishing Company, Inc.

Персоны

  • Malyar Y.N. (Siberian Federal University)
  • Kazachenko A.S. (Siberian Federal University)
  • Vasilyeva N.Y. (Siberian Federal University)
  • Fetisova O.Y. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)
  • Borovkova V.S. (Siberian Federal University)
  • Miroshnikova A.V. (Siberian Federal University)
  • Levdansky A.V. (Institute of Chemistry and Chemical Technology SB RAS,Federal Research Center “Krasnoyarsk Science Center SB RAS”)
  • Skripnikov A.M. (Siberian Federal University)

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