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Optimization of the process of abies ethanol lignin sulfation by sulfamic acid–urea mixture in 1,4-dioxane medium
- Source :
- Wood Science and Technology. 54:365-381
- Publication Year :
- 2020
- Publisher :
- Springer Science and Business Media LLC, 2020.
-
Abstract
- The new process of abies ethanol lignin sulfation by a low-toxic mixture of sulfamic acid and urea in 1,4-dioxane medium was optimized, and the structure of sulfated ethanol lignin was studied. The process of lignin sulfation is described by a first-order equation in the temperature range 70–100 °C. The value of the rate constants is weakly dependent on the ratios of lignin and sulfating complex (sulfamic acid–urea mixture). The activation energy of the sulfation process decreases from 11.5 to 7.5 kJ/mol with an increase in the content of the sulfating complex (SC). The optimal conditions for sulfation of abies ethanol lignin with a high yield of water-soluble sulfated lignin [(100% of mass) with sulfur content of 7.9%] were found: temperature 95–100 °C, L/SC ratio 1:2.3–1:2.9, time 2 h. The composition and structure of water-soluble sulfated ethanol lignin were determined by elemental analysis, FTIR spectroscopy, two-dimensional NMR spectroscopy and gel permeation chromatography. It was shown that only alcoholic OH groups of ethanol lignin react with sulfamic acid. Sulfated ethanol lignin has a higher molecular weight and a lower degree of polydispersity compared to the initial ethanol lignin.
- Subjects :
- Ethanol
fungi
technology, industry, and agriculture
food and beverages
Forestry
macromolecular substances
Plant Science
1,4-Dioxane
complex mixtures
Industrial and Manufacturing Engineering
Gel permeation chromatography
chemistry.chemical_compound
Sulfation
chemistry
Yield (chemistry)
Urea
Sulfamic acid
Lignin
General Materials Science
Nuclear chemistry
Subjects
Details
- ISSN :
- 14325225 and 00437719
- Volume :
- 54
- Database :
- OpenAIRE
- Journal :
- Wood Science and Technology
- Accession number :
- edsair.doi...........ad0c50ad694aead017e968aa094cdeb0