Green Extraction of Reed Lignin: The Effect of the Deep Eutectic Solvent Composition on the UV-Shielding and Antioxidant Properties of Lignin.
Int J Mol Sci
; 25(15)2024 Jul 29.
Article
in En
| MEDLINE
| ID: mdl-39125847
ABSTRACT
Lignin, the second most abundant natural polymer, is a by-product of the biorefinery and pulp and paper industries. This study was undertaken to evaluate the properties and estimate the prospects of using lignin as a by-product of the pretreatment of common reed straw (Phragmites australis) with deep eutectic solvents (DESs) of various compositions choline chloride/oxalic acid (ChCl/OA), choline chloride/lactic acid (ChCl/LA), and choline chloride/monoethanol amine (ChCl/EA). The lignin samples, hereinafter referred to as Lig-OA, Lig-LA, and Lig-EA, were obtained as by-products after optimizing the conditions of reed straw pretreatment with DESs in order to improve the efficiency of subsequent enzymatic hydrolysis. The lignin was studied using gel penetration chromatography, UV-vis, ATR-FTIR, and 1H and 13C NMR spectroscopy; its antioxidant activity was assessed, and the UV-shielding properties of lignin/polyvinyl alcohol composite films were estimated. The DES composition had a significant impact on the structure and properties of the extracted lignin. The lignin's ability to scavenge ABTS+⢠and DPPH⢠radicals, as well as the efficiency of UV radiation shielding, decreased as follows Lig-OA > Lig-LA > Lig-EA. The PVA/Lig-OA and PVA/Lig-LA films with a lignin content of 4% of the weight of PVA block UV radiation in the UVA range by 96% and 87%, respectively, and completely block UV radiation in the UVB range.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ultraviolet Rays
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Deep Eutectic Solvents
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Poaceae
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Lignin
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Antioxidants
Language:
En
Journal:
Int J Mol Sci
Year:
2024
Document type:
Article
Affiliation country:
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