1. Enhancing the antioxidant activity of technical lignins by combining solvent fractionation and ionic-liquid treatment
- Author
-
Majira, Amel, Godon, Blandine, Foulon, Laurence, van der Putten, Jacinta C., Cezard, Laurent, Thierry, Marina, PION, Florian, Bado-Nilles, Anne, Pandard, Pascal, Jayabalan, Thangavelu, Aguié-Beghin, Véronique, Ducrot, Paul Henri, Lapierre, Catherine, Marlair, Guy, Gosselink, Richard J. A., Cottyn, Betty, and Baumberger, Stéphanie
- Subjects
antioxidants ,biorefinery ,green chemistry ,ionic liquids ,lignins ,antioxydant ,chimie verte ,lignine - Abstract
A grass soda technical lignin (PB1000) underwent a process combining solvent fractionation and treatment with an ionic liquid (IL), and a comprehensive investigation of the structural modifications was performed by using high-performance size-exclusion chromatography, P-31 NMR spectroscopy, thioacidolysis, and GC-MS. Three fractions with distinct reactivity were recovered from successive ethyl acetate (EA), butanone, and methanol extractions. In parallel, a fraction deprived of EA extractives was obtained. The samples were treated with methyl imidazolium bromide ([HMIM]Br) by using either conventional heating or microwave irradiation. The treatment allowed us to solubilize 28 % of the EA-insoluble fraction and yielded additional free phenols in all the fractions, as a consequence of depolymerization and demethylation. The gain of the combined process in terms of antioxidant properties was demonstrated through 2,2-diphenyl-1-picrylhydrazyl (DPPH.) radical-scavenging tests. Integrating further IL safety-related data and environmental considerations, this study paves the way for the sustainable production of phenolic oligomers competing with commercial antioxidants.
- Published
- 2019