title: Purification, structural characterization, and modification of organosolv wheat straw lignin.
abstract: Biolignin, a wheat straw lignin produced by acetic acid/formic acid/water hydrolysis, was characterized by (31)P and (13)C-(1)H 2D NMR spectroscopy and by size-exclusion chromatography. Biolignin is a mixture of low molar mass compounds (Mn = 1660 g/mol) made up of S, G, and H units and of coumaric and ferulic acid units. β-5 and β-O-4 interunit linkages are partially acylated in the γ-position by acetate and p-coumarate groups. Deacylated samples with a low content of contaminants were obtained by combining alkaline hydrolysis and solvent extraction. The high phenolic OH content found by (31)P NMR reflects the presence of condensed aromatic units, such as 5-5 units. Reaction of purified lignin with ethanol and ethane-1,2-diol yielded esterified lignins much more soluble than Biolignin in common organic solvents. During this reaction, the secondary OH of β-O-4 linkages was simultaneously etherified. Phenol hydroxyethylation by 2-chloroethanol yielded samples containing only aliphatic hydroxyl groups.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Laurie
authors.initials: L
authors.lastname: Mbotchak
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Clara
authors.initials: C
authors.lastname: Le Morvan
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Khanh Linh
authors.initials: KL
authors.lastname: Duong
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Rousseau
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Tessier
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, Institut Parisien de Chimie Moléculaire UMR 8232, Chimie des Polyméres, F-75005 Paris, France.|CNRS, IPCM UMR 8232, F-75005, Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Fradet
mesh_terms: D002850:Chromatography, Gel; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D018547:Plant Stems / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D008031:Lignin
keywords: NMR; esterification; etherification; wheat straw lignin