Article (Scientific journals)
Impact of formic/acetic acid and ammonia pre-treatments on chemical structure and physico-chemical properties of Miscanthus x giganteus lignins
Vanderghem, Caroline; Richel, Aurore; Jacquet, Nicolas et al.
2011In Polymer Degradation and Stability, 96 (10), p. 1761-1770
Peer Reviewed verified by ORBi
 

Files


Full Text
Polym degr stability 2011.pdf
Publisher postprint (1.17 MB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
Miscanthus x giganteus; Ammonia pretreatment; Formic/acetic acid pretreatment; Lignin chemical structure; Lignin characterisation; Repolymerisation
Abstract :
[en] Miscanthus x giganteus was treated with formic acid/acetic acid/water (30/50/20 v/v) for 3 h at 107 C and 80° C, and soaking in aqueous ammonia (25% w/w) for 6 h at 60 C. The effects of these fractionation processes on chemical structure, physico-chemical properties and antioxidant activity of extracted lignins were investigated. Lignins were characterized by their purity, carbohydrate composition, thermal stability, molecular weight and by Fourier transform infrared (FTIR), 1H and quantitative 13C nuclear magnetic resonance (NMR), adiabatic broadband {13C-1H} 2D heteronuclear (multiplicity edited) single quantum coherence (g-HSQCAD). The radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) was also investigated. Formic/acetic acid pretreatment performed in milder conditions (80° C for 3 h) gave a delignification percentage of 44.7% and soaking in aqueous ammonia 36.3%. Formic/acetic acid pretreatment performed in harsh conditions (107°C for 3 h) was more effective for extensive delignification (86.5%) and delivered the most pure lignin (80%). The three lignin fractions contained carbohydrate in different extent: 3% for the lignin obtained after the formic/acetic acid pretreatment performed at 107 C (FAL-107), 5.8% for the formic/acetic acid performed at 80°C (FAL-80) and 13.7% for the ammonia lignin (AL). The acid pretreatment in harsh conditions (FAL-107) resulted in cleavage of b-O-4' bonds and aromatic C-C. Repolymerisation was thought to originate from formation of new aromatic C-O linkages. Under milder conditions (FAL-80) less b-O-4' linkages were broken and repolymerisation took place to a lesser extent. Ammonia lignin was not degraded to a significant extent and resulted in the highest weight average 3140 g mol -1. Despite the fact of FAL-107 repolymerisation, significant phenolic hydroxyls remained free, explaining the greater antioxidant activity.
Disciplines :
Life sciences: Multidisciplinary, general & others
Author, co-author :
Vanderghem, Caroline ;  Université de Liège - ULiège > Chimie et bio-industries > Chimie biologique industrielle
Richel, Aurore  ;  Université de Liège - ULiège > Chimie et bio-industries > Chimie biologique industrielle
Jacquet, Nicolas  ;  Université de Liège - ULiège > Chimie et bio-industries > Chimie biologique industrielle
Blecker, Christophe ;  Université de Liège - ULiège > Chimie et bio-industries > Technologie des industries agro-alimentaires
Paquot, Michel ;  Université de Liège - ULiège > Chimie et bio-industries > Chimie biologique industrielle
Language :
English
Title :
Impact of formic/acetic acid and ammonia pre-treatments on chemical structure and physico-chemical properties of Miscanthus x giganteus lignins
Publication date :
2011
Journal title :
Polymer Degradation and Stability
ISSN :
0141-3910
eISSN :
1873-2321
Publisher :
Elsevier Science, Oxford, United Kingdom
Volume :
96
Issue :
10
Pages :
1761-1770
Peer reviewed :
Peer Reviewed verified by ORBi
Name of the research project :
TECHNOSE project number 716757
Funders :
DGTRE - Région wallonne. Direction générale des Technologies, de la Recherche et de l'Énergie [BE]
Available on ORBi :
since 26 August 2011

Statistics


Number of views
230 (74 by ULiège)
Number of downloads
17 (17 by ULiège)

Scopus citations®
 
75
Scopus citations®
without self-citations
61
OpenCitations
 
71

Bibliography


Similar publications



Contact ORBi