Lignin and other aromatic substances released from spruce wood during pressurized hot-water extraction, Part 2: Structural characterization

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Ivan Sumerskiy, Andrey Pranovich, Bjarne Holmbom, Stefan Willför
Förläggare: TAYLOR & FRANCIS INC
Publiceringsår: 2015
Tidskrift: Journal of Wood Chemistry and Technology
Tidskriftsakronym: J WOOD CHEM TECHNOL
Volym: 35
Nummer: 6
Artikelns första sida, sidnummer: 398
Artikelns sista sida, sidnummer: 411
Antal sidor: 14
ISSN: 0277-3813
eISSN: 1532-2319


Abstrakt

Extraction of ground spruce sapwood with pressurized hot water in an accelerated solvent extractor (ASE) at 170 degrees C during 20, 60, and 100 min resulted in isolation of galactoglucomannans and aromatic substances, including lignin. The isolated lignin preparations were characterized by spectrometric (UV, FT-IR, H-1 NMR, liquid and solid-state C-13 NMR), chromatographic (RP-HPLC, HP-SEC, GC-FID, and GC-MS), conventional pyrolysis, thermally assisted hydrolysis, and methylation techniques in tandem with GC-MS, and classical wet chemistry (methoxyl groups, total and phenolic hydroxyl groups, derivatization followed by reductive cleavage-DFRC). The content of beta-O-4 bonds in isolated lignins was similar to that in MWL and their proportion decreased with extraction time. The oxidation of isolated lignins and content of total hydroxyl groups were significantly increased with extraction time. The lignin structure underwent condensation and demethylation reactions during hot-water extraction. The induction of new phenylcoumaran substructures was proposed in isolated lignins.


Nyckelord

Functional groups, hot-water extraction, lignin characterization, spruce wood, structural chemical analysis

Senast uppdaterad 2019-07-12 vid 02:48