Formation and chemical structures of acid-soluble lignin I: sulfuric acid treatment time and acid-soluble lignin content of hardwood

Citation
S. Yasuda et al., Formation and chemical structures of acid-soluble lignin I: sulfuric acid treatment time and acid-soluble lignin content of hardwood, J WOOD SCI, 47(1), 2001, pp. 69-72
Citations number
8
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
JOURNAL OF WOOD SCIENCE
ISSN journal
1435-0211 → ACNP
Volume
47
Issue
1
Year of publication
2001
Pages
69 - 72
Database
ISI
SICI code
1435-0211(2001)47:1<69:FACSOA>2.0.ZU;2-Y
Abstract
To elucidate the formation mechanism of acid-soluble lignin (ASL) formed in the Klason lignin determination, beech wood meals were treated with sulfur ic acid (SA) under various conditions, and the ASL solution was extracted w ith CHCl3. The results indicated the following: (1) wood components yieldin g ASL are dissolved in 72% SA during the initial stage: (2) the quantity of ASL is highest during the initial stage, then decreases with prolonged tim e of 72% SA treatment and finally reaches a constant value; (3) soluble lig nin prepared by 72% SA treatment and subsequent standing in 3% SA again yie ld insoluble Klason lignin and ASL after boiling in 3% SAI and (4) about ha lf the amount of ASL is dissolved in CHCl3. The foregoing suggest that wood components yielding ASL are dissolved in 72% SA at the beginning and final ly change to ASL after being subjected to depolymerization, hydrolysis, and other reactions. ASL may thus be composed of low-molecular-weight degradat ion products and hydrophilic derivatives of lignin.