ESR STUDY OF LIGNIN MODEL COMPOUNDS IRRADIATED BY UV (254NM PHOTONS) IN THE PRESENCE OF HYDROGEN-PEROXIDE

Authors
SUN YP YATES B ABBOT J CHEN CL
Citation
Yp. Sun et al., ESR STUDY OF LIGNIN MODEL COMPOUNDS IRRADIATED BY UV (254NM PHOTONS) IN THE PRESENCE OF HYDROGEN-PEROXIDE, Holzforschung, 50(3), 1996, pp. 233-236
Citations number
10
Categorie Soggetti
Forestry,"Materials Science, Paper & Wood
Journal title
Holzforschung → ACNP
ISSN journal
00183830
Volume
50
Issue
3
Year of publication
1996
Pages
233 - 236
Database
ISI
SICI code
0018-3830(1996)50:3<233:ESOLMC>2.0.ZU;2-H
Abstract
ESR spectra of acetovanillone and trans-ferulic acid, lignin model com pounds, were measured in aqueous solution at different pH values under UV (254 nm photon) irradiation with or without hydrogen peroxide. The intensity of radicals in the irradiated samples was strongly dependen t on the concentration of both sodium hydroxide and hydrogen peroxide. Ionization of the phenolic hydroxyl group in the model compounds play s an important role in the formation of phenoxyl radicals under the UV irradiation. The presence of hydrogen peroxide enhanced the formation of phenoxyl radicals in the alkaline pH.