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Analytical methods for lignin characterization II) Spectroscopical studies

Domenii publicaţii > Chimie + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: C.-M. Popescu, C. Vasile, M.-C. Popescu, Gh. Singurel, V. I. Popa, B. S. Munteanu

Editorial: Cellulose Chem. Technol., 40 (8), p.597-622, 2006.

Rezumat:

Lignin’ characterisation is a very difficult task, if considering its diversity with respect to both origin and
method of separation. The heterogeneity of lignin is caused by variations in polymer’s composition, size,
crosslinking, functional groups, and linkage type between the phenyl propane monomers (p – hydroxyl phenyl,
guaiacyl and syringyl units). The elaboration of well-defined analytical methods for lignin characterization is
very important for its industrial applications as a raw material. Two groups of lignin from woody species and
annual fibre crops have been studied by FT-IR, UV, fluorescence and 13C NMR spectroscopy. The relative
content of the different functional groups (p – hydroxy phenyl, guaiacyl and syringyl units) was appreciated by
normalised intensities and deconvolution of the spectral bands. Correlation of the results provided by these methods permits differentiation between the structural characteristics of two lignin groups from the viewpoint
of their particularities.

Cuvinte cheie: lignin, guaiacyl, syringyl, p – hydroxyl phenyl, IR spectroscopy, UV spectroscopy, 13C NMR spectroscopy, fluorescence spectroscopy