%0 Journal Article
	%A I. F. Fiţigău and  F. Peter and  C. G. Boeriu
	%D 2013
	%J International Journal of Materials and Metallurgical Engineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 76, 2013
	%T Structural Analysis of Lignins from Different Sources
	%U https://publications.waset.org/pdf/4184
	%V 76
	%X Five lignin samples were fractionated with
Acetone/Water mixtures and the obtained fractions were subjected to
extensive structural characterization, including Fourier Transform
Infrared (FT-IR), Gel permeation Chromatography (GPC) and
Phosphorus-31 NMR spectroscopy (31P-NMR). The results showed
that for all studied lignins the solubility increases with the increment
of the acetone concentration. Wheat straw lignin has the highest
solubility in 90/10 (v/v) Acetone/Water mixture, 400 mg lignin being
dissolved in 1 mL mixture. The weight average molecular weight of
the obtained fractions increased with the increment of acetone
concentration and thus with solubility. 31P-NMR analysis based on
lignin modification by reactive phospholane into phosphitylated
compounds was used to differentiate and quantify the different types
of OH groups (aromatic, aliphatic, and carboxylic) found in the
fractions obtained with 70/30 (v/v) Acetone/Water mixture.
	%P 167 - 172