Isolation and Characterization of Lignins,Hemicelluloses,and Celluloses From Wheat Straw by Alkaline Peroxide Treatment

摘要

Alkaline peroxide extraction is an environmentally friendly pulping process allowing the recovery of valuable hemicelluloses and lignin products.Extarction of the dewaxed wheat straw with 2% H_2O_2-2% NaOH aqueous solution for 5 ht 45 and 50 deg resulted in a dissolution of 85% and 86% of the original lignin,75% and 76% of the original hemicelluloses,respectively,and left 53.8% and 53.3% residues with light chromoatophore,which are very suitable for paper-making,in comparison with other pulps.The two alkaline lignin fractions,two hemicellulosic preparations and the corresponding residues (mainly cellulose) were characterized by both degraded methods,alkaline nitrobenzene oxidation and acid hydrolysis,and non-destructive techniques,Ultraviolet (UV),Fourier transform infrared (FT-IR),hydrogen-1 and carbon-13 Nuclear magnetic resonance spectroscopes (~1H and ~13C-NMR) as well as Gel permeation chromatography (GPC).