Isolation and Characterization of Lignocellulosic Polymers from Wood Pulp of Khaya anthotheca

Abstract

The objective of this study was to isolate and characterize lingo-cellulosic polymers (lignin, hemicelluloses, and cellulose) from wood pulp of Khaya anthotheca. Concentrated sulfuric acid was used to isolate lignin from the other constituents, whereas for isolation of holocellulose, sodium chloride and glacial acetic acid were used and finally cellulose was separated from hemicellulose using alkaline hydrolysis in aqueous solution of sodium Hydroxide. The results have shown that the percentages of lignin, hemicelluloses, and cellulose are: 23%, 32%, and 42%, respectively. FTIR spectra of the isolated lignin, cellulose, and holocellulose have displayed their characteristic absorption bands. FTIR spectrum of lignin have displayed the characteristic aromatic (C=C) absorption band between 1500-1600 cm-1 together with other stretching and bending vibrations of –OH, -CH, -C-O functional groups. On the other hand, the FT-IR spectrum of holocellulose demonstrated the presence of the characteristic carbonyl absorption peak of hemicellulose around 1736 cm-1 with the stretching and bending absorption peaks of –OH, -CH, and -C-O. Finally, the spectrum of cellulose proved the disappearance of –C=O peak of hemicellulose and only –OH, -CH, -C-O absorption bands were appeared.