Characterization of lignin isolated from some nonwood available in Bangladesh

摘要

Lignins isolated from cotton stalks, jute stick and dhaincha by acidolytic dioxane were characterized using alkaline nitrobenzene oxidation, elemental analysis, methoxyl analysis and molecular weight analysis and UV, IR H-1 NMR spectroscopy. The C, formulas for cotton stalks, jute stick and dhaincha (Sesbania aculeata) lignin were C9H9.36O4.50(OCH3)(1.23), C9H9.02O4.57(OCH3)(1.35) and C9H8.88O4.65(OCH3)(1.50), respectively. All three lignins were of the guaiacyl-syringyl type. Cotton stalks lignin contained more p-hydroxy phenyl unit than dhaincha and jute stick lignins as observed by alkaline nitrobenzene oxidation products. The beta-O-4 units in these nonwood lignins had predominately erythro stereochemistry type. (c) 2006 Elsevier Ltd. All rights reserved.