Caractérisation de la lignine extraite de l’alfa

Written by sctunisie 30 june 2011 no comments

This paper presents a complete structural investigation of three lignin samples (crude, purified and hydrolyzed) isolated from Tunisian alfa lignin by CIMV process. Spectroscopic techniques (FTIR, NMR ¹H and ¹³C) were used for characterising the structures of these lignins. Size exclusion chromatography and MALDI-TOF/MS were employed for analysing molecular weight distribution (M_n, M_w, I_p) and identifying lignin fragments. Lignins were also characterized by determining phenolic and aliphatic groups. The results showed the presence of S-H-G-H-G, S-H-G-H, S-H-G, S-H-H, S-H and S-G oligomers incorporating mainly (β-O-4), (β-5) and (γ-O-γ) bonds. Phenolic OH fraction is higher than that of alcoholic OH.