CHARACTERIZATION OF METHYLOLATED LIGNIN BY H-NMR AND C-13-NMR

The hydroxymethylation of an ammonium based lignosulfonate (ALS) was done in the presence of alkali. In terms of their chemical structures, lignin and lignin derivatives were characterized and quantified by H-NMR and C-13-NMR spectroscopy. Results indicate that two kinds of hydroxymethyl groups can be formed in the process of lignin methylolation. One kind is adjacent to the aromatic ring, the other is adjacent to the side chain. The amount of hydroxymethyl groups increases and of aromatic protons decreases with increasing methylolation time and levels off after 3 hours.