Research on characteristic of walnut shell high boiling solvent lignin by chemical analysis, IR and NMR

Walnut shell high boiling solvent lignin (WHL) was prepared by high boiling solvent method, and its structural information could be obtained by using chemical composition analysis, infrared spectroscopy, and NMR spectroscopy. The C₉-formula of WHL, C₉H_8.95O_2.37(OCH₃)_0.72, was calculated by the experiment data. IR spectrum showed that the syringyl and guaiacyl groups were clearly existed in WHL. The ¹H-NMR spectrum of WHL also indicated the aliphatic and aromatic methoxyl groups with relative intensity ratio situated at 3.5-3.8 and 3.8-4.0 ppm, respectively. The β-O-4 bond and β-5 carbon-carbon linkage were found to be the major linkages between WHL units from the result of ¹³C-NMR spectrum.