Depolymerization of Rice Straw Lignin into Value-Added Chemicals in Sub-Supercritical Ethanol

Table 2

FTIR wavenumber and functional groups are present in the rice straw lignin and its depolymerization products.

Wavenumber (cm^−1)	Functional group and vibration type
3500–3100	-OH stretching
2800–3750	Asymmetric stretching and bending vibrations of C-H groups
2900–2935	-CH stretching
1604–1735	C=O stretching of carbonyl, carboxyl, and acetyl group and of xylans
1510–1605	Aromatic skeletal vibration (C=C) of lignin
1455–1465	-CH3O stretching vibration
1046–1130	-CO stretching vibration
800–833	-CH bonds in associated to aromatic rings.