Optimization of ethanol-extracted lignin from palm fiber by response surface methodology and preparation of activated carbon fiber for dehumidification

Table 6 FTIR band assignments for the lignin extracted from palm fibers

Palm mesocarp fiber lignin (Rashid et al. 2018) Band (cm⁻¹)	Palm fiber this work Band (cm⁻¹)	Peak assignment
3419	3409	O–H stretching
2935	2924	C–H stretching
2850	2840	C–H stretching (O–CH₃)
1716	1700	C–H vibration of aromatic ring
1651	1608	CH vibration of aromatic ring
1554		C=O stretching
1512	1509	Aromatic skeletal vibration
1459	1460	Asymmetric bending vibrations of methyl and methylene groups
1425		C–H in-plane bending vibration
1372		C–H bending vibration in methyl
1325	1320	Vibrations of syringyl units
1269	1269	Carbonyl stretching vibration of guaiacyl units
1034	1033	C–O deformations of aliphatic groups