Table 2: Assignment of the IR spectra bands of functional groups in acetylated wood flour treated with Vinegar based on acetic anhydride and ketene related work.

Band position (cm−1) Functional group

3978–3111 –OH stretching (bonded) vibrations
1718C=O stretching vibrations of acetate group
1696C=O stretching in acetyl groups
2723 and 2820C–H stretch of methylene in celluloses and hemicelluloses
2928–2904 CH3 symmetric stretch of methyl groups of aliphatic
1350–1340
(–C–CH3–) deformation of acetate group in cellulose and hemicelluloses
1254–1247( ) stretching band vibrations of the acetyl moieties and (C=O) deformation in the ester bond during acetylation
1629–1624C=C stretching of aromatic ring of syringyl in lignin
1654C=O stretching of (COOH) in glucuronic acid
1527–1509C=C Stretching of the aromatic ring caused by lignin
1044–1042
C–O stretching vibrations in cellulose, hemicelluloses, and primary alcohol
1439–1428CH2 deformation and stretching in cellulose, lignin, and xylan
625–603 C–H out-of-plane stretching absorption of aromatic ring vibrations caused by lignin