In the FT-IR spectrum of HHAC, peaks at 3400–3700 cm−1 band
arise from free OH groups. Peaks visible at 1700–1900 cm−1 band
and 1600–1800 cm−1 band suggest presence of carboxylic acid
groups and aromatic C O, respectively, while those visible at
1400 cm−1 may be the result of C CH3, C CH2 deformation and
those at 1100–1300 cm−1 indicate C O, C OH and O H stretching