“…Their FTIR spectra are shown in Figure 5. As shown in the spectrum of n -PAN, absorption bands appeared at 2928, 2240, 1736, 1454, 1360, 1240, and 1033 cm −1 , which corresponded to the stretching vibration of CH 2 , C≡N, C=O (carboxyl group in the second and third monomer), the bending deformation vibration of CH 2 , swing vibrations of CH 2 and CH, and C-O, respectively[27–29]. After the amidoximated modification, the intensity of the absorption band attributed to C≡N (2240 cm −1 ) was significantly weakened, and at the same time, new absorption bands appeared at 3700–3000, 1649, 1103, and 1933 cm −1 which were attributed to the stretching vibration of -OH and C=N, C-N in amidoxime groups, and the deformation vibration of -OH, respectively [30].…”