Table 3 The characteristic IR bands of prepared SAP
IR band/ cm−1 | Assignment(s) |
|---|---|
3250–3600 (s, b) | Stretching of H-bonded alcoholic –OH group |
2984–2960 (m, b) | C-H bond asymmetric stretching vibrations of CH3 group |
1735–1640 (s, b) | Stretching vibration of C = O bond in acrylate carboxyl group and overlapped with bending vibration of alcoholic –OH group (confirms successful polymerization) |
1449 (m) | C-H bond bending vibration of CH3 group |
1386 (s) &786 (w) | Stretching vibration of α–CH3 group (adjacent to carboxylate) |
1182 (m) | In-plane-deformation of C–O–C (the polymer is present in normal plane structure which deforms) |
851 (m), 959(w) and 1024(m) | Characteristic vibrational absorption bands due to > CH –CH2 − COOCH3 system |
524 and 416 (w) | Vibrations of –CH3 group coupled with skeletal structure |