| Sample | O-H stretching (cm−1) | C-H stretching (cm−1) | C=O stretching (cm−1) | C-O stretching (cm−1) | C=O bending (cm−1) |
| PVA/PVP | 3319 | 2980 | 1624 | 1113 | 755 |
| PVA/PVP + 0.2% CuSO4 | 3317 | 2990 | 1628 | 1105 | 762 |
| PVA/PVP + 0.4% CuSO4 | 3311 | 2987 | 1629 | 1101 | 759 |
| PVA/PVP + 0.6% CuSO4 | 3311 | 2987 | 1629 | 1119 | 759 |
| PVA/PVP + 0.8% CuSO4 | 3311 | 2986 | 1629 | 1101 | 764 |
| PVA/PVP + 1.0% CuSO4 | 3311 | 2989 | 1629 | 1114 | 762 |