| PMMA | Collagen | Casein | |||
| Band | Bond | Band | Bond | Band | Bond |
| 2900 cm−1 | C-H | 1657 cm−1 | Amina I (N-H) | 1750 cm−1 | C=O (double) |
| 1440 - 1450 cm−1 | C-H | 1552 cm−1 | Amina II | 1650 cm−1 | Amida I (N-H) |
| 1370 - 1740 cm−1 | C=O (double) | 1241 cm−1 | Amina III | 1450 - 1550 cm−1 | Amida II N=H and C=N |
| 1200 - 1300 | C-O-C (ester) |
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