| 3330~3340 | N-H stretching |
| 2930 & 2860 | C-H stretching |
| 2270 | Isocyanate / N=C=O stretching |
| 1695~1723(H-bonded & free) | Urethane / C=O stretching |
| 1680 | PPOA / P-OH stretching |
| 1596 (used MDI) | Phenyl Ring / C=C stretching |
| 1527 (used H12MDI) | Urethane / N-H + C-N stretching |
| 1510 (used MDI) | Urethane / N-H + C-N stretching |
| 1247 (used H12MDI) | Urethane / C-N & C-O-C stretching |
| 1220 (used MDI) | Urethane / C-N & C-O-C stretching |
| 950 | H12MDI cyclohexyl -CH2- |
| 880 | Polyol / C-C-O stretching |
| 788~785 | PPO modified polyol & PPOA-PU/ P-O-C stretching |