Table 2 IR band positions recorded for Imron® FG1333, NCP H2OB and pure HDI polyisocyanurate resin (Bayhydur® 303 supplied by Bayer) and their assignment by referring to literature [22–24]
Imron® FG1333™ | NCP® H2OB | HDI isocyanurate | Intensity | Band assignment |
|---|---|---|---|---|
3330 | 3330 | 3330 | m | Secondary urethane N=H stretch/NH bonded/N–H stretching vibration band |
2930 | 2930 | 2936 | m | νa CH2 |
2860 | 2860 | 2856 | m | νs CH2 |
2270 | 2270 | 2263 | m | Isocyanate asymmetric N=C=O stretch/NCO out of phase |
1765 | 1765 | 1765 | w | Free C=O stretch |
1680 | 1680 | 1680 | vs | H bond C=O stretch/tertiary urethane C=O/C=O bonded |
1630 | 1630 | 1627 | m | Carbonyl groups in urea bonds (C=O) |
1565 | 1565 | 1574 | m | Secondary amide RCONHR′ |
1515 | 1515 | 1513 | sh | δ–NH and νa C–N |
1455 | 1455 | 1455 | vs | δ–CH2 |
1425 | 1425 | 1425 | s | δ OH |
1375 | 1375 | 1375 | m | δ–C(CH3) |
1330 | 1330 | 1334 | m | NCO in phase/CH2 |
1250 | 1250 | 1248 | m | (O=)C–O–C stretch/Urethane C–O stretch |
1155 | 1145 | 1155 | w | νa C–N–C |
1091 | 1089 | 1090 | w | νa C–O–C |
865 | 865 | 865 | w | νs C–N–C |
765 | 765 | 765 | s | C–N skel str |
730 | 730 | 730 | m | CH2 in phase rock |