Frequency (cm−1) | Origin/Type of Vibration | Functional Group Assignment |
2700 - 2550 | -OH stretch of phosphonic acid; H-O-P=O | Suspected to come from H-O-P=O bonds created during the formation of Crosslinked-PPTE. |
1260/1230 | -C-O-P=O stretch of organic ( ) phosphates | As for Crosslinked-PPTE. |
1200/1100 | -P=O stretch | Ditto. |
1050/970 | -P-O-C- stretch of ( ) phosphate esters. | Ditto. |
1420 - 1100 | Aryl sulphones, organic sulphates and sulphonates demonstrate IR absorption in this region. | SO2, -SO4, etc. |
1450 - 1345 | Asymmetric stretch of the -S=O group of and | Sulphonic acid ( ) group introduced to substitute for and replace the hydroxyl hydrogens(H) of PTE-catechin in the sulphonationprocess. |
1323 - 1300 | Asymmetric stretching of O=S- of (O=S=O) sulphones | Sulphone O=S=O bond created in the sulphonation process. |
1160 - 1125 | Symmetric stretching of O=S- of O=S=O | |
1062 - 1034 | -S=O stretch of a -S-O-H | PTE-O-S-O-H created during sulphonation. |