Table 4.
The main IR peaks of ACO and SACO and their corresponding functional groups.
| Frequency cm−1 | Assignment | Remark | |
|---|---|---|---|
| Unsulphonated Oil (ACO) | Sulphonated Oil (SACO) | ||
| - | 3464 | O–H | The traces of alcohol used in the formation of the sulphonated product |
| 3009 | - | C–H | Stretching frequency of non-conjugated unsaturation |
| 2853 | 2853 | C–H | stretching frequency of alkane |
| 1745 | 1745 | C–O | Stretching frequency of Ester |
| - | 1199 | S=O | Stretching of both sulphate and sulphonate groups. |
| 1464 | 1466 | C–H | Bending frequency of unsaturated alkene |
| 721 | 722 | C–C | Bending frequency of saturated carbon atom |