Ethyl Oleate and Ethyl Elaidate Ozonides: Thermal Decomposition and Photolysis
Cataldo, F
| HERO ID | 4248528 |
|---|---|
| In Press | No |
| Year | 2015 |
| Title | Ethyl Oleate and Ethyl Elaidate Ozonides: Thermal Decomposition and Photolysis |
| Authors | Cataldo, F |
| Journal | Ozone: Science and Engineering |
| Volume | 37 |
| Issue | 5 |
| Page Numbers | 431-440 |
| Abstract | Highly pure ethyl oleate and ethyl elaidate were ozonized to their secondary ozonides (respectively EO-SOZ and EE-SOZ). The decomposition enthalpies of EO-SOZ and EE-SOZ were determined by DSC (Differential Scanning Calorimetry) and found, respectively, at --266 kJ/mol and --264 kJ/mol, a value much closer to the theoretically calculated upper limit of --278 kJ/mol than the decomposition enthalpy of --243 kJ/mol measured on EO-SOZ prepared from an ethyl oleate sample conforming to the European Pharmacopoeia. Although a considerable amount of heat was liberated, EO-SOZ and EE-SOZ cannot be defined as explosive based on their DSC traces at a heating rate of 10 degrees C/min. Pure EO-SOZ and EE-SOZ show a decomposition peak at the DSCs of 137 degrees C and 139 degrees C, respectively. The thermal decomposition of EO-SOZ and EE-SOZ was studied also by FT-IR spectroscopy showing that the decomposition involves the loss of the ozonide infrared band at 1110 cm(-1) and the formation of the expected decomposition products (pelargonic acid, pelargonaldehyde, ethyl azelate, etc.). The kinetics of the photochemical decomposition of EO-SOZ and EE-SOZ were studied by FT-IR spectroscopy, and the relative rate constants were determined. EO-SOZ when overozonized forms a spin adduct with nitrosobenzene and the relative nitroxyl radical was clearly detected by the Electron Spin Resonance (ESR). Secondary ozonation products known as trioxides may be responsible for these adducts. |
| Doi | 10.1080/01919512.2015.1027811 |
| Wosid | WOS:000364951200006 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | Decomposition Enthalpy; DSC; ESR; FT-IR; Ethyl Oleate Ozonide; Ethyl Elaidate Ozonide; Photolysis; Thermochemistry |