The kinetics of thermal decomposition of 1-alkyl-3-methylimidazolium chloride ionic liquids under isothermal and non-isothermal conditions
| Autor: | John C. Hassler, Erdogan Kiran, Mary E. McCorkill, Michael Williams, James S. Dickmann |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Thermogravimetric analysis Chemistry Kinetics Thermal decomposition 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Chloride Isothermal process 010406 physical chemistry 0104 chemical sciences chemistry.chemical_compound Ionic liquid medicine Physical chemistry Thermal stability Physical and Theoretical Chemistry 0210 nano-technology Instrumentation Alkyl medicine.drug |
| Zdroj: | Thermochimica Acta. 685:178509 |
| ISSN: | 0040-6031 |
| DOI: | 10.1016/j.tca.2020.178509 |
| Popis: | The thermal stability and decomposition kinetics of a series of 1-alkyl-3-methylimidazolium chloride ionic liquids with different alkyl chain lengths (ethyl, propyl, butyl, hexyl, and decyl) were investigated with isothermal and non-isothermal thermogravimetric analysis. Isothermal experiments were conducted at 100, 125, 150, 175, 200, and 225 °C in nitrogen atmosphere. Non-isothermal experiments were conducted from 25−650 °C with heating rates of 5, 10, 15, and 20 ℃/min. Under both heating modes, the ionic liquids with the longer alkyl chains were found to display lower thermal stability. The activation energies E a determined from isothermal analysis ranged from 115-120 k J / m o l , except for the ionic liquid with the decyl chain, for which the value was higher (157 k J / m o l ). The E a determined by non-isothermal analysis were similar to the isothermal values for the ionic liquids with the ethyl and decyl chains, higher (144-154 k J / m o l ) for the ionic liquids with the propyl and butyl chains, and lower (98 k J / m o l ) for the ionic liquid with the hexyl chain. The pre-exponential factors ln ( A ) from isothermal analyses resulted in values in the range 25–29, which did not vary with reaction model. Non-isothermal analyses resulted in l n ( A ) values in the range 24–38, which were likewise not sensitive to reaction model. Among the models evaluated, the 3-dimensional reaction model was found to best represent both the isothermal and the non-isothermal data. No clear relationships were found between the alkyl chain length and the kinetic parameters. |
| Databáze: | OpenAIRE |
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