The Kinetics of Thermal Decomposition of Hydrophilic and Hydrophobic Ionic Liquids Under Non-Isothermal Conditions

Abstract

The thermal stability and decomposition kinetics of a series of 1-alkyl-3-methylimidazolium cation-based ionic liquids with different alkyl chain lengths (propyl, butyl, hexyl, and octyl) and N-alkyl pyridinium cation based ionic liquids with different alkyl chain lengths (butyl, hexyl, octyl, and cetyl) were investigated under non-isothermal thermo-gravimetric analysis. Non-isothermal experiments were conducted from 298.15-773.15 K with a heating rate of 10K/min. The activation energies and collision factors were determined by non-isothermal analysis for the ionic liquids with the propyl, butyl, hexyl, and octyl chains (imidazolium cation-based), while for ionic liquids, butyl, hexyl, octyl, and cetyl chains in the case of pyridinium cation based ionic liquids. Furthermore, the result obtained manifested that no clear relationships were found between the alkyl chain length and the kinetic parameters.

Keywords: Ionic liquids, Menschutkin quaternization reaction, thermal analysis, the energy of activation, Collision Frequency