This study used dynamic thermogravimetry and FTIR to analyze the gas phase composition before and after the pyrolysis of ionic liquids. The method proposed in literature by use of the thermal diagram of DSC and TGA to estimate the flashpoint of ILs was used and the results were compared with those obtained from flash point tester. A new proposed method by use the tested isothermal TGA decomposition rate at different temperature was tested and was used to estimate the pyrolysis kinetic parameters of ionic liquids. Finally, the estimated flashpoints of ILs were compared with the experimental data.
The flash point of ionic liquids was tested by the Flash point tester (Walter Herzog GmbH Pensky-Martens HFP 360). The decomposition behavior of ionic liquids was analyzed by the thermogravimetric analyzer (Mettler Toledo TGA/SDTA851e) and Differential scanning calorimetry (Mettler Toledo DSC821e). The FTIR Multicomponent (FTIR Gas Analyzer GASMET Dx-4015) was used to analyze gas phase composition of the pyrolysis products of ionic liquids.
The results tested from dynamic thermogravimetry and FTIR indicated that the gas phase compositions were different. It demonstrated that the estimation of flashpoint of ionic liquids from TGA decomposition data is not appropriate. The method proposed in this study by use of the pyrolysis kinetic parameters from isothermal TGA decomposition rate of ionic liquids.
The estimation of flashpoint by use of TGA decomposition data will underestimate the fire and explosion hazard of ionic liquids. By use of the kinetic parameters to estimate flashpoint of ILs proposed in this study give an accuracy result, and reduce the cost of flash point testing.
