Thermogravimetric analysis and kinetic study of 1-amino-1,2,3-triazolium nitrate

In this work the thermal decomposition and kinetics of 1-amino-1,2,3- triazolium nitrate (ATZ-NO₃) were investigated by non-isothermal thermogravimetric analyzer at various heating rates. A comparison of selected non-isothermal methods for analyzing solid-state kinetics data was presented. The result showed that the thermal decomposition process of ATZ-NO₃ consisted of two stages corresponding to the absence of amino-group, nitrate ion and the opening of triazole heterocycle, respectively. Values of activation energy (E) and pre-exponential factor (lgA) obtained by Kissinger method are 117 ± 7 kJ mol^-1, 12.40 s^-1 for the first stage and 106 ± 10 kJ mol^-1, 9.66 s^-1 for the second stage; which are constants during each decomposition stage and independent on conversion. While kinetic parameters from isoconversional methods, such as KAS method, are related to conversion closely, so isoconversional methods are more efficient in the description of decomposition mechanism. The experimental result showed that for the first decomposition stage variation of E against conversion from KAS method seemed to be negligible and the sole reaction model was established. But for the second stage the value of E obtained by KAS method changed significantly from 98 ± 11 to 115 ± 4 kJ mol-1, which indicated the complexity of decomposition reaction in the second stage.