Synthesis and characterization of a 1,3-dibutylimidazolium azide ([BBIm][N3]) : A promising green energetic ionic liquid

Abstract

In the pursuit of advancing imidazolium-based energetic ionic liquids (EILs), the current study is devoted to the synthesis and characterization of 1,3-dibutyl-imidazolium azide ([BBIm][N3]), as a novel member in this ionic liquids class. The chemical structure of this EIL was rigorously characterized and confirmed using FTIR spectroscopy, 1D, and 2D-NMR analyses. The thermal behavior assessment was conducted through DSC and TGA experiments. DSC analysis revealed an endothermic glass transition at Tg=–61 °C, followed by an exothermic degradation event at Tonset=311 °C. Similarly, TGA thermograms exhibited a one-stage decomposition process resulting in 100% mass loss of the sample. Furthermore, the short-term thermal stability of the azide EIL was investigated by combining the non-isothermal TGA data with the TAS, it-KAS, and VYA/CE isoconversional kinetic approaches. Consequently, the Arrhenius parameters (Ea=154 kJ·mol-1, Log(A/s-1))=11.8) and the most probable reaction model g(α) were determined. The observed high decomposition temperatures and the significantly elevated activation energy affirm the enhanced thermal stability of the modified EIL. These findings revealed that [BBIm][N3] EIL can be a promising candidate for advanced energetic material application.

Keywords

• 1,3-dibutyl-imidazolium azide [BBIm][N3]
• Energetic imidazolium-base ionic liquids
• 1D-/2D-NMR analyses
• Short-term thermal stability
• Isoconversional approaches