Synthesis and Characterization of New Imidazolium Ionic Liquid Based Energetic Plasticizers

• Published in: Propellants, explosives, pyrotechnics explosives, pyrotechnics, 2021-10, Vol.46 (10), p.1547-1554
• Main Authors: Miri, Adel, Fareghi‐Alamdari, Reza, Nikpour, Mohsen, Hasanzadeh, Neda
• Format: Article
• Language: English
• Subjects: Differential scanning calorimetry; Energetic plasticizer; Glass transition temperature; Glycidyl azide polymer; Gravimetric analysis; Imidazolium ionic liquid; Ionic liquids; Ions; NMR; Nuclear magnetic resonance; Plasticizers; Polymer blends; Solid propellants; Thermochemical properties; Viscosity; Weight reduction
• ISSN: 0721-3115; 1521-4087
• DOI: 10.1002/prep.202000269

In the present research, two new ionic liquids (ILs) with imidazolium cation and dicyanamide anion were synthesized for their plasticizing capacity in solid propellants. The structure of plasticizers was confirmed by FT‐IR, 13C‐NMR and 1H‐NMR spectrum and their thermal behaviors were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results of the thermal analysis showed that the thermal stabilities of these ILs are suitable and the phase change curves of ILs were consistent with their weight reduction changes by increasing temperature. Moreover, the low viscosities and high densities obtained from the ILs show that these compounds could be convenient alternatives for polymeric plasticizers in propellant compositions. To understand the plasticizing effect of synthesized IL plasticizers on glycidyl azide polymer (GAP), blends of 20 % of the synthesized IL plasticizers were prepared and analysed to determine glass transition temperature and viscosity. Among all plasticizers, [Vin‐IL] [N(CN)2]‐GAP and [Me‐IL][N(CN)2]‐GAP blends produced the lowest Tg. The results of viscosity analysis show that all synthesized IL plasticizers have reduced the viscosity of the GAP binder, which indicates the plasticizing properties of ILs.