1-Methyl-4-(8-(Nitrooxy)octyl)-1,2,4-triazolium Bis((trifluoromethyl)Sulfonyl)Imide as an Energetic Plasticizer for the HTPB/TDI System**

Graphical A new ionic liquid plasticizer [NTAZ][NTf 2 ] was synthesized. Compared with the traditional plasticizer DOA, [NTAZ][NTf 2 ] can significantly improve the energy of the propellant formulation. Energetic plasticizer is an important means to improve the energy performance of solid propellants, but there is no suitable energetic plasticizer for HTPB/TDI system. In this work, a nitrate-functionalized ionic liquid plasticizer of 1-Methyl-4-(8-(Nitrooxy)octyl)-1,2,4-triazolium bis((trifluoromethyl)sulfonyl)imide ([NTAZ][NTf 2 ]) was synthesized, and the energy was increased by the combination of nitrate functional group and 1,2,4-triazole cation. The hydrogen bond between the anion and the cation and HTPB achieves a good plasticizing effect. When 6% [NTAZ][NTf 2 ] was added to HTPB/TDI system, the glass transition temperature decreased from −63.41 °C to −64.84 °C, the tensile strength increased from 0.52 MPa to 0.79 MPa, and the storage modulus increased from 64.02 MPa to 110.32 MPa. When 4% DOA is replaced by the same amount of [NTAZ][NTf 2 ] in the HTPB formulation system, the specific impulse is increased from 261.0 s to 271.4 s. This study will guide the design and application of new energetic solid propellant plasticisers, both theoretically and experimentally.