Synthesis And Properties Of Bispyrazole, Triazole Energetic Salts

As the energy medium of modern weapons and equipment,energetic materials must meet the demand of high-energy-density and low-vulnerability.Unfortunately,the high energy and low sensitivity of energetic materials is usually a contradiction.Therefore,the development of new energetic materials with high energy,low sensitivity and excellent comprehensive performance is the hotspot in the field of energetic materials in recent years.Nitrogen-rich heterocyclic compounds have attracted more and more attention because of their unique properties,such as high heat of formation,low carbon and hydrogen contents and friendly environmental effect.Salt-based energetic materials often possess advantages over nonionic molecules,as these salts tend to exhibit lower vapor pressures,higher thermal stability and lower sensitivities than their atomically similar nonionic analogues.Moreover,the anions and cations of the energetic salts can be individually designed and modified to improve the properties of the compounds.In this thesis,we successfully designed and synthesized 1,2-bis?3,5-dinitro-1H-pyrazol-4-yl?diazene?H₂NPA?and its eight energetic salts.All compounds were fully characterized by ¹³C NMR,¹H NMR,IR and elemental analysis.Its bis?guanidinium?salt were further confirmed by single-crystal X-ray diffraction.The measured densities and decomposition temperatures of all compounds ranged between 1.70-2.15 g cm^-33 and 156-314 ^oC,respectively.Their impact sensitivity and friction sensitivity ranged between 1.5-40 J and54-360 N.The heats of formation were calculated between 45.7-1040.1 kJ mol^-1 by Gaussian software based on the designed isodesmic reactions.The detonation pressures and velocities of these compounds were calculated using EXPLO5 to be 26.0-36.6 GPa and8224-9083 m s^-1,respectively.Among them,1,2-bis?3,5-dinitro-1H-pyrazol-4-yl?diazene?H₂NPA?possesses excellent thermal stability?T_d=221 ^oC?,low friction sensitivity?FS=240 N?and it's insensitive to impact?IS=40 J?.In addition,it also shows an excellent detonation performance(v_D=9083 m s^-1,P=36.6 GPa).Therefore,it possesses the best comprehensive properties among the compounds that allow it a promising application.With a good detonation performance(v_D=8391 m s^-1,P=28.0 GPa),excellent thermal stability?T_d=305 ^oC?and insensitivity to impact and friction,the bis?guanidinium?salt has a promising application in the field of ultra-high temperature resistant energetic materials.Potassium salt possesses excellent thermal stability?T_d=314 ^oC?,high density(d=2.15 g cm^-3)and good detonation performance(v_D=8275 m s^-1,P=31.1 GPa),its impact sensitivity,friction sensitivity and electrostatic discharge were found to be 1.5 J,60 N and0.8 J;All properties of the potassium salt allow it to have a promising application in the field of highly heat-resistant,green primary explosives.In this thesis,four energetic salts of 3-nitro-1,2,4-triazol-5-one were synthesized and fully characterized by ¹³C NMR,¹H NMR,IR and elemental analysis.Its3,6,7-triamino-7H-s-triazolo[5,1-c]-s-triazole salt were further confirmed by single-crystal X-ray diffraction.All the energetic salts exhibit excellent thermal stabilities with decomposition temperatures over the range 203-270 ^oC.The measured densities of enegetic salts ranged between 1.68-1.84 g cm^-3.All energetic salts were insensitive to impact and friction except the hydrazinium salt?IS=7 J,FS=360 N?.The heats of formation were calculated between 134.4-797.7 kJ mol^-1.The detonation pressures and velocities of energetic salts ranged between 24.6-38.1 GPa and 8136-9575 m s^-1,respectively.The hydrazinium salt was found to have good thermal stability?T_d=203 ^oC?and excellent detonation velocity(v_D=9575 m s^-1),which are comparable to those of CL-20,and its impact sensitivity and friction sensitivity are better than those of CL-20.Furthermore,the hydrazinium salt can be easily synthesized and its starting materials are inexpensive.Therefore,it has a good promising application.We also prepared kilogram hydrazinium salt of 3-nitro-1,2,4-triazol-5-one?HZNTO?and its molding poweders,and studied its compatibility with some explosives,for further reseach to explore the performance of explosive and application in the field of composite explosives.