Synthesis And Studies Of Nitrogen-rich Energetic Compounds Based On Nitropyrazole Fusing Triazole

Nitrogen-rich energetic compounds have the advantages of high density,positive enthalpy of formation,high thermal stability and low sensitivity,etc.Due to the relatively high nitrogen content in their molecules,large amounts of N₂ and H₂O are mainly generated after the explosion,which has little environmental pollution.Therefore,it has always been a hot topic of research on high-energy-density compounds?HEDC?.In this paper,by optimizing the molecular structure,a class of energetic compounds based on nitropyrazole bis?1,2,4-triazole?were designed and prepared.Their structures and performances were further studied.The research content was mainly divided into the following two parts:1.Studies of synthesis and properties on the energetic compounds based on nitropyrazole fused bis?1,2,4-triazole?The tricyclic compound 4-nitro-3,5-bis?1H-1,2,4-triazol-3-amino?-1H-pyrazole with symmetrical structure was successfully prepared from 3,5-dimethylpyrazole commercially available through five steps of reaction.The amino group was then converted into nitramine group and nitro group by nitrification and oxidation reactions respectively to increase its density and detonation performance.Their structures were characterized and confirmed by ¹H,¹³C,IR and DSC.The detonation performance of these compounds were predicted by theoretical calculations.The mechanism of reaction between ester and aminoguanidine salt to form 1,2,4-triazole ring was analyzed and the low sensitivity of dinitramine compounds 6 was explained by electrostatic balance theory.2.Studies and synthesis of the nitrogen-rich energetic salts based on4-nitro-3,5-bis?1H-1,2,4-triazol-3-nitramino?-1H-pyrazoleA series of new nitrogen-rich energetic ion salts?8-17?featuring4-nitro-3,5-bis?1H-1,2,4-triazol-3-nitramino?-1H-pyrazole were synthesized by facile deprotonation or metathesis reactions with different nitrogen-rich bases or salts.Structural characterization,safety performance testing and theoretical calculation of detonation performance were performed on these ionic salts..The results show that the thermal stabilities have been greatly improved after the formation of energetic salts.Among them,hydrazine salt8 has the most outstanding comprehensive properties,so it has a great application prospect in the field of high-energy and insensitive explosive materials.