Studies On Synthesis Of Energetic Compounds Based On Fluorodinitro-Moiety

Over the past decade,the challenges in the field of energetic materials include the search for materials with higher detonation performance and lower sensitivities towards impact and friction.The energetic materials containing fluorodinitro-moiety usually exhibit outstanding detonation properties,considerably higher thermal stabilities and lower sensitivities towards mechanical stimuli.In this paper,some energetic materials containing fluorodinitro-moiety were designed and synthesized,which is mainly consists of the following three parts:1.Studies on synthesis of energetic compounds based on fluorodinitroethylamineThe starting materials 2-fluoro-2,2-dinitroethanol was synthesized from barbituric acid through nitrification,hydrolysis,addition and fluorination reaction using selectfluor reagents.A new family of fluorodinitroethylamino compounds was synthesized from 2-fluoro-2,2-dinitroethanol and the corresponding starting materials aminoheterocyclic compounds through mannich-type reaction.The influence of the type of catalyst,reaction temperature,reaction time and solvents on the yield of products was also explored to determine the optimal reaction conditions.And all the synthesized compounds were characterized by IR?1HNMR?13C NMR spectroscopy,what's more,the structures of compounds 55 and 56 were confirmed by single crystal X-ray diffraction.The thermal stabilities of compounds 55?60 were determined by differential scanning calorimetry(DSC).The sensitivities towards impact and friction for 55?60 were measured and evaluated by using the standard BAM method.Finally,the predictive detonation properties using the EXPLOS code have been calculated.The detonation velocities of the reported compounds 55?60 lie in the range 7656?8878 m·s-1 and the detonation pressures lie in the range 22.9-35.7 Gpa,which are superior than TNT.The good detonation properties and low sensitive of these compounds suggested that this class of fluorodinitroethylamino compounds is promising potential candidate for insensitive energetic materials.2.Studies on synthesis of energetic compounds based on N-nitrated fluorodinitroethylamino compoundsFor the purpose of obtaining energetic compounds with higher detonation properties,we turned our attention to synthesis N-nitration compounds 67 and 68 by using 100%nitric acid and acetic anhydride as nitration reagent.And all the synthesized compounds were characterized by IR?1H NMR?13C NMR spectroscopy,what's more,the structures of compounds 68 was confirmed by single crystal X-ray diffraction.The thermal stabilities and mechanical sensitivities of N-nitration products 67 and 68 were tested by experimental methods,moreover,the predictive detonation properties of the compounds were calculated by using the EXPL05 code.N-nitration compounds 67(IS = 22,4 J;FS = 300 N)and 68(IS ?31.6 J;FS = 340 N)are less sensitive than RDX(IS = 7.5 J;FS = 120 N).Concerning the detonation velocities and pressures,the N-nitrated fluorodinitroethylamino 67(D 8835 m·s-1,P = 35.6 GPa)and 68(D = 8896 m s-1,P = 36.4 GPa)exhibit excellent detonation properties which are superior than RDX(D = 8763 m·s-1,P = 35.1 GPa).The favorable detonation properties and low sensitive of these compounds indicated that two N-nitrated fluorodinitroethylamino compounds 67 and 68 might be of interest for applications as insensitive energetic materials.3.Studies on synthesis of energetic compounds based on fluorodinitroethoxyA new family of fluorodinitroethoxy compounds was synthesized from 2-fluoro-2,2-dinitroethanol and the corresponding starting materials chlorinated compounds.This so-called esterification reaction mechanism was explored.And all the synthesized compounds were characterized by IR?1HNMR?13C NMR spectroscopy.Finally,the predictive detonation properties using the EXPL05 code have been calculated.The detonation velocities of the reported compounds 76?78 lie in the range 8037?8488 m·s-1,which are superior than TNT.