Study On The Synthesis And Performance Of New Fluorodinitroethylamine Energetic Materials

The synthesis of new energetic materials is increasingly seeking compounds with high explosive properties,low sensitivity,chemical and thermal stability.Moreover,with the synthesis of many high-energy materials,researchers are urgently required to grasp the balance between high energy and low sensitivity of energetic materials,and find ways to improve the stability of energetic materials.As an important organic intermediate for the synthesis of energetic materials,fluorodinitroethanol has a strong chemical reaction capacity and is convenient to introduce energetic molecules.It can be used to synthesize a series of fluorodinitroethyl derivatives.The introduction of fluorodinitroethyl group in the energetic molecule can improve the oxygen balance of the explosive and increase the energy of the explosive.At the same time,the presence of the fluorine atom increases the number of hydrogen bonds in the structure of the energetic molecule,which is beneficial to improve the molecular stability and reduce the sensitivity.The presence of a methylene group also enables the energetic material to have a melt-casting property.Therefore,the research on the synthesis of fluorodinitroethyl derivatives has important theoretical and practical significance.In this paper,the synthesis and nitrification process of N,N'-bis(fluorodinitroethyl)-3,4-dinitroaminefurazan(LLM-209)was optimized.Design and synthesis several other fluorodinitroethyl derivatives with fluorodinitroethanol as raw material,and their related properties were characterized.The reactivity of fluorodinitroethanol with amino groups in the heterocyclic was investigated.The research contents are mainly divided into the following three parts:(1)Synthesis of fluorodinitroethyl energetic compounds with furazan ring as skeletonThe synthesis and nitration process of LLM-209 was optimized by using fluorodinitroethanol,3,4-diaminofurazan and 3-cyano-4-aminofurazan as raw materials and design and synthesis of 3-amide-4-(fluorodinitroethylamine)furazan,the single crystal structure,Hirshfeld surface analysis,sensitivity properties and thermal stability properties of the synthesized compounds has been characterized and theoretical study of detonation properties.The results show that compared with LLM-208,the detonation performance of LLM-209 after nitrification is significantly improved,with good detonation performance(D=8981 ms-1,P=40.3 GPa,better than RDX)and good thermal stability,it can be used as an excellent high energy density explosive.(2)Synthesis of fluorodinitroethyl energetic compounds with azole ring as skeletonSuccessfully synthesized N5-(fluorodinitroethyl)-N1-methyl-5-nitroamine tetrazole and N1-(fluorodinitroethyl)-N5-aminotetrazole by using fluorodinitroethanol and 5-amino-111-tetrazole,5-amino-1-methyl-tetrazole and 1,5-diaminotetrazole as raw materials,different reaction temperatures,reagents,reaction time and feed ratio in the synthesis process was optimized,and the related structural characterization,physicochemical properties and perfonnance tests were carried out.D=8656 ms-1,P=33.1 GPa,IS=30 J,FS=320 N,its detonation performance is close to RDX,the sensitivity is low,and the overall performance is excellent.It further enriched the research and application of high energy insensitive energy-containing materials.(3)Discuss the reaction mechanism and reactivity of fluorodinitroethanol and amino derivativesThe reaction of fluorodinitroethanol with the amino group on the heterocyclic ring was discussed by analyzing the synthesis process.The possible reaction mechanism of fluorodinitroethanol with amino group was proposed,which is very important for further synthesis,advising and guide of high energy insensitive fluorodinitro compounds..Through the analysis of the crystal structure and related properties of LLM-209,the effect of fluorodinitroethyl on the properties of the compound in the molecular structure was investigated.Fluorodinitro is an important organic intermediate for the synthesis of energetic materials.The introduction of two nitro groups can improve the oxygen balance of the explosive and increase the energy of the explosive.At the same time,the presence of fluorine atoms weakens the large steric hindrance effect in the nitrate-based group,and at the same time increases the halogen in the structure of the energetic molecule.The bond and hydrogen bonding are beneficial to increase molecular stability and reduce the sensitivity of the compound.It is proved that fluorodinitro is a kind of very excellent energetic modifying group capable of synthesizing high energy and low energy energetic materials.