Studies On The Synthesis And Properties Of New Energetic Compounds As Oxadiazoles And FOX-7-Derived Polynitrotriazinanes

Energetic materials with high energy and low sensitivity have been the research focus in the field of energetic materials in recent decades.For this purpose,researchers have done a lot of work and made good progress,synthesizing low sensitive explosives such as TATB,NTO,LLM-105 and FOX-7 et al.While the application research on them is being put into practice,developing new high-energy and low-sensitivity explosives is still an important research subject.In this paper,several series of energetic compounds with high energy and low sensitivity were designed and synthesized by optimizing the molecular structure,and their properties were investigated.It mainly consists of the following three parts:1.Studies on the synthesis and properties of 1,2,4-oxadiazole energetic derivatives1,2,4-oxadiazole was chosen as main energetic frame to make an energetic modification on it.First,1,2,4-oxadiazole-3-chlorooxime(101)was synthesized from glyoxal by multi-step reaction.Then,by using the chemical properties of oxime,a series of1,2,4-oxadiazole energetic derivatives with good comprehensive properties were obtained by introducing dinitromethyl,hydroxytetrazole and furozan into 1,2,4-oxadiazole ring.Among them,potassium salt 103 has high energy density and mechanical sensitivity,and possesses the potential to become a primary explosive.The energy levels of hydrazine salts 104 b,106b and hydroxyammonium salts 104 c,106c are comparable to that of RDX.3-[4-(1,2,4-Oxadiazol-3-yl)-2-oxido-1,2,5-oxadiazol-3-yl]-1,2,4-oxadiazole(107)shows low melting point less than 100 oC,high decomposition temperature more than 200 oC and good detonation performance,demonstrating its potential as a melt-casting explosive.2.Studies on the synthesis and properties of polynitrotriazinane energetic compounds based on gem-dinitromethylenetriazinane derived from FOX-7The energetic derivatization of hexahydro-1-tert-butyl-4-gem-dinitromethylene-1,3,5-triazine(108)was surveyed to obtain energetic compounds with excellent comprehensive properties.A series of energetic polynitrotriazinanes were synthesized by the application of "protection-deprotection" strategy,avoiding the complete nitrification of gem-dinitromethylene to unsatisfactory explosive group-trinitromethyl.Among them,the detonation velocity and detonation pressure of potassium salt 110 are as high as 9549 m s-1and 40.24 GPa,respectively.It also shows the characteristics of high density and high mechanical sensitivity.So it has great potential to become a non-heavy metal(lead-free)primary explosive with excellent performance.6-(Fluodinitromethyl)-1,3-dinitro-1,2,3,4-tetrahydro-1,3,5-triazine(112)(v D=9255 m s-1,P=41.1 Gpa)exhibits excellent detonation performance and moderate sensitivity.4-(Dinitromethylene)-1-nitro-1,3,5-triazinane(120)(?and ? polymorphs)and 4-(dinitromethylene)-1-nitroso-1,3,5-triazinane(121)maintain the low sensitivity of FOX-7.Moreover,120? and 121 show superior detonation performance to that of FOX-7,and the energy level of 120? is comparable to that of RDX.When 100% HNO3 was used as nitrating reagent,polynitro fused-ring compound4,8,10,10-tetranitro-bicyclic[4.4.0]-1,3,5,7-aza-1-decene(122)were synthesized from 108 in the presence of Zn Cl2.The thermal stability of fused-ring compound 122 is the best among all FOX-7-derived fused-ring compounds.Its explosive performance is on a par with RDX,and its sensitivity is more insensitive than RDX.In addition,its preparation method is simple without the use of dangerous intermediate H-FOX.3.Studies on the synthesis and properties of polynitrotriazinane energetic compounds based on FOX-73,4-bis-gem-dinitromethylene-1,3,5-triazinane(129),1,1'-methylene-4,4'-gem-dinitromethylene-1,3,5-triazinane(130)and 1-trinitroethyl-4-gem-dinitromethylene-1,3,5-triazinane(131)were synthesized in one-step reaction from FOX-7 as starting material.The detonation velocity and detonation pressure of compound129 are 8899 m s-1 and P=35.83 GPa,respectively,which is slightly better than those of RDX(v D=8795 m s-1,P=34.9 GPa)and FOX-7(v D=8870 m s-1,P=34.0 GPa);compound 130(v D=8332 m s-1,P=26.47 GPa)also has good detonation performance,and its thermal stability is better than most of FOX-7 energetic derivatives.Both of them inherit the low sensitivity characteristic of FOX-7.Therefore,compounds 129 and 130 are considered as low sensitive high-energy explosives with good overall performance.