Study On The Several Energetic Compounds:Structure Design,Synthesis And Performance

In this paper,we research and develop the energetic materials with high energy and low sensitivity from three aspects:theoretical design,experimental synthesis and performance.It has been reported that the detonation performance of energetic compounds is closely related to density,heat generation,functional group,parent ring structure,hydrogen bond,oxygen balance,crystal structure and so on.On the other hand,the stability of energetic materials is also related to many factors,such as detonation heat,free space in lattice,surface potential,hydrogen bond and conjugation.The factors influence the properties of energetic compounds,which affect and restrict each other.So we studied the relationship between the molecular structure and the performance of the degsined compounds with high energy and low sensitivity.Quantum chemistry calculations and thermodynamics methods were firstly carried out to screen out novel high energy density materialsfrom several new derivatives with bicyclic structures of Cyclotrimethylene trinitramine.Their volumes,densities,heats of formation,detonation properties and impact sensitivities have been calculated with thermodynamics methods and all of these compounds exhibit good performance as HEDMs.Especially,2-1-R4 has given outstanding values as a potential HEDM.Its crystal density(2.07g/cm3),heat of detonation(1.67kcal/g),detonation velocity(10051m/s),and detonation pressure(48.5 GPa)are even higher than those of CL-20 while its impact sensitivity(h50,16cm)remains a relative safety value.Then the intermediate products of N,N'-(1,3,4,5,7,8-hexanitrooctahydro-diimidazo[4,5-b:4',5'-e]pyrazine-2,6(1H,3H)-diylide ne)dinitramide were studied with quantum chemistry methods.We found that if the ONIP is not nitrified completely,we could get several intermediate products under different degree of nitrification.Then the structures,density and some other important properties were calculated with density functional theory.The results showed that the intermediate with six nitro groups owns very good detonation performance.It may be easier to be synthetized than ONIP,and more inactive than ONIP.Based on the above study,four series of benzoheterocycle based energetic materials have been designed for screening out a strategy to improve the density and safety of the EMs.Their optimized structure and detonation properties were firstly calculated and discussed under DFT methods.After calculation,these designed explosives all showed good detonation from 7352m/s to 8788m/s.Among them,we found that the compounds with five nitro groups and one amino group have a limited performance reduction and a rapidly stability improvement.Moreover,the synthesis routes for compounds 3-1-4 were also designed.The precursor 3-1-4-0 and mononitro product 3-1-4-1 were successfully synthesized.Their 1H NMR,single crystal and elemental analysis have also been done to verify the structures.Some facile and efficient methods for the synthesis of TNPG3HA,TKX-55,and K-56 have been developed in this article.We inquired into the general law and method of their chemical technology optimum,such as,synthetic routes,solvents,temperature,time,catalytic agent and so on.In addition,some actual perforemance measurements have been taken for them.3,6-Bis(4-nitroamino-1,2,5-oxadiazol-3-yl)-1,4,2,5-dioxadiazine(H2BNOD)is used to prepare fourthree new high-energy Coordination Polymers(HE-CPs).Crystal structure analyses indicated that 1 exhibits 2D E-CP;(5-1-1a)exhibits compact 3D E-CP;2 exhibits a zigzag 1D chain structure;while the ionic salt 3 is a layer-by-layer structure(OD).Thermal analysis indicated that 1 and la exhibit good,as well as similar,thermostability(200?)owing to their compact framework structures.The enthalpy of formation is calculated from constant-volume combustion energy.The four compounds exhibit detonation velocities ranging from 7141 to 10084m/s,detonation pressures ranging from 25.10 to 58.04 GPa,and heat of detonation values from 1.11-1.91kcal/g.Two new HE-CPs,{Ag2(DNMAF)(H20)2}n(5-2-1)and {Ag2(DNMAF)}n(2)were prepared in a self-assembly strategy.Compound 5-2-1 exhibits 3D HE-CP structure with coordinated water molecules.Compound 5-2-2 exhibits compact solvent-free 3D HE-CP.Both compounds show good thermostability(decomposition temperature(Td)of 211 and 218?)and superior detonation velocities of 9673m/s and 10242m/s,detonation pressures of 50.01 GPa and 58.30 GPa,and heat of detonation of 8.16 kJ/g and 9.16 kJ/g,respectively.