Molecular Design And Performance Research Of High Energy Density Compounds

In this thesis,density functional theory(DFT)was used to study the electronic structure,heat of formation,crystal density,detonation performance,impact sensitivity,and thermal stability of 30 nitro energetic compounds,12 PETN-based derivatives,and 20 NG-based derivatives.And according to the standards of energy and stability,high energy density compounds(HEDC)with excellent performance are screened out.The main works of this paper are as follows:1.Using DFT-B3LYP/6-311G**method,the geometric structures of 30 kinds of nitro energetic compounds were optimized,and the isodesmic reactions were adopted to calculate their HOFs.The K-J equation was used to predict the detonation properties.The regular relationship with impact sensitivity and structure provides certain theoretical guidance for future design and screening of HEDC candidates.In future research,we can mainly focus on heterocyclic nitroamine compounds and aromatic nitro compounds.2.At the B3LYP/6-311G**level,the electronic structure,heat of formation,detonation performance,impact sensitivity,and thermal stability of 12 kinds of PETN-based derivatives were systematically studied.The results show that most of the title compounds have good detonation properties.The introduction of the-NF₂ group can improve the density,explosive heats and detonation properties of the energetic compounds.The h₅₀ value of almost all the PETN derivatives are higher than that of 1,3,5,7-tetranitro-1,3,5,7-tetrazotane(HMX).The analysis of bond dissociation energy(BDE)shows that the N-NO₂ bond is often the trigger bond in thermal decomposition.Considering both detonation performance and thermal stability,the three compounds were screened as potential HEDC candidates.3.Using the B3LYP/6-311G**method,the electronic structure,heat of formation,thermodynamic properties,density,infrared spectrum,detonation performance and impact sensitivity of 20 kinds of NG-based derivatives were systematically carried out.The detonation performance and density of most of the title compounds are higher than that of NG and their impact sensitivities are lower than that of HMX.The introduction of-NO₂ and-NF₂ groups will increase the density and detonation properties of the title compounds.The analysis of bond dissociation energy(BDE)shows that the C-NO₂ bond is easily triggered during pyrolysis.Considering both energy and stability,the five compounds were screened as potential HEDC candidates.