Tetrazolium Nitrate Anion Based Salts as Potential Melt‐Castable Explosives

Tuning the Properties of 5‐Azido and 5‐Nitramino‐tetrazoles by Diverse Functionalization – General Concepts for Future Energetic Materials

5‐Azido and 5‐nitraminotetrazole backbones are established heterocyclic motifs in the research field of energetic materials synthesis. Despite the high energy content of the compounds, the problem with many derivatives is that their sensitivities are far too high. Functionalization of one of the ring nitrogen atoms is the aim of this study to adjust the sensitivity by inserting nitratoethyl, azidoethyl and methyl groups. In this context, derivatives of 2‐(2‐azidoethyl)‐5‐nitraminotetrazoles (2, 2  a–2  d), as well as 1‐nitrato and 1‐azidoethyl substituted 5‐azidotetrazole (7 and 10) and the methylation products of 5‐azidotetrazole (5‐azido‐1‐methyl‐tetrazole, 11 and 5‐azido‐2‐methyl‐tetrazole, 12) were prepared. The obtained nitrogen‐rich compounds were extensively characterized through multinuclear NMR spectroscopy and IR spectroscopy. The structural confinement was checked by X‐ray diffraction experiments. The pure samples (verified by elemental analysis) were investigated regarding their behavior toward friction, impact (BAM methods) and electrostatic discharge as well as heating (DTA and DSC). For all metal‐free compounds the detonation properties were computed with the EXPLO5 code using their density and heat of formation, calculated based on CBS‐4 M level of theory.

Thermal Decomposition Kinetics and Compatibility of 3,5-difluoro-2,4,6-trinitroanisole (DFTNAN)

In this paper, the thermal decomposition behavior of 3,5-difluoro-2,4,6-trinitroanisole (DFTNAN) was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG) by using different heating rates (2, 5, 10, 15 °C·min^-1). Subsequently, the kinetic and thermodynamic parameters of non-isothermal thermal decomposition of DFTNAN were calculated. The critical temperature of thermal explosion (Tb) and self-accelerating decomposition temperature (TASDT) were determined to be 249.03 °C and 226.33 °C, respectively. The compatibility of DFTNAN with a number of high explosives (cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-tetracyclo-[5.5.0.05,9.03,11]-dodecane (CL-20) and dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50)) was studied at different mass ratios using DSC. The criteria to judge the compatibility between the materials were based on a standardization agreement (STANAG 4147). The thermodynamic study results revealed that DFTNAN possessed superior thermal safety and stability. The experimental of compatibility results indicated that the mass ratios of the high explosives in the DFTNAN/RDX, DFTNAN/HMX and DFTNAN/CL-20 compositions more than 40%, 60% and 70% exhibited good compatibility, whereas DFTNAN/TKX-50 demonstrated poor compatibility.

Exploration of low-melting energetic compounds: influence of substituents on melting points

The substituent effect of low melting point compounds reduces sensitivity and improves explosive performance.