TGA, DSC and DFT Studies of TKX-50, ABTOX and Their Key Precursors

摘要

TKX-50 (Dihydroxylammonium 5,5’-bistetrazolate-1,1’-dioxide) and ABTOX (Diammonium salt of 5,5’-bistetrazole-1,1’-diolate) being simple and cheap to prepare from commonly available chemicals, are emerging as promising energetic materials along with the advantages like required thermal insensitivity, low toxicity and safe handling. In order to synthesize such powerful materials with utmost care, it is essential to know about the precursors and reaction intermediates involved. Therefore, the detailed thermal analyses of various precursors such as glyoxime (I), dichloroglyoxime (II), diazidoglyoxime (III) and bistetrazoledihydroxide (IV) and final products viz., TKX-50 (V) and ABTOX (VI) were carried out using differential scanning calorimetric and thermal gravimetric analysis experiments. The relative trend of band gap values calculated from the difference of HOMO and LUMO is well correlated with the decomposition temperatures (Tmax) values at a heating rate of 10°C min~(1) indicating the relative thermal stability of I–VI. The impact and friction sensitivity of ABTOX and TKX-50 indicated that these compounds are safer than the currently known powerful explosives such as CL-20. The calculated density impulse of TKX-50 in rocket propellant formulations was found to be 499 g m~(-2) s~(-1) which is similar as that of HMX (494 g m~(-2) s~(-1)). The theoretical performance prediction of TKX-50 as the potential ingredient in gun propellant formulations indicated that the TKX-50 could yield higher force constant (1471 J K~(-1)) in comparison to currently known explosive such as RDX (1412 J K~(-1)).