Synthesis, characterization and thermal studies on furazan- and tetrazine-based high energy materials

This paper reports the synthesis of high energy materials (HEMs) viz. 3,3'-diamino-4,4'-azoxyfurazan (DAAF), 3,3(x')-azobis(6-amino-1,2,4,5-tetrazine) [DAAT] and 1,4-dihydrazino tetrazine (DHTz). The products obtained were characterized by IR, H-1 NMR, C-13 NMR and mass spectra. Thermolysis of these compounds carried out by applying TG-DTA and DSC techniques indicated that the thermal stability of DAAF and DAAT was in the temperature range of 230-250 degreesC, whereas that of DHTz was up to similar to140 degreesC. TG-FTIR of gaseous products of these compounds suggests the evolution of NH2CN/NH3 and HCN as major decomposition products. The impact and friction sensitivity data revealed that DAAF is insensitive to mechanical stimuli whereas DAAT and DHTz are vulnerable to impact stimuli. The cyclic voltammetric studies brought out that, DAAF, DAAT and DHTz are electroactive compounds and thereby can be detected at even low concentration at pH7 and 13. The theoretical predictions of explosive power of DAAF, DAAT and DHTz alone and their combinations with well-known insensitive high explosives using Becker-Kistiakowsky Wilson (BKW) code as well as that of propellants based on them by NASA-CEC-71 suggest their potential in specific systems. (C) 2004 Elsevier B.V. All rights reserved.