Decomposition Chemistry of TAGN

Abstract Triaminoguanidine nitrate (TAGN) is a unique energetic material which produces relatively low molecular weight combustion products. TAGN is characterized by the oxidizer fragment “HNO3” that is attached by an ionic bond in the molecular structure. In this study, various types of experiments were conducted in order to elucidate the physicochemical decomposition process of TAGN. The exothermic rapid reaction observed at the early stage of the decomposition is the process representing the nature of energetics of TAGN. This exothermic reaction occurs immediately after the endothermic phase change from solid to liquid. Since the weakest chemical bond consisting in the TAGN molecule is the NN bond (159 kJ/mol), the initial bond breakage should be the amino groups and the NH2 radicals split off. The energy released by the dissociation of the NH2 radicals (104.3 kJ/mol) is the heat produced at the early stage decomposition of TAGN. Thus, the burning rate of TAGN is considered to be dominated by the dissociation of the NH2 radicals. It must be noted that the burning rate of TAGN is almost double that of HMX even though the energy contained in the unit mass of TAGN is less than that of HMX. The HNO3 attached to the molecular structure of TAGN is not the fragment to produce the exothermic rapid reaction observed at the early stage decomposition process.