Deuterium isotope effects during the thermal decomposition of 1,4-butanediammonium dinitrate and selected composites with ammonium and potassium nitrates

Abstract The thermal decomposition of 1,4-butanediammonium dinitrate (BDD), selected BDD-based composites with ammonium/potassium nitrates (BAK), and specifically deuterated analogs, was investigated. A previous study showed that molten BDD decomposes thermally via a multistep process that produces a variety of condensed phase and gaseous products. The nature of the products suggested that proton transfer from cation to anion followed by C-N bond rupture occurred early in the decomposition process. During the present investigation condensed phase DSC induction period studies performed using specifically deuterated BDD analogs generally displayed inverse deuterium isotope effects. Impact sensitivities, times to explosion and critical temperatures were also determined for BDD, the BAK composites, and many of their N-deuterated analogs. While these studies did not unequivocally reveal the specific covalent bond rupture responsible for generating the conditions favorable for exothermic decomposition, they did provide a direct relationship between induction period chemistry and macroscopic thermal sensitivity properties.