Ballistic and thermal characterisation of greener composite solid propellants based on phase stabilized ammonium nitrate
Florin-Marian Dîrloman, Adrian-Nicolae Rotariu, Traian Rotariu, Gabriel-Flavius Noja, Raluca Elena Ginghină, Neculai-Daniel Zvîncu
Abstract
Several representatives of a new class of "greener" propellants, comprising polyurethanes (based on recycled PET) as the binder, phase stabilized ammonium nitrate (PSAN) as the eco-friendly oxidizer, and triethylene glycol dinitrate (TEGDN) as the energetic plasticizer, together with aluminium-magnesium alloy as fuel and iron oxide powder (α-Fe2O3) as the catalyst, were prepared and investigated through specific analytical tools. Besides morphological and compositional investigations, the thermal behaviour and ballistic properties of the propellants were determined, and compared to those of consecrated propellants compositions, based on ammonium perchlorate. The calorimetric tests were used to measure the heat of combustion and specific volume. Impact and friction sensitivities were also measured. The ballistic tests carried out in closed bomb and the original data processing approach used allowed, in addition to the propellant force and covolume, the identification of a critical parameter such as the power index from Vieille's law of the burning rate.