Thermal Decomposition Kinetics Studies of Ammonium Perchlorate - HTPB /Al/AP Solid Propellants formulated with Iron Oxide burning rate catalyst in Nano and Micro scale

Abstract

The thermal decomposition kinetics of ammonium perchlorate (AP)/hydroxyl-terminatedpolybutadiene (HTPB) samples, the AP/Al/HTPB solid propellant, with Iron Oxide burning rate catalyst at nano and micro scale were studied by thermal analysis techniques at different heating rates curves in dynamic nitrogen atmosphere. The exothermic reaction kinetics was studied by differential scanning calorimetry (DSC) curves in isothermal conditions. The Arrhenius kinetics parameters were obtained by Flynn-Wall and Ozawa method. The Kissinger and Starink kinetics method was also used for obtaining the activation energy value for a comparison purpose. The propellant samples thermal decomposition was studied simultaneously by thermogravimetric and differential thermal analysis (TG-DTA). For this purpose solid propellant grains containing nano and micro scale iron oxide were formulated. The comparison was made with a solid propellant grain formulated without burn rate catalyst additive. The effect of catalysts on the propellant burning rate and the propellant initiation sensitivity were also evaluated by friction and impact. The effect of the catalyst in the propellant binder reaction was evaluated by viscosity and mechanical properties. Scanning electron microscopy with Energy dispersive analysis (SEM/EDS) techniques was used to evaluate the iron oxide morphology. Three bench firing tests were performed with rockets motor in order to konw the ballistics parameters.