Thermal decomposition kinetics of aged solid propellant based on ammonium perchlorate - AP/HTPB binder

Resumo

The thermal decomposition of aged and non-aged samples of ammonium perchlorate(AP)/hydroxyl-terminated-polybutadiene(HTPB), the AP/HTPB solid propellant, were studied at different heating rates in dynamic nitrogen atmosphere. The exothermic reaction kinetics was studied by differential scanning calorimetry (DSC) in non-isothermal conditions. The Arrhenius parameters were estimated according to the Ozawa method. The calculated activation energies were 134.5 kJ/mol (non-aged) and 79.0 kJ mol-1 (aged), the pre-exponential factors, A, were 2.04 1010 min -1 for the non-aged samples and 1.29.106 min-1 for the aged samples and the reaction orders for the global composite decomposition were estimated in 0.7 and 0.6 (non-aged and aged samples decomposition, respectively) by the kinetic Shimadzu software based in the Ozawa method. The Kissinger method for obtaining the activation energy value was also used for a comparison purpose. These results are here discussed. © 2008 by the American Institute of Aeronautics and Astronautics, Inc.