956. The kinetics of the thermal decomposition of ammonium perchlorate

Extinguishment of composite propellants at low pressures

“…However, their thermogram shows that the onset of endothermic effect occurs at a further lower temperature about 200*C. As is inferred from those works, the PU binder melts at temperatures far lower than the active AP decomposition temperature [14,15]. suggesting that this polymer also may experience melting to some degree.…”

The burning mechanism of ammonium perchlorate- based composite solidpropellants

“…It is not clear why the ash forms. It may be w59-related to Bircumshaw and Newman's (20) discoxcry that only 30% of the original AP undergoes decomposition when the temperature is below about 3500C and that the remaining 70% is unreacted solid AP, and to the fact that the surface temperature and the temperature in the ash were measured by Most(140) to be 250-300 0 C. (The granular diffusion flame theory with a collapsed A/PA flame indeed predicts a low surface temperature, about 400 0 C below 0.01 atm. )…”

“…This lattice transition occurs at 240°C (21,36) and is endothermic to the amount of 20 cal/gm (36). The transition appears to have no effect on the decomposition mechanism of AP other than to retard the rate of -5-decomposition at the transition temperature (21).…”

“…(a) Bulk Degradation of Pure AP The decomposition mechanism of ammonium perchlorate was first seriously studied by Bircumshaw and Newman (20,21). They showed the mode of degradation to depend on the prevailing pressure and temperature conditions.…”

“…Table III of Appendix B); generally, the burning rates decrease in that order also (150)(151)(152)(153). Another factor to be remembered, although probably not too important in the combustion process because of the low temperatures involved, are the solid phase transitions that occur in various crystalline substances; AP has only one transition at 240°C (20) whereas AN has four in the temperature range below 150°C (36).…”