ABSTRACT
Ammonium nitrate (AN) and ammonium perchlorate (AP) are investigated as propellants for their thermal decomposition behaviors and burning characteristics. The performance effects of AP particle size, AP content in the oxidizer (ξ), and a catalytic amount of Fe2O3 on the propellants are evaluated. A dependency exists between the thermal decomposition behaviors of the propellants and both AP particle size and ξ. Addition of Fe2O3 further affected the thermal decomposition behaviors of the propellants; these behaviors are not dependent on the added amount. Furthermore, the burning characteristics are dependent on the AP size, ξ, and the amount of Fe2O3 added. The low-pressure ignitability of the propellants containing 2% Fe2O3 with ξ = 0.2 and 0.4 is inferior to the propellant with ξ = 0 (no AP) and the propellants containing 4% Fe2O3 with ξ = 0.2 and 0.4. An increase in 4% Fe2O3 caused a positive catalytic effect, causing an equal or higher burning rate of the propellants than that of 2% Fe2O3, except in the case of AN/AP propellants with coarse AP at ξ = 0.4 and 0.6 above 4 MPa.
Nomenclature
Chemicals
AN | = | Ammonium nitrate |
AP | = | Ammonium perchlorate |
HTPB | = | Hydroxyl-terminated polybutadiene |
Acronyms
CAP | = | Coarse AP |
DTA | = | Differential thermal analysis |
FAP | = | Fine AP |
PDL | = | Pressure deflagration limit |
TG | = | Thermogravimetry |
Symbol
R | = | Ratio of the burning rate of propellant with Fe2O3 to that of the corresponding propellant without Fe2O3 (–) |
T1 | = | Peak temperature of first decomposition (K) |
T2 | = | Peak temperature of second decomposition (K) |
χ | = | Ratio of the burning rates of propellant with 4% Fe2O3 and that of the corresponding propellant with 2% Fe2O3 (–) |
ξ | = | Mass ratio of AP to whole oxidizer (–) |