Influence of MnO₂ and Fe₂O₃ on the Burning Characteristics of AN/AP‐Based Composite Propellants

Abstract

The partial substitution of ammonium perchlorate (AP) for ammonium nitrate (AN) improves the burning characteristics of AN‐based propellants, because the advantages of AP propellants compensate for the drawbacks of AN propellants and vice versa. The burning characteristics of AN/AP‐based propellants supplemented with MnO2 and Fe2O3 were measured, and the effects of these catalysts on the burning characteristics of the propellants were investigated using the collected data. The ignitability and the burning rate of the AN/AP propellant was improved by the addition of MnO2. The addition of the MnO2/Fe2O3 bicatalyst improved the ignitability of the propellants compared to adding only MnO2, but the improvement was identical to that obtained using Fe2O3. The burning rate increased in the order MnO2<Fe2O3<bicatalyst. Furthermore, the effect of these catalysts on the burning characteristics was found to depend on the size of the AP particles and the type of binder.

Burning characteristics of ammonium nitrate propellant containing fine ammonium perchlorate – influence of porosity of ammonium perchlorate**

“…This is because AN‐based propellants are chlorine‐free, with low hazard and low observable emissions (minimal smoke). Numerous approaches have been adopted to improve the burning characteristics of AN‐based propellants, including the use of catalysts [3, 5–15], addition of metals [3, 16–20], and use of azide polymers [21–23] and polytetrahydrofuran [10, 24].…”

“…been adopted to improve the burning characteristics of AN-based propellants, including the use of catalysts [3,[5][6][7][8][9][10][11][12][13][14][15], addition of metals [3,[16][17][18][19][20], and use of azide polymers [21][22][23] and polytetrahydrofuran [10,24].…”

“…AN/ AP propellants are prepared using AN and AP as oxidizers; therefore, the drawbacks of AN are mitigated by the advantages of AP and vice versa. The burning characteristics of AN/AP-based propellants have been reported [5,11,13,14,[25][26][27].…”

“…Fe 2 O 3 is an effective burning catalyst for both APand AN-based propellants. The burning characteristics of AN/AP propellants with Fe 2 O 3 have been investigated in previous studies [5,[7][8][9][10][11][12][13][14][15]. Fe 2 O 3 reduces the heterogeneity of the combustion wave of AN/AP propellants [11,13,14].…”

“…The burning characteristics of AN/AP propellants with Fe 2 O 3 have been investigated in previous studies [5,[7][8][9][10][11][12][13][14][15]. Fe 2 O 3 reduces the heterogeneity of the combustion wave of AN/AP propellants [11,13,14]. Catalyst addition is a useful method for ensuring that the combustion wave structure of a propellant is not heterogeneous, as heterogeneity would result in self-quenching or unstable combustion.…”