The Combustion Performance Composite Propellants Containing Azide HNIW Research

A new generation of propellants with high-energy and low characteristic signal is being developed worldwide. GAP/HNIW composite propellant plasticized with nitrates not only has considerable energy properties, but also has lower characteristic signal.NCO/OH ratio (R) and plasticization ratio of GAP composite propellant were primarily studied in this paper. The results showed that GAP composite propellant plasticized with mixed nitrates (NG/DEGDN) and cured with N-100 has better mechanical properties when R value is 1.6 and plasticization ratio is between 1.0~1.4.In order to decrease burning rate pressure exponent of GAP/HNIW propellant, cured GAP, HNIW monopropellant, HMX monopropellant and GAP/HNIW propellant are studied respectively. The results are as follows: Cured GAP, HNIW monopropellant, HMX monopropellant and GAP/HNIW composite propellant all have high burning rate pressure exponent. Catalysts can decrease their burning rate pressure exponents through adjusting their burning rates. MoO3 decreases their burning rate pressure exponents of cured GAP, HNIW monopropellant, HMX monopropellant and GAP/HNIW composite propellant from 0.814, 0.872, 0.800, 0.762 to 0.405, 0.647, 0.371, 0.561 under the pressure of 3~9MPa, respectively. Bi2O3 decreases their burning rate pressure exponents to 0.391, 0.749, 0.731 and 0.635 respectively. Catalytic mechanism is considered that: MoO3 and Bi2O3 increase their reaction rate of gas phase under lower pressure, leading to decrease the decomposition reaction of condensed phase and increase their burning rate under lower pressure. Under higher pressure they slowdown their velocities of gasification, leading to decrease their burning rates or mitigate the rising trend. So the burning rate pressure exponents decrease. Thermal analysis experiment shows that the effect of catalysts on GAP is because catalysts change GAP decomposition activation energy.Finally, characteristic signals of GAP/HNIW propellants with catalyst are estimated. The results show that MoO3 can not only improve their combustion properties, but also decrease their characteristic signals.