Cu–Cr–O nanocomposites: Synthesis and characterization as catalysts for solid state propellants

In this article we present the synthesis of Cu–Cr–O nanocomposites via a citric acid (CA) complexing approach and the evaluation of the as-synthesized Cu–Cr–O nanocomposites as additives for the catalytic combustion of AP (ammonium perchlorate)-based solid state propellants. Techniques of thermo-gravimetric/differential thermal analyzer (TG–DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM) as well as scanning electron microscopy (SEM) have been employed to characterize the thermal decomposition procedure, crystal phase, micro-structural morphologies and grain size of the as-synthesized materials, respectively. The results show that well-crystallized Cu–Cr–O nanocomposites can be produced by using a temperature as low as 600 °C. Phase structure of the as-obtained Cu–Cr–O nanocomposites depends on the Cu/Cr molar ratio in the starting reactants. Addition of the as-synthesized Cu–Cr–O nanocomposites as catalysts enhances the burning rate as well as lowers the pressure exponent of the AP-based solid state propellants considerably. Noticeably, solid state propellants containing Cu–Cr–O nanocomposites with a Cu/Cr molar ratio of 0.7 exhibits the most stable combustion at all pressures.