Bi-metallic nanocomposites of Mn with very high catalytic activity for burning rate enhancement of composite solid propellants

Bimetallic nanocomposites of Mn with Co, Ni and Zn were successfully synthesized by polyol method. Particles of the nanocomposites varied in shape from spherical to cubic having an average size of the order of 9–18 nm. The nanocomposites showed very high activity as burning rate catalysts for composite solid propellants (CSPs) containing hydroxyl terminates polybutadiene (HTPB) as binder and ammonium perchlorate (AP) as oxidizer. MnCo was the best catalyst among the three nanocomposites as it enhanced the burning rate of the CSP to more than three fold. Catalytic activity of the nanocomposites for thermal decomposition of AP and CSPs was investigated by simultaneous thermogravimetric analysis–differential scanning calorimetry (TGA–DSC) and ignition delay measurements. MnCo was found to be the best catalyst in terms of lowering decomposition temperature of both AP and CSPs. Kinetics of catalyzed thermal decomposition of AP was also studied using isoconversional method from isothermal TGA data.