Influence of tailored CuO and Al/CuO nanothermites on the thermocatalytic degradation of nitrocellulose and combustion performance of AP/HTPB composite propellant

Al/CuO nanothermites have displayed unique catalytic activities in accelerating the thermolysis of nitrocellulose (NC) and combustion characteristics of AP/HTPB propellant depending on the morphology of CuO. The kinetic triplet of NC-based composites was determined by multi- isoconversional methods, whereas the reaction models were reconstructed by employing a modified Šesták–Berggren equation based on the combined kinetic analysis. DSC and TG-FTIR results revealed that CuO and Al/CuO play crucial roles in accelerating the dissociation of –O–NO2 bond and the coacervate phase to change the pyrolysis mechanism of NC from an autocatalytic reaction to a modified n-th order reaction model. It was also demonstrated that nanothermites were provided with a low starting temperature of pyrolysis, reduced exothermic peak temperature, low activation energy, and high total weight loss, confirming their better catalytic activity than their corresponding CuO, of which Al/CuO nanothermite, containing the gypsophila paniculata-like CuO, performs the best. Further, the shape of CuO was found to be significant in enhancing the burning rate of AP/HTPB propellant containing thermites, with the gypsophila paniculata-like presenting the best catalytic effect (43% improvement). Hence, introducing well-defined nanostructures is a promising way to improve the pyrolysis and combustion of energetic materials.