Compatibility and thermal decomposition mechanism of nitrocellulose/Cr2O3 nanoparticles studied using DSC and TG-FTIR

Nano metal oxides are common combustion catalysts for enhancing the burning rate of solid propellants. Cr 2 O 3 nanoparticles (NPs) are efficient combustion catalysts for the pyrolysis of energetic components. In this study, Cr 2 O 3 NPs were synthesized via a modified sol-gel method and further used for studying the thermal decomposition of nitrocellulose (NC). Differential scanning calorimetry (DSC) and thermogravimetry-Fourier-transform infrared spectroscopy (TG-FTIR) analyses indicate that the Cr 2 O 3 NPs can be safely used with NC and the mechanism of the reaction between Cr 2 O 3 /NC and pure NC follows the Avrami-Erofeev equation: f ( α ) = 3(1 − α )[−ln(1 − α )] 1/3 /2. The peak temperature and activation energy ( E a ) for the thermal decomposition of Cr 2 O 3 /NC are lower than those of pure NC. NO 2 was detected at a lower temperature after NC was mixed with Cr 2 O 3 NPs; this indicated the catalytically accelerated bond cleavage of NC by Cr 2 O 3 NPs. Cr 2 O 3 have good compatibility with nitrocellulose and catalyze decomposition of NC through decrease the activation energy. The mechanism showed Cr 2 O 3 can accelerate the O-NO 2 bond cleavage and speed up the secondary reaction.