Preparation and characterization of MgAl-CuO ternary nanothermite system by arrested reactive milling and its effect on the thermocatalytic decomposition of cellulose nitrate

Nanothermites have been widely employed as an additive in explosive and propellant formulations owing to their high energy release efficiency, fast reaction rate, and enhanced performance. Their properties are closely dependent on the chemical nature of the implemented fuel/oxidizer components as well as the method used for their fabrication. Despite binary nanothermites, which contain one fuel and one oxidizer, being extensively developed and exhibiting interesting results, the exploration of ternary nanothermite systems is still scarce. Herein, MgAl-CuO ternary nanothermite was successfully prepared by the arrested reactive milling method (ARM). The product was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser granulometry, revealing that the particle size distributions of the powder samples obtained with pre-milled ingredients tend to shift to smaller sizes. On the other hand, composite films based on cellulose nitrate (NC) at different ratios of the nanothermite (5 %, 10 %, 15 %, and 20 %) were accordingly prepared and were fully characterized using different analytical techniques such as Fourier transform infrared (FTIR) and Raman spec-troscopies, XRD, SEM, oxygen bomb calorimeter, and differential scanning calorimetry (DSC). The thermal decomposition behavior of the obtained composites was further investigated using isoconversional kinetic analysis to assess the catalytic effect of the ternary nanothermite on the thermal behavior of cellulose nitrate (CN), whereas the energetic performances of the obtained nanocomposites were predicted by EXPLO5 V6.04 software. The obtained results have shown that MgAl-CuO nanothermite has a minor influence on the thermal decomposition temperature of the studied composites, while a noticeable decrease in the activation energy has been obtained for the different composites, demonstrating the catalytic effect of the nanothermite. It was revealed that NC composite supplemented with 5 % MgAl-CuO displayed the greatest heat of reaction and better energetic performance.

Automated summary

Nanothermites are widely used in explosive and propellant formulations due to their high energy release efficiency and fast reaction rate. This study successfully prepared MgAl-CuO ternary nanothermite and characterized it using different analytical techniques. Composite films based on cellulose nitrate were also prepared and fully characterized. The results showed that adding 5% MgAl-CuO resulted in the best energetic performance for the composites.