Thermal decomposition and sensitivities of RDX/SiO2 nanocomposite prepared by an improved supercritical SEDS method

Abstract

A kind of classic nanocomposite, in which nano-RDX (~60 nm) was embedded inside as the core and nano-SiO2 (~6 nm) compactly coated on its surface, was successfully prepared by an improved supercritical SEDS method. Therein, a special design of the nozzle made the fabrication realized. Analyses, such as SEM, TEM, XRD, IR, and XPS, were employed to investigate the micron morphology and structure of the nanocomposite. Thermal analysis was also conducted, and the DSC traces collected at different heating rate were obtained. Using these DSC data, we calculated the kinetic and thermodynamic parameters for thermal decomposition of raw RDX, RDX/SiO2 nanocomposite, and a simple mixture ([RDX + SiO2]), by which the characteristic of the decomposition was depicted clearly. It was confirmed that for different samples, the parameters such as E K, ΔH ≠, and T b changed remarkably. Meanwhile, the decomposition products were also probed with DSC-IR analysis. The results indicated that the main products for both raw RDX and RDX/SiO2 were CO2, N2O, and NO2. However, the detected signal intensity of NO2 for RDX/SiO2 was much stronger than that for raw RDX. In addition, testing of mechanical sensitivity disclosed that RDX/SiO2 was far more insensitive than raw RDX, and then the mechanism about this was discussed.