Synthesis, thermolysis, and solid spherical of RDX/PMMA energetic composite materials

To improve the safety of cryclotrimethylenetrinitramine (RDX), a novel method for the improvement of nano-energetic materials was reported in our research. Based on the mature microcapsule technology, nano-energetic materials are firstly fabricated by using RDX as core material and poly methyl metharylate (PMMA) as shell material via an emulsion polymerization method. The RDX/PMMA nano-composites were characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectra, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and impact sensitivity test, respectively. The SEM results indicated successful coating of the wall material PMMA on the surface of the core RDX, and the resultant particles by emulsion polymerization were regular solid spherical particles with smooth surface and dense coating layer, more importantly, it exhibits a very uniform particle size distribution with a narrower grain size. The XRD and FT-IR analyses did not show any change in the crystal structure after coating, thus indicating that PMMA could not change the crystal structure of RDX. Moreover, the characteristic height H 50 of RDX/PMMA microspheres increased from 24.3 to 39.7 cm, significantly improving the safety performance. According to the DSC analysis, the T b after core–shell coating increased by about 2 °C, and the Ea increased by 19.07 kJ mol −1 , revealing desirable thermal stability. It is obvious that the emulsion polymerization method is an effective desensitization technique to prepare core–shell composite particles for RDX.