Preparation and characterization of CL-20/NTO/Estane5703 composite microspheres by spray drying

Abstract

CL-20/3-nitryl-1,2,4-triazole-5-one (NTO)/Estane5703 composite microspheres were prepared by a spray drying process using different processing parameters, which included the following four influencing factors: solvent type, inlet temperature, solution concentration, and flow rate of the feed solution. Scanning electron microscopy (SEM) was used to characterize the nanocomposites. The effects of the processing parameters on the morphology of the samples were investigated and discussed. X-ray diffraction (XRD) and differential scanning calorimetry were used to characterize the properties of the materials. The XRD results show that the diffraction peaks of the composite particle correspond to β-Cl-20 and NTO. The mechanical sensitivity of the microspheres was measured and analyzed. The SEM results indicated that optimal morphology was achieved when the dry gas inlet temperature, the solution concentration, and the flow rate of the feed solution were 80 °C, 10 mg ml−1, and 1.5 ml min−1, respectively, and the best solution is ethyl acetate. The thermal analysis exhibited the improved thermal stability of CL-20 in composite microspheres, whereas the impact sensitivity tests showed the enhancement of their mechanical properties. Therefore, the proposed method is an effective means of fabricating composite microspheres.