Preparation and characterization of nano-Ε-CL-20/Estane explosive

To control the crystal form of hexanitrohexaazaisowurtzitane (CL-20) and reduce the mechanical sensitivity, nano-Ε-CL-20/Estane particles were prepared by the suspension spray method with polyurethane elastic fibre (Estane) as coating agent. The particle morphology, particle size, crystal type, thermal stability and impact sensitivity of samples were characterized by scanning electron microscopy (SEM), laser particle size analyzer, transmission electron microscope (TEM), X-ray diffraction (XRD), and different scanning calorimetry (DSC) and mechanical sensitivity test. Results show that the Estane can be successfully coated on the CL-20 crystal surface and its particles are ellipsoidal or spherical with mean diameter of 456.3 nm. The CL-20 crystal form is still Ε phase. The critical temperature of thermal explosion of raw CL-20, Ε-CL-20/Estane made by aqueous suspension method and Ε-CL-20/Estane made by suspension spray drying method is 224.57, 228.65℃ and 229.87℃, respectively. Compared to water slurry method, the impact sensitivity of Ε-CL-20/Estane is reduced. The characteristic drop height is increased from 35.80 cm to 41.30 cm. © 2015, Institute of Chemical Materials, China Academy of Engineering Physics. All right reserved.