Preparation and sensitivity of mixture explosive of polymer bonded ε-HNIW

In order to improve the crystalline quality of raw hexanitrohexaazaisowurtzitane(CL-20) and meet the insensitivity requirement in formulations of mixed explosives, ε-CL-20 grains obtained by re-crystallization were coated by using an aqueous suspension technology. The results showed that raw CL-20 grains weren t coated directly because of multi-forms of crystal structure, inhomogeneous size distribution and high mechanical sensitivity (level approaching that of raw PETN). The pure ε-CL-20 crystals having regular morphology and uniform particles were prepared from ethyl acetate and petroleum ether. With the use of back-extraction crystallization at room temperature, high quality ε-CL-20 crystals having lower impact sensitivity than that of raw CL-20 were obtained. Three typical binders were selected to coat e-CL-20 crystals. It was found that stearic acid (SA) was better than 3-polybutadiene rubber(BR) and EVA when the mass percentage of binders was fixed at 5%. The characteristic drop height of impact sensitivity of ε-CL-20/SA moulding power was 24.46 cm (2.5 kg hammer), closing to that of 1 class RDX. The thermal characteristics of ε-CL-20/SA(95/5) were studied using thermal analytical technique DSC-TG at 5'C/min, showing that the initial and peak temperatures for the decomposition of ε-CL-20/SA were at 238.8°C and 242.9°C, which were higher than those of LX-19, and the mixture of e-CL-20 and SA had a good compatibility.