Study on Desensitization Characteristics of ε‐CL‐20 With Single‐Layer or Double‐Layer Coating Structures Prepared by Water‐Slurry Coating Method Using Various Binders and Desensitizers

ABSTRACT 2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) has a higher energy density and is expected to replace traditional nitramine explosives RDX and HMX as the preferred energetic ingredient in the formulation design of mixed explosives and solid propellants. However, CL‐20 is very sensitive during processing, handling, and storage, which significantly limits its application. This study mainly explored the desensitization characteristics of ε‐2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (ε‐CL‐20) with single‐layer or double‐layer coating structures prepared by the water‐slurry coating method using various binders and desensitizers. The binders used included Viton A, CAB, Estane 5703, and ethylene‐vinyl acetate copolymer (EVA), and the desensitizers used included paraffin wax (PW) and stearic acid. The prepared samples were characterized by scanning electron microscopy, simultaneous thermogravimetry‐differential scanning calorimetry, a bomb calorimeter, and a vacuum stability tester. In addition, their sensitivities were measured using BAM fallhammer, friction sensitivity tester, and small‐scale electrostatic spark sensitivity tester, and compared with uncoated ε‐CL‐20. The results indicated that the four series of CL‐20‐based PBX samples with a double‐layer coating structure were superior to those with a single‐layer coating structure. In addition, the ε‐CL‐20 with a double‐layer coating structure consisting of an inner layer of PW and an outer layer of Estane 5703 and ε‐CL‐20 with a double‐layer coating structure consisting of an inner layer of PW and an outer layer of EVA were recommended for use because they exhibited better performance.