Fabrication of microstructure-controlled CL-20-based PBX high-energy insensitive microspheres for efficient ignition suppression

High-quality coating layer is very important to reduce the ignition risk of energetic materials and inhibit the formation and propagation of hot spots. In this study, channel assembly technology (CAT) was used to achieve high-quality spherical coating of raw CL-20. The effects of different polymer content and different flow ratio on the morphology and particle size of the microspheres were studied. In addition, the internal structure, formation mechanism, crystal structure, thermal properties, mechanical properties, safety properties, detonation properties and ignition reaction evolution of the microspheres were further studied. The results show that CAT has excellent morphology control ability and process applicability. By adjusting different polymer contents and different continuous phase flow rates, the morphology and particle size of the microspheres can be controlled, and the crystal structure of CL-20 remains unchanged during the whole preparation process. CL-20/5%estane microspheres exhibited excellent monodispersity(CV < 10 %), hydrophobicity, safety, bulk density, mechanical properties and detonation properties (microspheres vs raw CL-20: 81.62 vs 68.59°; 23.5 vs 12.6 cm)(microsphere vs PM: 0.5 vs 0.0375 g/cm³; 81.2 vs 67.8 N; 38.56 vs 37.86 MPa). In addition, the high-quality coated CL-20/estane microspheres effectively inhibit the ignition of CL-20 and accelerate the quenching of hot spots, thereby improving the safety performance. This work provides a reference for the application of CL-20 and the preparation of new high-energy insensitive energetic composites.