Abstract:Considering the safety problems of energetic additives and “pressure desensitization” in the engineering application of traditional emulsion explosives, hollow energetic microcapsules and hollow pressure-resistant microcapsules were developed.Hollow energetic microcapsules integrated the functions of energetic additives and sensitizers, while hollow pressure-resistant microcapsules had the functions of “self-sensitization” and “chemical sensitization”. The microstructures of hollow energetic microcapsules and hollow pressure-resistant microcapsules were characterized by scanning electron microscopy, optical microscope and laser particle size distribution analyzer. The thermal, detonation and storage stability properties of hollow energetic microcapsules sensitized emulsion explosive were characterized by thermal analysis test, explosion performance experiments and compatibility tests, respectively. The regeneration of sensitized bubbles was verified by observing compressed hollow pressure-resistant microcapsules under an optical microscopy. Results show that the hollow energetic microcapsules and hollow pressure-resistant microcapsules with spherical morphology, uniform particle size distribution, and hollow energetic microcapsules could significantly improve the detonation performance of emulsion explosive without affecting its safety and storage stability. The brisance and detonation speed of the hollow energetic microcapsules sensitized emulsion explosive are 23.20 mm and 4797 m·s-1 ,respectively. After collapse of the hollow pressure-resistant microcapsule under external pressure, the inner and outer substances will react and generate new sensitized bubbles, which avoids the pressure desensitization of emulsion explosive. Hollow functional microcapsules can effectively solve the problems of traditional additives by integrating the characteristics of sensitizers and functional additives.