Preparation of HMX-based energetic microspheres with efficient self-healing function by microchannel technology to enhance storage performance and interface bonding effect

The self-healing function is considered one of the effective ways to address structural damage and improve interfacial bonding in Energetic composite materials (ECMs). However, the currently prepared ECMs with self-healing function have problems such as irregular particle shape and uneven distribution of components, which affect the efficient play of self-healing function. In this paper, HMX-based energetic microspheres with self-healing function were successfully prepared by microchannel technology, which showed excellent self-healing effect in both Polymer-bonded explosives (PBXs) and Composite solid propellants (CSPs). The experimental results show that the HMX-based energetic microspheres with different binder contents prepared by microchannel technology show regular shape, HMX crystal particles are uniformly wrapped by self-healing binder (GAPU). When the content of GAPU in HMX-based energetic microspheres is 10%, PBXs show excellent self-healing effect and mechanical safety is improved by 400% (raw HMX vs S4, 5 J vs 25 J). As a high-energy component, the burning rate of CSPs is increased by 359.4%, the time (burning temperature > 1700 °C) is prolonged by 333.3%, and the maximum impulse force is increased by 107.3% (CSP-H vs CSP-S4, 0.84 mm/s vs 3.87 mm/s, 0.06 s vs 0.26 s, 0.82 mN vs 1.70 mN). It also has excellent storage performance. The preparation of HMX-based energetic microspheres with self-healing function by microchannel technology provides a new strategy to improve the storage performance of ECMs and the combustion performance of CSPs.