One‐step preparation and characterization of insensitive HMX@PDA particles with microfluidic technology

Abstract In order to improve the security of 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX) preparation and application process, microfluidic technology was used to improve the crystal quality and surface coating in one step. Using polydopamine (PDA) as coating material, the insensitive HMX@PDA particles were prepared. The morphology, particle size and crystal form of HMX@PDA are regulated by supersaturation. When the concentration of HMX is 0.15 g ⋅ mL −1 , the flow ratio of the two‐phase solution is 1 : 1, and the total flow rate is 10 mL ⋅ min −1 , the properties of the samples were optimized to the greatest extent. At this point, the particle size of the sample was about 25 μm, SPAN value is 1.02, which is a stable β ‐HMX@PDA at room temperature. Through the test, the friction sensitivity and impact sensitivity of HMX@PDA were 36 % and 56 %, which were 52 % and 28 % lower than that of raw HMX, respectively. Meanwhile, the energy of HMX@PDA was not significantly decreased. Thermal analysis showed that PDA inhibited the β → δ crystallization process of HMX at high temperature but did not affect the thermal decomposition process of HMX. This case of preparing HMX@PDA in one‐step with microfluidic technology provides a new idea for the desensitization of energetic materials in the future.