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

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.