One-Step Synthesis of 2,2‘,4,4’,6,6’-Hexanitrostilbene Based on Numerical Simulation of SK Static Mixer

2,2’,4,4’,6,6’- Hexanitrostilbene (HNS) is a high-energy insensitive explosive widely used in aerospace and other fields. Its one-step synthesis typically employs a one-pot reaction method, but intermittent feeding can lead to uneven mixing and precipitation of raw materials, resulting in unsatisfactory yields and purity. To tackle these issues, this study introduced a kenics (SK) static mixer and modified the intermittent feeding method. The static mixer was simulated using ANSYS FLUENT software, and computational fluid dynamics (CFD) analysis optimized its structure, enhancing the mixing efficiency of raw materials for continuous HNS synthesis. Results indicated that after optimizing the aspect ratio (<i>L/D</i>), twist angle (<i>α</i>), and thickness (<i>b</i>) of the mixer components, the mixer demonstrated superior mixing performance. This configuration nearly doubled the yield of HNS compared to traditional methods. The product’s purity was assessed using high-performance liquid chromatography (HPLC), and HNS was confirmed through differential scanning calorimetry (DSC) and nuclear magnetic resonance (¹H-NMR).