Preparation and characterization of superfine spherical TKX‐50 with a hollow structure by spray drying

Abstract

AbstractMicro/nano energetic materials with regular morphologies exhibit high energy release efficiency, superior charge performance, and low mechanical sensitivity. Exploring dihydroxylammonium 5,5′‐bistetrazole‐1,1′‐diolate (TKX‐50) with spherical microstructures and excellent comprehensive properties is of great significance for potential applications. In this work, a kind of superfine spherical TKX‐50 was fabricated by spray drying method. The as‐prepared TKX‐50 had a narrow particle size distribution with d50=3.14 μm, high sphericity of 0.944 with hollow structure and bulk density of 1.851 g/cm3. And its formation mechanism was proposed. The results of XRD and FT‐IR demonstrated that spray drying would not change the crystal structure of TKX‐50. TG‐DSC results showed that the initial decomposition and the peak temperature of superfine spherical TKX‐50 was about 10 °C lower than raw TKX‐50, and the apparent activation energy was 4.584 kJ ⋅ mol−1 lower than raw TKX‐50, due to the dramatic change in morphology. TG‐DSC‐FTIR‐MS provided a new understanding of decomposition process of TKX‐50, and the results illustrated that the main gas products were N2, H2O, N2O, NH3, NO, NH2, CO2, and HCN. Superfine spherical TKX‐50 underwent similar decomposition path as raw TKX‐50 but stood out in its larger occupation of the first decomposition which meant a more complete decomposition and its faster rate of the whole decomposition process. More importantly, the impact sensitivity (H50) increased from 50.1 cm to 70.8 cm, and the friction sensitivity (P) decreased from 24 % to 0 %, showing improved safety performance.