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

Abstract

Micro/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 d 50 = 3.14 μm, high sphericity of 0.944 with hollow structure and bulk density of 1.851 g/cm 3 . 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 À 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 N 2 , H 2 O, N 2 O, NH 3 , NO, NH 2 , CO 2 , 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 (H 50 ) increased from 50.1 cm to 70.8 cm, and the friction sensitivity (P) decreased from 24 % to 0 %, showing improved safety performance.