A Novel Insensitive Cocrystal Explosive Composed of BTF and the Non-Energetic 2-Nitroaniline

Abstract

Benzotrifuroxan (BTF) is a powerful energetic material (EM) with high density that can be used both as a primary and a secondary explosive. However, high mechanical sensitivity limits its application prospects. To actualize its potential, cocrystallization was introduced into BTF-based EMs for insensitivity improvement in the current work. A novel cocrystal explosive composed of BTF and a non-energetic molecule (2-Nitroaniline (ONA)) was prepared with a molar ratio of 1:1. The possible mechanism of cocrystal formation was studied by the analysis and characterization of its crystal structure, and the crystal structure, thermal decomposition, and energetic properties were investigated. The results indicate that the formation of the BTF/ONA cocrystal is mainly attributed to the strong interactions of the hydrogen bonds formed between the hydrogen on the amino group in the ONA molecule and the oxygen and nitrogen atoms in BTF. The impact sensitivity of BTF/ONA is obviously reduced, with the drop height of 50% explosion probability (H50) increasing from 56.0 to 90.0 cm. The calculated detonation velocity and detonation pressure of the BTF/ONA cocrystal are 7115.26 m/s and 20.51 GPa, respectively. The decomposition peak temperature of the BTF/ONA cocrystal (191.1 °C) decreases by about 90.9 °C compared to BTF (282.0 °C). This suggests that cocrystallization could effectively reduce its impact sensitivity and produce an explosive with excellent comprehensive properties.