Optimization of Synthesis Parameters and Characterization of Green Primary Explosive Copper(I) 5‐Nitrotetrazolate (DBX‐1)

Abstract

AbstractSince the early 20th century, lead azide (LA) has been commonly used as a primary explosive. However, lead pollution in the air and soil has attracted more and more attention, particularly in military training grounds and shooting ranges. Copper(I) 5‐nitrotetrazolate (DBX‐1) is considered as one of the most promising alternatives to LA. DBX‐1 is typically prepared from sodium 5‐nitrotetrazolate dihydrate [NaNT(H2O)2] and copper(I) chloride (CuCl). But little is known about its optimal synthesis parameters. In addition, NaNT(H2O)2 is not commercially available. In this study, NaNT(H2O)2 was prepared by ourselves. Taguchi's experimental design method was used to determine the optimal experimental conditions for obtaining the maximum yield of DBX‐1. The synthesized NaNT(H2O)2 and DBX‐1 were identified by means of SEM, NMR, FTIR, EA, UV‐Vis and STA TG‐DSC, and the sensitivity of DBX‐1 was determined using BAM fallhammer, BAM friction tester and electrostatic spark sensitivity tester. The experimental results indicated that the optimal synthesis parameters of DBX‐1 were as follows: the reaction temperature was 100 °C, the reaction time was 30 min, the concentration of NaNT(H2O)2 was 0.075 wt.% and the molar ratio of NaNT(H2O)2 to CuCl was 1.15, and then the maximum yield after purification could reach 72.2 %. The decomposition activation energies of DBX‐1 calculated by Kissinger and Ozawa methods were 178.6 and 179.0 kJ/mol, respectively. In addition, the impact sensitivity, friction sensitivity and electrostatic spark sensitivity of DBX‐1 were 51 mJ, 0.4 N and 7.3 mJ, respectively, which were almost the same as those for LA.