Optimization of the Synthesis Parameters and Analysis of the Impact Sensitivity for Tetrazene Explosive

Tetrazene [1-(5-tetrazolyl)-4-guanyltetrazene hydrate] is widely used in ordnance systems as a sensitizer of primer compositions, for use in both percussion and stab applications. It can be synthesized by reacting aminoguanidinium bicarbonate (AGB) with sodium nitrite (NaNO2) in the presence of acetic acid. However, little is known about its optimal synthesis parameters in the manufacturing process. In this study, Taguchi's experimental design method was used to further improve the yield of tetrazene. Under the condition that the molar ratio of AGB to NaNO2 was fixed at 1.0:1.2, a L9(33) orthogonal array with three control factors and three levels for each control factor was used to design nine experimental conditions. The experimental data were transformed into a signal-to-noise (S/N) ratio to analyze and evaluate the experimental conditions of the optimal parameter combination for the maximum yield of tetrazene. Verification of the results indicated that the optimal synthesis parameters were as follows: pH value of AGB solution was 5.0, reaction temperature was 35 °C and reaction time was 6 h; the maximum yield of tetrazene could reach 83.7%. Furthermore, the synthesized tetrazene was identified and characterized by elemental analysis (EA), nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), optical microscopy (OM),particle size distribution analysis (PSDA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), and its impact sensitivity was determined using a BAM Fallhammer apparatus and the Bruceton analysis method.