An Efficient Method of Preparation and Comprehensive Properties for Energetic Salts Based on Nitrofurazan-Functionalized Hydroxytetrazoles

Based on the advantages of the furazan and tetrazole ring, the nitro and N-oxide groups were introduced into furazan-tetrazole backbone to four kinds of novel nitrofurazan-functionalized hydroxytetrazole energetic salts. Various method have been employed to confirm their structures, such as multinuclear NMR, FTIR spectroscopy and elemental analysis. Salt guanidinium 5-(4-nitro-furazan-3-yl)-tetrazole-1-olate (5) and salt potassium 5-(4-hydroxyamino-furazan-3-yl)-tetrazole-1-olate (6) has been further elucidated by single-crystal X-ray diffraction. The non-isothermal decomposition kinetics and thermodynamics for different salts were investigated by using TG-DSC with different heating rate. The physico-chemical properties and detonation performance were also studied and calculated by EXPLO5 program, in which salt hydroxylammonium 5-(4-nitro-furazan-3-yl)-tetrazole-1-olate (3) have a relatively high density of 1.839 g⋅cm⁻³ at 296 K and good detonation properties (v_D = 9228 m⋅s^-1, P = 38.0 GPa), which is superior to that of RDX. The sensitivities towards impact and friction were also determined by BAM method (BAM Fallhammer Test for IS; BAM Friction Test for FS), in which the salt 5 showed very insensitive property (IS>60 J, FS>360 N) and can be comparable to that of TATB. Furthermore, the specific impulse of salt 3 (281 s) was even better than that of ammonium perchlorate (AP) (157 s) as neat compounds.