Alternate method for synthesis of 1,3,3-trinitroazetidine (TNAZ): next generation melt castable high energy material

Abstract

The synthesis of 1,3,3-trinitroazetidine (TNAZ) from 2,2-dinitropropane-1,3-diol precursor derived from nitromethane is described. The cyclization of 1,3-dichloro-2,2-dinitropropane in presence of t-butyl amine to t-butylated azetidine ring, followed by its nitration afforded target molecule TNAZ in minimum number of synthesis steps. TNAZ was characterized by elemental analysis, Spectral Energy Dispersive Analyser-X-ray (EDAX), and Scanning Electron Microscope (SEM) techniques. Thermolysis studies on TNAZ were undertaken using Differential Scanning Calorimetry (DSC) and Thermo Gravimetric (TG) techniques. The Fourier Transform Infrared (FTIR) of decomposition products of TNAZ revealed the evolution of oxides of nitrogen and -CN containing species suggesting the cleavage of C/N-NO₂ bond accompanied with the collapse of the ring structure. The sensitivity data obtained for the TNAZ indicated its sensitive nature towards external stimuli (Impact height (h_50%) for explosion > 47 cm; Friction insensitive up to > 36 kg). The theoretically predicted performance parameters suggest that TNAZ is energetically superior in terms of velocity of detonation (VOD: 8.6 km/s) and power index (PI: 182) compared to the conventionally used melt castable high explosive 2,4,6-trinitrotoluene (TNT) (VOD-6.66 km/s and PI-125).