Spectroscopic and thermal studies on the decomposition of l,3,5-triamino-2,4,6-trinitrobenzene (TATB)

The kinetics of the thermal decomposition of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) in condensed state has been investigated by high temperature infrared spectroscopy (IR) and thermogravimetry (TG) in conjunction with pyrolysis gas analysis, differential thermal analysis (DTA) and hot stage microscopy. The decomposition proceeds in two main stages under isothermal conditions and the initial stage involving about 24% loss in weight obeys Avrami-Erofe'ev equation (n= 1), and is governed by an activation energy (E) of 150.58 kJ·mol^–1 and log(A in s^–1) 12.06. The second stage corresponding to 24 to 90% loss in weight gave best fit for Avrami-Erofe'ev equation,n=2, withE=239.56 kJ·mol^–1 and log(A in s^–1) 19.88 by isothermal TG. The effect of additives, on the initial thermolysis of TATB has also been studied. Evolved gas analysis by IR showed that NH₃, CO₂, NO₂, HCN and H₂O are produced in the initial stage of decomposition. The decomposition in KBr matrix in the temperature range 272 to 311.5°C shows relative preferential loss in the -NH₂ to -NO₂ band intensity which indicates that the rupture of C-NH₂ bond, weakened also by the interaction of the NH₂ with the neighbouring NO₂ group, appears to be the primary step in the thermolysis of TATB.