Spectroscopic and thermal studies on 2,4,6-trinitro toluene (TNT)

The kinetics and mechanism of the initial stage of thermal decomposition of 2,4,6-trinitro toluene (TNT), a widely used high explosive, have been stud ied, together with its morphology and evolved gaseous products using thermo gravimetry (TG), differential thermal analysis (DTA), infrared spectroscopy (IR) and hot-stage microscopy. The kinetics of the thermolysis has been fo llowed by IR after suppressing volatilisation by matrixing and by isotherma l TG without suppressing volatilisation to simulate actual user conditions. The best linearity was obtained for Avrami-Erofeev equation for n=1 in iso thermal IR and also in isothermal TG. The activation energy was found to be 135 kJ mol(-1), with logA (in s(-1)) 12.5 by IR. The effect of additives o n the initial thermolysis of TNT has also been studied. Evolved gas analysi s by IR showed that CO2, NO2, NO and H2O are more dominant than N2O, HCN an d CO. The decomposition involves the initial rupture of the C-NO2 bond, wea kened by hydrogen bonding with the labile hydrogen atom of the adjacent CH3 group, followed by the abstraction of the hydrogen atom of the methyl grou p by NO2, generated in the initial step.