The mechanism of thermal decomposition of the lead(II) salt of 2,4-dinitroimidazole (PDNI) was studied by means of TG, simultaneous TG-DSC-FTIR-MS and thermolysis in situ rapid-scan FTIR. The results indicate that the coordinated H2O is firstly escaped from PDNI molecules at the temperature of approximately 102 ℃; NO2 is produced as C—NO2 bond is broken, the imidazole ring is ruptured with simultaneous strong exothermic process at the temperature of approximately 289 ℃, the gaseous and condensed products of PDNI consist of CO2, N2O, NO2 and complex mixtures of lead(II) salt of poly unsaturated hydrocarbon from imidazole residual; CO2, N2O and Pb[NCO]2 are produced as PDNI continuously slowly decomposes in the temperature range of 300 to 400 ℃; CO and Pb[CN]2 are finally produced as temperature increases to higher than 410 ℃.

Key words: lead(II) salt of 2,4-dinitroimidazole, thermal decomposition, TG, DSC, MS, FTIR