The influence of substituents position on products of dinitrotoluene isomers initial thermal decomposition

Abstract

Thermal decomposition of dinitrotoluene (DNT) isomers and formed products were studied. Initial stage of thermal decomposition was the field of interests because decomposition of even a few percent of a substance may cause hazard. The generation of impurities at the initial stage of decomposition was examined on the basis of the decrease of the original substance melting enthalpy and the increase of impurities fraction determined with cryometric method. MALDI TOF was used as the independent method of formed compounds molar masses determination. Samples of DNT isomers at raised temperature (up till 480 K) undergo aggregation leading to macromolecular substances. Regardless the substituents position, the initial phase of decomposition leads to same intermediate products. Mass spectra of DNT isomers thermally conditioned contain strong signals m/z, among others, 688, 1063, 1137, 1211. Thermogravimetric analysis revealed that observed difficulties with studying the decomposition initial stage are related to high vapor pressure below decomposition temperature, what especially concerns 2,6-DNT isomer.