Investigation on kinetics and mechanism of thermal decomposition of N, N-dinitropiperazine

The thermal decomposition mechanism of N, N′-umtropiperazine (DNP) was studied by means of high pressure differential scanning calorimetry (PDSC), thermogravimetry analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy technology; Condensed-phase change of decomposition process was analyzed by means of in situ thermal decomposition cistern FTIR technology. Finally the thermal decomposition kinetics equation and the specific process of thermal decomposition and chemical reaction were obtained. The results show that DNP sample cannt decompose normally under 0.1 MPa pressure because of its volatilization; while its decomposition process becomes simple under 2 MPa, 4 MPa and 6 MPa pressure. There appears a sharp endothermic peak at 217°C due to melting of DNP sample. The change of pressure hardly affects its decomposition process, and the main endothermic peak appears at 244.2°C to 251.7°C. There exists a sharp endothermic peak at about 300°C. after the maximum en-dofhermic peak, and the sharp peak becomes obvious gradually with the increase of the pressure, which shows that DNP can decompose continuiously under high pressure. The E_s of DNP obtained by three different calculation methods is within 103 kJ·mol^-1 to 124 kJ·mol^-1. Finally the thermal decomposition mechanism functions were obtained through analysis and calculation.