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A differential/integral method to estimate the kinetic parameters (apparent activation energy Ea and pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied to study the nonisothermal decomposition reaction kinetics of hexanitrohexaazaisowurtzitane (HNIW) by analyzing nonisothermal DSC curve data. The apparent activation energy (Ea) obtained by the integral isoconversional non-isothermal method based on Kooij formula is used to check the constancy and validity of apparent activation energy by the differential/integral method based on Kooij formula. The most probable mechanism function of thermal decomposition reaction of HNIW is determined by a logical choice method. The equations for calculating the critical temperatures of thermal explosion (Tb) and adiabatic time-to-explosion (tTIad) based on Kooij formula are used to calculate the values of Tb and tTIad to evaluate the thermal safety and heat-resistant ability of HNIW. All the original data needed for analyzing the kinetic parameters are from nonisothermal DSC curves. The results show that the kinetic model function in differential form and the values of Ea and A of decomposition reaction of HNIW are 3(1 − α)[−ln(1 − α)]2/3, 152.73 kJ mol−1 and 1011.97 s−1, respectively, and the values of self-accelerating decomposition temperature (TSADT), Tb and tTIad are 486.55 K, 493.11 K and 52.01 s, respectively.

The thermal decomposition and the nonisothermal kinetics of the thermal decomposition reaction of 2,4,6,8-tetranitro-2,4,6,8-tetraazabicyclo[3,3,1]onan-3,7-dione are studied. Calculations suggest that the N-N bond trigger bond during the pyrolysis initiation process.

To evaluate the stability, heat-resistance ability and thermal safety of MNPP(1H,4H-3-methyl-6-nitro-pyrazolo[4,3-c]pyrazole), CNPP (1H,4H-3-carboxy-6 -nitro-pyrazolo[4,3-c]pyrazole), DNPP (1H,4H-3,6-dinitro-pyrazolo [4,3-c] pyrazole), the theoretical investigation on MNPP, CNPP and DNPP was performed by the DFT-B3LYP/6-31G level using Gaussian 09W program. The theoretical density (ρ) of the compounds was obtained by quantum chemical method. The Kamlet-Jacobs formulas were employed to calculate the detonation properties including the detonation velocity (D) and pressure (P). Their thermal behaviors were investigated by Differential Scanning Calorimetry (DSC), Thermogravimetry-Derivative Thermogravimetry (TG-DTG) and in-situ cell thermolysis/Rapid-Scan Fourier Transform Infrared Spectroscopy (RSFT-IR). Results show that (1) using critical temperature of thermal explosion, free energy of activation of decomposition reaction and self-accelerating decomposition temperature as criterions, the thermal stability, heat resistance ability and thermal safety of the three compounds decrease in the order of DNPP > MNPP >CNPP, but using energy gap and total energy as criterions, the thermal stability decreases in the order of DNPP > CNPP > MNPP, therefore, DNPP is the most stable compound among the three compounds; (2) Among of the three compounds, DNPP possesses the maximum theoretical density (1.80 g• cm-3), the fastest detonation velocity (8.49 km• s-1) and the highest detonation pressure (31.96 GPa), suggesting that DNPP has good detonation properties and potential use in energetic material. [ABSTRACT FROM AUTHOR]

Estimates the critical rate of temperature increase of thermal explosion for the first order autocatalytic decomposition reaction system using non-isothermal differential scanning calorimetry. Information on increasing rate of temperature in nitrocellulose; Percentage nitrogen in the nitrocellulose when the first order autocatalytic decomposition converts into thermal explosion.