Abstract:

To address the issue of significant errors in measuring the energy content of high-energy chemicals using conventional calorimetry, trace amounts of samples were loaded into glass capillary crucibles, and their thermal decomposition characteristics were tested using differential scanning calorimetry (DSC). The energy contents of four high-energy chemicals—trinitrotoluene (2,4,6-TNT and 2,3,6-TNT), nitromethane, and tetryl—were analyzed to obtain their thermal decomposition profiles and endothermic/exothermic data. Furthermore, the decomposition reaction mechanisms of these complex polynitro compounds were thoroughly investigated, and their explosive property ranges were evaluated using the Yoshida correlation. The results indicate that, compared to the commonly used high-pressure gold-plated crucibles, filling samples in glass capillary crucibles offers greater advantages in reliability and cost-effectiveness. The energy contents of 2,4,6-TNT and nitromethane measured in glass capillary crucibles were -4 545.9 and -5 436.5 J/g, respectively, while those measured in high-pressure gold-plated crucibles were -2 907.6 and -2 997.5 J/g; in comparison, the energy contents measured in the glass capillary crucibles are much closer to the theoretical values (-4 184 and -5 246 J/g). Meanwhile, the measurement errors of the glass capillary crucible method are maintained within 10%, demonstrating good reproducibility and high measurement accuracy.

Key words: glass capillary crucible, differential scanning calorimetry(DSC), high-energy chemicals, energy content, high-pressure gold-plated crucible