Research on thermal decomposition of trinitrophloroglucinol salts by DSC, TG and DVST

The thermal decomposition of the four nitrogen-rich salts of ammonia (NH4), aminoguanidine (AG), carbohydrazide (CHZ) and 5-aminotetrazo (ATZ) based on trinitrophloroglucinol (H(3)TNPG) was investigated using the differential scanning calorimetry (DSC), thermogravity (TG), and dynamic vacuum stability test (DVST). DSC and TG methods research the complete decomposition, while DVST method researches the very early reaction stage. The peak temperatures of DSC curves are consistent with the temperatures of maximum mass loss rates of TG curves. The apparent activation energies of these H(3)TNPG-based salts obtained by DSC and DVST have the same regularity, i.e., (ATZ)(H(2)TNPG)center dot 2H(2)O < (CHZ)(HTNPG)center dot 0.5H(2)O < NH4(H(2)TNPG) < (AG)(H(2)TNPG). The thermal stability order is (ATZ)(H(2)TNPG)center dot 2H(2)O < (CHZ)(HTNPG)center dot 0.5H(2)O < (AG)(H(2)TNPG) < NH4(H(2)TNPG), which was evaluated by DVST according to the evolved gas amount of thermal decomposition. DVST can monitor the real-time temperature and pressure changes caused by thermal decomposition, dehydration, phase transition and secondary reaction, and also evaluate the thermal stability and kinetics.