Thermal decomposition and evaluation thermokinetic parameters for explosive type

In Taiwan, due to intensive religious ceremonial activities, the flying and pyrotechnic fireworks of firecrackers are commonly used. In the course of the activities, the use of water as a cooling measure has been pointed out in the past literature that it may cause pyrotechnic materials to deteriorate and reduce their thermal stability. To determine the possible influence of water addition on pyrotechnic deterioration, this study estimates the degree of thermal hazard of pyrotechnic based on the analysis of heat release, reaction kinetics, and the heat exchange model of pyrotechnic deterioration. The explosion sound (ES) firecracker was used to analyze the thermal hazard and mixed water (ES + W) to simulate the dampness condition using differential scanning calorimetry. Thermodynamic equations simulating thermal hazard safety parameters, combined with thermokinetic and thermal runaway data results, were used to discuss the safety and potential thermal hazard characteristics of ES, as the safety of fireworks in storage, transportation, process conditions, and operation assessment to curtail the probability of accidents. The results showed that if the initial exothermic temperature of ES + W is higher than ES, a thermal decomposition reaction will occur at a lower temperature, and the exothermic heat rises and the apparent activation energy decreases, indicating that the ES will increase its instability after being damp. The presence of water degenerated the ES and resulted in a violent reaction during the release process to explode the ES, which increased the chance of accidents among the onlookers.

Automated summary

This study analyzed the impact of water on pyrotechnic deterioration and discussed the thermal hazard characteristics of pyrotechnics under damp conditions caused by water addition. The results showed that the presence of water made the pyrotechnics more unstable and increased the likelihood of accidents.