Thermal Hazard Assessment of the Synthesis of 1,1′-Azobis-1,2,3-triazole

Abstract

Azo energetic compounds have attracted much attention due to their high heat of formation and high oxygen balance. However, due to a lack of safety research on this manufacturing process, industrial production cannot be carried out. 1,1′-Azobis-1,2,3-triazole was chosen as an example to identify hazardous scenarios in the synthesis of azo-energetic materials. First, the properties of the 1,1′-azobis-1,2,3-triazole synthesis experiment were studied using a reaction calorimeter (RC1). Afterward, the thermal stability of the composite materials used in the synthesis process was evaluated using accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). DSC results showed that the heat release of the mixture was significantly reduced in all three steps. ARC experiments showed that the T_D24 values of the three substances are in the range of 100.00–300.00 °C. RC1 experiments showed that the adiabatic temperature rises (ΔT_ad) in the whole process are 91.26 54.19, 51.49, and 4.10 K, respectively. These findings indicate that the exothermic reaction involved in the synthesis of 1,1′-azobis-1,2,3-triazole is initiated during the dosing phase and is affected by the dosing rate. The overall 1,1′-azobis-1,2,3-triazole synthesis process is a criticality class 1 of a chemical reaction. This holistic approach furnishes valuable data and insights for improving the engineering safety protocols of 1,1′-azobis-1,2,3-triazole, aimed at mitigating risks in industrial operations.