Solid thermal explosion of autocatalytic material based on nonisothermal experiments: Multistage evaluations for 2,2′‐azobis(2‐methylpropionitrile) and 1,1′‐azobis(cyclohexanecarbonitrile)

Abstract

AbstractTo achieve the thermal stability characteristics of azo compounds, a method for characterizing the kinetics of the reaction and decomposition for azo compounds based on nonisothermal calorimetric data was explored. Differential scanning calorimetry (DSC) was employed to analyze the thermal decomposition of two azo compounds, 2,2′‐azobis(2‐methylpropionitrile) and 1,1′‐azobis(cyclohexanecarbonitrile). DSC experiments were performed to acquire the exothermic peak temperature (Tp), exothermic final temperature (Tf), and heat of decomposition (△Hd). Corresponding thermokinetics were calculated using Flynn‐Wall‐Ozawa method. Moreover, data determined through DSC experiments were utilized to predict the self‐accelerating decomposition temperature, control temperature, and emergency temperature. A nonisothermal experiment was performed to investigate the runaway characteristics of azo compounds, the melting behavior that occurred in the decomposition process interfered with thermal analysis. Through dividing the reaction into several stages, multistage evaluations were carried out in the process of our study. During the thermal explosion simulation, the actual packing parameter of 25.0 kg was applied to ensure that the simulation results were more practical. Thermal safety parameters acquired from the simulation results can provide information on loss prevention and facilitated the establishment of an emergency relief system.Highlights The decomposition process was divided into several stages and considered melting behavior. A green method contributes to intrinsic safety design. Solid thermal explosion was simulated.