Evaluation of thermal hazard characteristics of four low temperature reactive azo compounds under isothermal conditions

The polymerization reaction can lower the threshold of the required energy by the initiator to improve the efficiency of the overall process reaction. Emerging polymerization initiators are also a major focus of process improvement and technological progress. Azo compounds (azos), which used in dyeing applications, are subsequently used in polymerization reactions due to their highly exothermic reaction characteristics. Although higher heat release can promote polymerization and modify the product, heat generation may also cause process hazards. These thermal hazard parameters were studied by selecting dimethyl 2,2′-azobis(2,4-dimethylvaleronitrile) (ABVN), 2,2′-azobis(2-methyl propionate) (AIBME), 2,2′-azobis(2-methylpropionamide) dihydrochloride (AIBA), and 2,2′-azobis(isobutyronitrile) (AIBN), which are common azo initiators at present. Thermal hazards are closely related to the reaction kinetics of the substance itself. The form of the reaction, the apparent activation energy and the thermodynamic parameters of the exothermic mode were also obtained. Kinetic analysis of the actual process using the experimental data of the isothermal calorimetry model is rarely used in the evaluation of related thermal hazard characteristics. The simulation results revealed the kinetic azo models and were further applied to calculate the runaway situations of azo under specific boundary conditions. •The results of laboratory-scale were used to identify thermal hazards in the plant.•The kinetics of four azos was studied by analytical model.•Kinetic simulations were used to evaluate of thermal equilibrium for four azos.•The kinetic model under the process conditions is determined.•Thermal stability (TMRad and TCL) with runaway reaction was found by analysis.