Thermal safety and overall kinetics for methyl methacrylate solution polymerization via on-line process analytical technology

•Polymerization runaway characteristic is greatly affected by monomer concentration.•Thermal hazard is mainly concentrated in the initiator dosing phase.•Kinetic parameters are determined and agree well with calorimetric data.•Reaction exhibits endergonic, endothermic, and nonspontaneous characteristics.•Reaction product is thermally stable, making the reaction somewhat controllable. Polymethyl methacrylate (PMMA) is widely used, but its polymerization process is highly hazardous and the relevant thermal hazards have not been adequately investigated. Herein, the thermal safety and kinetic mechanisms of methyl methacrylate (MMA) polymerization are explored. The effect of monomer concentration on the exothermic characteristics is first investigated using a reaction calorimeter. The results indicate that the exothermic behavior of this reaction is significantly influenced by the monomer concentration. Meanwhile, a quantitative relationship between the specific enthalpy and monomer concentration is determined. Moreover, overall rate expression is developed by a rapid quantitative method to further elucidate the quantitative dependence of reaction rate on the process conditions. Subsequently, adiabatic experiment is performed to reveal the thermal controllability of this reaction. Finally, risk level is ascertained to propose constructive countermeasures. This work provides guidance for the safe operation of MMA polymerization, and the methodology also furnishes universal solutions for analogous reactions.