Thermal Stability Studies of Benzoyl Peroxide Systems
Abstract
Organic Peroxide is one of the common reactive chemical classes. Their unstable O-O bonds make them very useful, but also hazardous due to highly exothermic decomposition, which can result in runaway reactions. Benzoyl peroxide (BPO) is one of the most commonly used organic peroxides in market and the hazards have been revealed in many incidents. To prevent conditions leading to a thermal runaway, it is necessary to understand the kinetics, thermodynamic properties and critical safety parameters of the systems involving reactive chemicals.
In this research, calorimetric experiments were employed to characterize the runaway behavior of BPO in different systems. The aim was the advancement of understanding the thermal risks of BPO under various conditions in a systematic and comprehensive approach. More specifically, BPO was studied in three different systems: 1) solid phase BPO decomposition, 2) BPO decomposition in solvent, and 3) BPO compatibility study in mixtures with selected acids, bases or salts. Chemical reactivity of BPO in different systems were investigated experimentally using screening techniques and adiabatic calorimeter.
Significant differences in thermal behavior and reaction pathways were observed in different systems involving BPO. Solid BPO was tested in pseudo-adiabatic calorimeter to study the condition-dependent BPO decomposition, including the effect of sample size, confinement, and additives. The information was useful in identifying safer operation conditions to avoid exposure of BPO to heat, confined spaces or incompatible materials, and to prevent thermal explosion. BPO-solvent system was evaluated in adiabatic calorimeter. A quantitative assessment of the effects of sample volume and mass fraction on thermal runaway was conducted. The thermal hazards associated with process scaling up and process deviation were revealed. In addition, the effect of dry fire-extinguishing chemicals on BPO stability was assessed. The results showed that sodium bicarbonate and potassium bicarbonate could reduce the “onset” temperature, and reduce the pressure hazard of solid BPO decomposition, and ammonium dihydrogen phosphate had an inhibition effect on BPO decomposition. We anticipate this research to provide useful information in terms of thermal runaway prevention, protection layer design, and developing emergency responding measures in order to safely handle energetic BPO in storage, transportation, manufacturing, production processes, as well as safely tackle BPO-related fires.
Citation
Shen, Yueqi (2020). Thermal Stability Studies of Benzoyl Peroxide Systems. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /192690.