Thermal hazards of benzoyl peroxide and its derived process products through theoretical thermodynamics assessment and different calorimetric technologies.

Benzoyl peroxide (BPO) is one of the primary OPs used as an initiator, curing agent, or medicine. Some of the plastic processes use BPO without air for maintaining the efficiency of the entire reaction. However, there have been numerous accidents involving BPO in petrochemical plants, especially those related to fire and explosion, that are due to its unstable thermal properties and peroxy bond (OO). BPO can be identified as a typical substance with autocatalytic reaction characteristics. Therefore, the related processes and their products are critical to prevent these kinds of chemical contingencies. This research was based on two types of instruments (nonisothermal and isothermal calorimetry), and theoretical methods to further determine the thermal hazard level. From the experimental results for BPO and BPO mixed with its by-products, the heat of decomposition was much higher (from 800 to 1235 J/g), the time to maximum rate under isothermal conditions was much shorter (from 99.1 to 17.4 h at 75.0 °C), and the apparent activation energy was much lower (from 118 to 91 kJ/mol) after BPO was mixed with its by-products. Therefore, the hazard level of BPO mixed with its by-products from the reaction process was much higher than that of pure BPO.