Analysis of the thermal hazard of benzoyl peroxide in the presence of phenyl groups

Benzoyl peroxide (BPO) is a thermally sensitive organic peroxide prone to thermal runaway under incompatible conditions. This study investigates the thermal decomposition behavior of BPO and its mixtures with phenyl-containing compounds (toluene, benzene, biphenyl, p-terphenyl) using differential scanning and adiabatic calorimetry. Apparent activation energies were calculated using Starink and Friedman methods across a conversion range of 0.1–0.9. Results show that the addition of phenyl compounds lowers both the initial decomposition temperature and activation energy of BPO, with benzene having the most significant effect. Adiabatic analysis revealed two distinct decomposition stages, low- and high-temperature regions, characterized by different kinetic behaviors. The early stage showed higher activation energy and stronger autocatalytic features. Overall, the presence of phenyl-containing substances reduces the energy barrier and thermal runaway threshold of BPO systems, increasing their thermal reactivity and hazard. These findings provide a reference for safety assessment and hazard control in the storage and handling of BPO and related materials.