Dicumyl peroxide (DCPO) is usually employed as an initiator for polymerization, a source of free radicals, a hardener, and
a linking agent. In Asia, due to its unstable reactive nature, DCPO has caused many thermal explosions and runaway reaction
incidents in the manufacturing process. This study was conducted to elucidate its essentially thermal hazard characteristics.
In order to analyze the runaway behavior of DCPO in a batch reactor, thermokinetic parameters, such as heat of decomposition
(ΔHd) and exothermic onset temperature (T0), were measured via differential scanning calorimetry (DSC). Thermal runaway phenomena were then thoroughly investigated
by DSC. The thermokinetics of DCPO mixed with acids or bases were determined by DSC, and the experimental data were compared
with kinetics-based curve fitting of thermal safety software (TSS). Solid thermal explosion (STE) and liquid thermal explosion
(LTE) simulations of TSS were applied to determine the fundamental thermal explosion behavior in large tanks or drums. Results
from curve fitting indicated that all of the acids or bases could induce exothermic reactions at even an earlier stage of
the experiments. In order to diminish the extent of hazard, hazard information must be provided to the manufacturing process.
Thermal hazard of DCPO mixed with nitric acid (HNO3) was more dangerous than with other acids including sulfuric acid (H2SO4), phosphoric acid (H3PO4), and hydrochloric acid (HCl). By DSC, T0, heat of decomposition (ΔHd), and activation energy (Ea) of DCPO mixed with HNO3 were calculated to be 70 °C, 911 J g−1, and 33 kJ mol−1, respectively.