Thermal hazard evaluation of tert-butylperoxy-2-ethylhexanoate mixed with H2O and NaOH solution

Abstract

Tert-butylperoxy-2-ethylhexanoate (TBEC)—an easily decomposable organic peroxide—is widely used as a polymerization initiator in industrial production. Sodium hydroxide solution and water are common impurities in the polymerization process. In this study, exothermic onset temperature (T0) and heat of decomposition (ΔH) of TBEC with impurities were obtained through differential scanning calorimetry. In addition, maximum pressure (Pmax), maximum temperature (Tmax), and adiabatic temperature rise (ΔTad) were obtained through accelerated rate calorimetry (ARC). Apparent activation energy (Ea) scores for pure TBEC and TBEC mixed with water (TBEC/H2O) and sodium hydroxide (TBEC/NaOH) were calculated. Subsequently, based on experimental data obtained through ARC, the self-accelerating decomposition temperature and temperature at the time to maximum rate under adiabatic conditions were calculated for 24 h (TD24) and 8 h (TD8). The experimental results indicated that H2O negligibly affected T0 but decreased ΔH, Pmax, Tmax, and ΔTad. Moreover, addition of H2O increased the TD24 and TD8 of TBEC. Thus, the thermal hazard of TBEC was reduced by addition of H2O. Addition of NaOH solution increased the complexity of the reaction because the initial decomposition temperature and activation energy were negatively correlated to the content of NaOH in the solution.