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 (P_max), maximum temperature (T_max), and adiabatic temperature rise (ΔT_ad) were obtained through accelerated rate calorimetry (ARC). Apparent activation energy (E_a) 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 (T_D24) and 8 h (T_D8). The experimental results indicated that H₂O negligibly affected T₀ but decreased ΔH, P_max, T_max, and ΔT_ad. Moreover, addition of H₂O increased the T_D24 and T_D8 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.

Keywords:

• Tert-butylperoxy-2-ethylhexanoate
• Differential scanning calorimetry
• Accelerated adiabatic calorimetry
• Thermal hazard
• Thermal kinetic parameter
• NaOH
• H₂O

Acknowledgements

The authors are grateful for the financial support received from the National Key R&D program, “Study on Safety Control Technology of Storage and Transportation Network of Hazardous Chemicals in Chemical Parks by Multi Species Coupling” (No. 2016YFC0801500), the National Natural Science Foundation of China (21436006, 51834007, 51874181, 51804167), the Jiangsu Natural Science Foundation (BK20150953), the Major Projects of the Natural Science Research for Colleges in Jiangsu Province (17KJA620002), and the Priority Academic Program Development of Jiangsu Higher Education Institutions. This manuscript was edited by Wallace Academic Editing.