Thermal hazard assessment and free radical inhibition of decomposition of tert-butyl perbenzoate

Abstract

Tert-butyl perbenzoate (TBPB) is a common initiator widely used in polymerization processes, but the peroxide bond in its molecular structure is highly susceptible to breakage, leading to decomposition or even explosion. To explore the thermal behavior of TBPB and to inhibit the thermal hazard of free radicals generated during the reaction process, well-established calorimetric techniques were applied to measure the thermal stability of TBPB. The apparent activation energy of the TBPB decomposition reaction was also calculated using the Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), and Starink kinetic method. The thermal decomposition products of TBPB were determined by Fourier transform infrared spectroscopy (FTIR) experiment, and the qualitative analysis of free radicals generated during the reaction process was conducted by electron paramagnetic resonance spectroscopy (EPR) combined with free radical trapping technology. 2,2,6,6-tetramethylpiperidinooxy (TEMPO), a free radical trapping agent and inhibitor, was selected in this study as the thermal runaway inhibitor of the TBPB thermal decomposition reaction. Its inhibition effects on the corresponding free radicals and the thermal runaway of the TBPB decomposition reaction were verified. It is found that TEMPO can effectively reduce the potential thermal dangers and accident risks of TBPB, which provides a powerful reference for the prevention and management of thermal disasters during the production, storage, and transportation of TBPB.

Keywords

• thermal stability
• apparent activation energy
• thermal decomposition product
• free radical
• thermal runaway inhibitor