Characterization on thermal decompositions of tert-butyl hydroperoxide (TBHP) by confinement test

Abstract

Thermal decomposition of 20 mass% aqueous tert-butyl hydroperoxide (TBHP) is performed by confined apparatus as a model reaction. Inductive effects are verified by of hydroxyl and tert-butoxy radicals produced by the thermolysis of H2O2 and di-tert-butyl peroxide (DTBP), respectively. Solvent effects are performed by 20 mass% TBHP in acetone, n-butyl alcohol, decane, nonane, Nujol, toluene and H2O. Thermodynamic and kinetic features, such as exothermic onset temperature, adiabatic temperature rise, maximum self-heat rate, maximum pressure and maximum temperature, are thus measured and utilized to characterize these mentioned influences. Hydroxyl radical is firstly discovered to possess the highest inductive effect on decomposition of TBHP. Exothermic onset temperature of 20 mass% aqueous TBHP is lowered from 146.0 ± 1.0 to 138.0 ± 2.0, 133.0 ± 0.0, 97 ± 8.8 and 89 °C by adding 10 mass% DTBP, 20 mass% DTBP, 10 mass% H2O2 and 20 mass% H2O2 relative to the mass of TBHP, respectively. The ranking of solvent effects on the thermal stability of solvated TBHP identified by exothermic onset temperature is arranged from high to low in the following: TBHP in toluene (178.5 ± 1.5 °C) > TBHP in decane (151.0 ± 2.0 °C) > TBHP in H2O (146.0 ± 1.0 °C) > TBHP in nonane (143.5 ± 2.5 °C) > TBHP in Nujol (138.5 ± 0.5 °C) > TBHP in acetone (128.0 ± 2.0 °C) > TBHP in n-BuOH (122.5 ± 3.5 °C).