In situ Raman spectroscopy of the decomposition of tertiary butyl peroxy pivalate under high pressure and high temperature

The decomposition of tertiary butyl peroxy pivalate (TBPPI), in n-hexane, under a pressure of 1900 bar and at a temperature of 100 degreesC, was studied in situ with the use of a transportable high-throughput fiber-optic Raman spectrometer. The Raman probe was conveniently coupled to an optical high-pressure cell containing the TBPPI, Time-resolved experiments with a 10 wt % solution of TBPPI in n-hexane were carried out, and information on the mechanism of decomposition and the (first-order) kinetics was obtained, It is shown that the main decomposition products of TBPPI are CO, and t-butanol, From first-order kinetic fits, of the Raman profiles of intensity vs. time of reactants and products, the rate constant for the decomposition of TBPPI and the formation of CO, is found to be 1.65 . 10 (3)s (1) (half-life time for TBPPI of approximately 420 s). t-Butanol formation occurs at a slower rate of approximately 1.22 . 10 (3)s (1) (characteristic time of 566 s).