Direct measurement of reaction rate for decomposition of diisopropyl methylphosphonate at high temperature using shock tube and laser absorption

Abstract

Diisopropyl methylphosphonate (DIMP) is an organophosphorus compound used as a simulant for the chemical weapon Sarin. One of the means of destruction of Sarin is incineration at high temperature, which requires a clear understanding of the high‐temperature reaction kinetics of Sarin. In this work, we study the reaction rate for thermal decomposition of DIMP in the temperature range of 762–1059 K at a pressure near 1 atm. Test conditions are carefully chosen to minimize interferences from other reactions and intermediates formed during the decomposition process. The experimental rates obtained have been fitted for the Arrhenius rate expression to get the rate parameters of the reaction r1, DIMP (C7H17O3P) = IMP (C4H11O3P) + propene (C3H6) as r1(s−1)badbreak=1015.058±0.5e−false(47497±1935(calmol)false)/RT\begin{equation*} {r_1}\;( {{s^{ - 1}}} ) = {10^{15.058 \pm 0.5}}\;{e^{ - ( {47497 \pm 1935( {\frac{{cal}}{{mol}}} )} )/RT}} \end{equation*}The rate obtained in this work extended the temperature range of previous measurements (up to 800 K) and can be used in reaction kinetic models for combustion of DIMP.