KINETICS OF THE AQUEOUS ALKALINE HOMOGENOUS HYDROLYSIS OF HIGH EXPLOSIVE 1,3,5,7-TETRAAZA-1,3,5,7-TETRANITROCYCLOOCTANE (HMX)

In order to get basic data for the design of a novel treatment scheme for high explosives we investigated the kinetics for the aqueous alkal ine hydrolysis of 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane (HMX) and the temperature dependence of the rate constants. We used an HPLC procedure for the analysis of HMX. All experimental data could be fit accurately to a pseudo first-order rate equation acid subsequent calc ulation of second-order rate constants was also precise. Temperature d ependence could be modeled with the Arrhenius equation. An increase of 10 degrees C led to an average increase in the second-order rate cons tants by the 3.16 fold. The activation energy of the second-order reac tion was determined to be 111.9 +/- 0.76 kJ.mol(-1). We found the alka line hydrolysis to be rapid (less than 2.5% of the initial HMX-concent ration left after 100 minutes) at base concentrations of 23 mmol OH-/L and elevated temperatures between 60 and 80 degrees C.