Vapour pressure and enthalpy of sublimation of 1,3,5,7-tetranitro-1,3,5,7-tetra-azacyclo-octane (HMX)

Abstract

The vapour pressure of 1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetra-azacyclo-octane (HMX) has been measured in the temperature range 188 to 213°C by the Knudsen effusion method, and the enthalpy of sublimation over this range calculated to be 38.7 kcal mol^–1. Similar measurements on anthracene have been made which confirm literature values.

A marked dependence of the vapour pressure, but not of its temperature variation, on the size of the effusion orifice has been observed.