Sublimation enthalpy of homemade peroxide explosives using a theoretically supported non-linear equation

Abstract

A non-linear thermal fitting, which was theoretically supported, was used to determine sublimation enthalpies of cyclic organic peroxide explosives using thermogravimetry analysis and FT-IR grazing-angle techniques. TG and FT-IR grazing-angle experiments consisted in the determination of mass loss rate at several isothermal points. The sublimation and decomposition enthalpy values were comparable with previously reported by another method. Amino-peroxide explosives showed a profile different from acetone-peroxide explosives. In this field of study, it is typical to calculate the vapor pressure from rate constant values using the Langmuir equation and then fit the obtained values according to Clausius–Clapeyron equation to find standard enthalpy values. The proposed method is direct because it resulted from fitting of the sublimation constant rate of (K sub) with the temperature without assuming approximated values for certain constants of the Langmuir equation. The R-square values of the fittings obtained were all above 0.999+, which indicates a high level of acceptance. This thermal analysis was done in a wide range of temperature and a temperature step of 1 °C/point generating remarkable tendencies with many points.