The Solubility of ϵ-CL-20 in Selected Materials

The solubility of the epsilon polymorph of CL-20 was determined in thirteen liquids over the temperature range of ambient to 74°C using high performance liquid chromatography. The experiments included ϵ-CL-20 produced by two different synthesis routes; one lot contained a higher level of polymorphic impurity, the other lot contained a higher level of non-CL-20 impurity.In general, the ϵ-CL-20 was found to be highly soluble in the solvents with carbonyl groups, and relatively insoluble in hydrocarbons and materials containing ether linkages. The amount of phase conversion to γ-CL-20 which occured during the solubility testing was measured using FTIR, and ranged from essentially zero to ∼ 10% conversion. It appears that the presence of β-CL-20 in the virgin ϵ-CL-20 lots will affect the amount of gamma-phase present in the final residue.