Liquidus and glass transition temperatures of the ammonium nitrate-dimethylsulfoxide-water system

The liquidus temperature was measured in the ammonium nitrate-dimethylsulfoxide-water system over in the concentration range 0–60 mole% ammonium nitrate. The probable formation of the NH₄NO₃·nDMSO solvate with n=1.3–1.5 and the mixed solvate NH₄NO₃·DMSO·H₂O at 30 mole% ammonium nitrate and a DMSO:H₂O ratio of 4∶1 are indicated. The glass transition temperatures T _g were measured over a salt concentration range of 0–50 mol% ammonium nitrate and at various compositions of the mixed solvent (y _DMSO =0.1–0.9 mole fraction). At a constant mixed solvent composition, the dependence of the glass transition temperature on the salt concentration can be approximated by a linear relationship, as can its dependence on the DMSO content in the solution at constant salt concentration. The glass-forming composition regions were found and the limits of this region are discussed.