Thermodynamic description and unidirectional solidification of eutectic organic alloys: III. Binary systems neopentylglycol-(d)camphor and amino-methyl-propanediol-(d)camphor Original Research Article

The temperature and enthalpy of transformation of organic alloys from the binary systems neopentylglycol-(d)camphor (NPG-DC) and 2-amino-2-methyl-1,3-propanediol-(d)camphor (AMPD-DC) were measured by means of differential scanning calorimetry (DSC). The phase diagrams of these binary systems were assessed via the CALPHAD approach using Thermo-Calc by simultaneously optimizing the thermodynamic and phase equilibrium data measured in the present work. Proper agreements between the experimental and calculated data for the phase diagrams as well as for the thermochemical properties were achieved. Experiments and calculations show that both the NPG-DC and the AMPD-DC system exhibit a nonvariant eutectic reaction with the eutectic point at 36.2 mol% DC and 326.0 K and at 9.3 mol% DC and 362.0 K, respectively. In each system the temperature of the eutectic reaction is higher than the temperature of the transformation from the ordered crystals to the orientationally disordered (plastic) crystals.