Solid–Liquid Phase Equilibrium and Phase Behaviors for Binary Mixtures Composed of Tripalmitoylglycerol (PPP), 1,3-Dipalmitoyl-2-oleoyl-glycerol (POP), and 1,2-Dioleoyl-3-palmitoyl-glycerol (POO)

The crystallization and melting behaviors of binary tripalmitoylglycerol (PPP)/1,2-dioleoyl-3-palmitoyl glycerol (POO), tripalmitoylglycerol (PPP)/1,3-dipalmitoyl-2-oleoyl glycerol (POP), and 1,3-dipalmitoyl-2-oleoyl glycerol (POP)/1,2-dioleoyl-3-palmitoyl glycerol (POO) were investigated using differential scanning calorimetry (DSC). On the basis of melting phase equilibrium data, solid–liquid phase diagrams of binary systems (PPP/POO, PPP/POP, and POP/POO) were constructed. With respect to PPP/POO and PPP/POP, eutectic and solid solution phase equilibrium were confirmed when PPP content (XPPP) in the mixtures was lower and higher than 90% and 80% (w/w), respectively. For POP/POO, the solid solution and eutectic phase equilibrium were confirmed when the POP content (XPOP) in the mixtures was lower and higher than 80% (w/w), respectively. Interestingly, polymorphic transition behaviors of PPP, POP, and POO at melting stages were also revealed. Finally, melting Gibbs free energy changes based on enthalpy changes for different binary mixtures were predicted by thermodynamics models.