Binary system pentaerythritol/pentaglycerin

The complete phase diagram of the plastic crystals Pentaerythritol (PE) and Pentaglycerin (PG) has been established by means of thermal analysis and X-ray diffraction. The phase diagram is characterized by a wide crystal-plastic equilibrium and a very narrow plastic-liquid equilibrium. The crystallographic characterization allows us to conclude the total miscibility in both solid phases. Moreover, the different evolutions of the crystalline parameters of the tetragonal lattice with the concentration at 293 K are interpreted by the anisotropy between the bonds in the (001) layers (strong intermolecular hydroxyl hydrogen bond) and the bonds of the interlayers (Van der Waals forces).