Crystallization and polymorphism of l-arabitol

The crystallization process of l-arabitol was investigated using differential scanning calorimetry (DSC) and X-ray diffraction. In order to estimate the temperature range where the rates of nucleation and growth reach their maximum, we have applied an experimental protocol consisting in a succession of quenching of the liquid at different temperatures followed by a heating ramp. It enabled us to show that the nucleation and growth domains were clearly separated and a metastable polymorph of lower melting point was obtained. The conditions for the appearance of this form have been studied in detail. The crystallization kinetic of the undercooled liquid at T = 0 °C, followed by X-ray diffraction, has permitted to show that the stable form was obtained after the transient metastable form.

► The crystallization process of l-arabitol is analyzed by DSC and X-ray diffraction.
► The nucleation and growth temperature domains are determined.
► We analyzed the thermal conditions for the appearance of a metastable polymorph.
► We highlight the role of the polymorphic transition in the crystallization process.