Metastability release of the form alpha of trehalose by isothermal solid state vitrification
Résumé
Kinetic investigations of the polymorphic form α of anhydrous trehalose have been performed below its apparent melting temperature (Tm) by differential scanning calorimetry (DSC) and X-ray diffraction. The results reveal a spontaneous isothermal vitrification process which indicates that the phase α is in a very unusual superheating situation. This behavior has been attributed to the fact that the effective melting temperature ( ) of the phase α is likely to be located far below the glass transition temperature (Tg) of this compound. The high viscosity of the liquid trehalose between and Tg is thus invoked to explain the long lifetime of the phase α in this temperature range.