Calorimetric study of maltitol: correlation between fragility and thermodynamic properties

Abstract

The heat capacity of maltitol was measured with an adiabatic calorimeter. The crystalline form was measured from 100 to 425 K ( T m=420 K), the glass form from 249 K to T g (around 311 K) and the liquid form from T g to 400 K. The heat of melting is 55.068 kJ mol −1. The calorimetric glass transition occurs at about T g=311 K with a sudden jump of the heat capacity Δ C p( T g) of about 243.6 J mol −1 K −1. The excess entropy between the under-cooled liquid and the crystal was calculated from the heat capacity data and was used to estimate the Kauzmann temperature T K, which was found to be 50 K below T g. Δ C p( T g) and T K values for maltitol were compared with those of other compounds such as sugars, polyols and hydrogen-bonded liquids. It was found that the glass former maltitol is a ‘fragile’ liquid from the thermodynamic point of view.