Thermomechanical analysis of frozen aqueous systems

Thermomechanical Analysis (TMA), using the parallel-plate-rheometer mode of the DuPont 943 TMA, was used to evaluate the softening properties of frozen aqueous carbohydrate model systems. A sample (of fixed dimension) of frozen solution was placed between the parallel plates and cooled to -80 degrees C. The sample was then heated at a linear heating rate of 2 degrees C/min to +15 degrees C. The dimension change was plotted as a function of temperature or time, and an estimate was made of the glass transition point and of the thermal softening behavior of the system. Good agreement was found with previously published glass transition data for similar frozen carbohydrate model systems measured by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA).