MODULATED DIFFERENTIAL SCANNING CALORIMETRY IN THE GLASS-TRANSITION REGION .2. THE MATHEMATICAL TREATMENT OF THE KINETICS OF THE GLASS-TRANSITION

Temperature-modulated differential scanning calorimetry (TMDSC) is bas ed on heat flow and represents a linear system for the measurement of heat capacity. As long as the measurements are carried out close to st eady state and only a negligible temperature gradient exists within th e sample, quantitative data can be gathered as a function of modulatio n frequency. Applied to the glass transition, such measurements permit the determination the kinetic parameters of the material. Based on ei ther the hole theory of liquids or irreversible thermodynamics, the ne cessary equations are derived to describe the apparent heat capacity a s a function of frequency.