Dynamic differential scanning calorimetry is a relatively new thermal analysis procedure that modulates the temperature ramp of the ordinary differential scanning calorimeter. This modulation makes it possible to separate out reversible (such as melting) vs. irreversible (such as physical aging) transitions. The accuracy of this procedure was investigated by analyzing physical aging in poly(ethylene terephthalate).

The accuracy of the DDSC is very dependent upon the parameters chosen. Improper parameters could, for example, result in insufficient time to establish equilibrium in the sample. The parameters must also be modified as the aging times are extended for the same aging temperature.

The data collected was consistent with what was expected from the literature. Physical aging was found to be linear with log time except at the higher aging times. The DDSC has shown potential for quantifying enthalpic relaxation effects resulting from the phenomenon of physical aging.