The temperature dependence of the relaxation times of the structural relaxa
tion process of polystyrene is determined by temperature-modulated differen
tial scanning calorimetry (TMDSC) and by conventional differential scanning
calorimetry (DSC) in the latter by modelling the experimental heat capacit
y curves measured in heating scans after different thermal histories. The g
ood agreement between both measuring techniques in the temperature interval
just above the glass-transition temperature is a guide for the interpretat
ion of the results of the TMDSC technique in the glass-transition region. I
n addition, the same model applied to DSC scans is used to simulate the TMD
SC experiment and the calculated response is compared with the measured sca
ns.