Three phase model in drawn thermoplastic polyesters: comparison of differential scanning calorimetry and thermally stimulated depolarisation current experiments

Differential scanning calorimetry and thermally stimulated depolarisation current measurements are performed to quantify various phases present in amorphous and semi-crystalline polyester samples uniaxially drawn above their respective glass transition temperature. Results show the appearance of a crystalline phase induced by stretching and of a part of the amorphous phase which does not participate in glass transition. The existence of this phase—called rigid amorphous phase—is enhanced by the presence of crystallites rather than by the drawing.