Heating scans of stretched polystyrene films with stable baselines: Preparation method of samples for thermal analysis

Abstract

Differential scanning calorimetry (DSC) examinations were carried out for stretched polystyrene (PS) films. A specific sample preparation technique was developed to overcome the entropic shrinkage, which makes DSC baselines unstable and divergent with each other. As a result, the data were acquired for stretched PS film with stable baselines overlayable below and above glass transition temperature shoulder. This method enables us to observe shoulder shift and evaluate the area bounded by two heat flow curves with and without both thermal ageing and stretching.