Deformation mechanisms in PBT at elevated temperatures Article - Août 2023

The plastic deformation of Polybutylene terephthalate (PBT) is investigated at three temperatures (120°C, 150°C, 180°C) representative of the span between glass transition, Tg ≈ 55°C and melting Tm ≈ 225°C temperatures. The mechanisms of tensile deformation are analyzed as a function of the true strain using a combination of temperature-controlled tensile experiments coupled with 2D digital image correlation and synchrotron sourced wide angle (WAXS) and small angle (SAXS) X-ray scattering the amorphous and crystalline regions causing the transition between polymorphs, respectively from the isotropic amorphous phase to a smectic phase and from the alpha to beta crystalline phase.