Syndiotactic Polystyrene Films: Orientation and Structural Changes Upon Biaxial Drawing

The orientation developed in biaxially stretched sPS (BoSPS) films before and after crystallization is studied using XRD and FT-IR. On BoSPS films, thermal treatment induces crystallization into the trans-planar a-crystalline phase and a planar'' crystalline phase orientation is observed. In contrast, solvent treatments on BoSPS films induce crystallization into the helical delta-crystalline phase, representing the first example of a polymeric framework that is able to absorb low-molecular-mass guest molecules from water and air at low activities and that is promising for applications in chemical separation or water purification applications; in this case a high degree of a(//)c(//) uniplanar'' crystalline phase orientation is observed.