Morphology of syndiotactic polystyrene as examined by small-angle X-ray scattering

Small Angle X-Ray scattering (SAXS) studies have been carried out on injection molded syndiotactic polystyrene (SPS) at room temperature and at elevated temperatures up to 290 degrees C. Features indicating lamellar crystallinity were weak or entirely absent at room temperature, becoming increasingly Intense above the glass transition temperature (T-g) for this material. A background scattering whose intensity was roughly proportional to q(-2), where q is the scattering momentum transfer, was present throughout the temperature range. We suggest that these results indicate that SPS materials formed in this way are three-phase systems, with an amorphous phase, a crystalline phase, and a grain boundary phase.