Small- and wide-angle X-ray scattering investigations of injection-moulded polypropylene

The layered structure in 2 mm thick discs injection moulded from industrial polypropylene (PP) was studied by scanning the cross section of the mouldings by means of small- and wide-angle X-ray scattering (SAXS and WAXS), using a Kratky collimation system for position-resolved quantitative scattering measurements in both angular domains. The registration of so-called scattering profiles of the mouldings and a texture analysis of the WAXS profiles were established as novel approaches for studying the cross-section architecture. The results of the investigations comprise statements on the preferential orientation and the local distribution of α- and β-PP in different layers of the cross sections, on crystallite sizes and on the behaviour of individual layers in tensile tests.