Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 14: Polymer Crystallization
CPP 14.1: Vortrag
Mittwoch, 29. März 2006, 14:00–14:15, ZEU Lich
Deformation and Fracture Mechanisms in Semicrystalline Polymers as revealed by Microfocus Synchrotron X-ray Scattering — •Nikolaos Zafeiropoulos1, Richard Davies2, Christian Riekel2, Yongfeng Men3, Jens Rieger3, and Manfred Stamm1 — 1Leibniz-Institut für Polymerforschung Dresden, Hohe Strasse 6, 01069, Dresden — 2European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France — 3BASF Aktiengesellschaft, Polymer Physics, 67056 Ludwigshafen, Germany
The fracture properties of polymers are one of the key parameters that define their service life and limit their applications. One of the most interesting and important questions is how the molecular architecture and the structure of polymers at nano- length scales influence their fracture properties. X-ray scattering is a powerful means of probing bulk structures at the nanometer scale. It can therefore provide a wealth of information relating to such structure-property relationships. In the present study, synchrotron radiation microfocus small and wide angle X-ray scattering is used to investigate the fracture mechanisms ahead of a crack tip in situ with the application of load, and the damage area ahead and around the crack tip post mortem, in isotactic polypropylene and high density polyethylene samples of different thermal histories. The results revealed that significant cavitation develops in the damage area at the plastically deformed region beyond the crack tip, and inside the damage zone rod and platelet-shaped cracks/voids are formed (as revealed by SAXS), accompanied by martensitic crystal transformations or the formation of a conformationally disordered phase (as revealed by WAXS).