Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 3: Polymer Materials

CPP 3.6: Vortrag

Montag, 27. März 2006, 11:30–11:45, ZEU 114

The study of the relation between cavitation and micro-fibrillation in HDPE using time resolved synchrotron X-ray scattering during tensile deformation — •Konrad Schneider¹, Sondes Trabelsi², Stamm Manfred¹, and Riekel Christian³ — ¹Leibniz-Institut für Polymerforschung Dresden, Hohe Str. 6, 01069 Dresden — ²Forschungszentrum Karlsruhe GmbH, Institut für Synchrotronstrahlung, ANKA, Hermann-von-Helmholtz-Platz 1, 76344 Karlsruhe — ³European Synchrotron Radiation Facility (ESRF), BP 220, F38043 Grenoble, France

Real time synchrotron Small-Angle and Wide-Angle X-ray Scattering was performed during the tensile deformation of a high-density polyethylene copolymer. The changes of the structure in the crystalline and in the amorphous domains were followed during the three characteristic stages of the load-displacement curves: The elastic stage and the plastic stage composed of the phase of the lowering load in the force-displacement-curve and the strain hardening. Competitive phenomena like crystallite fragmentation and cavitations were found to occur simultaneously in the lowering phase of the load but at different length scale. We prove that the volume fraction of the voids increase during the fibrillation of the lamellae stacks. At increasing strain the changes of the radius of gyration of the cavities in stretching as well as in transversal direction were discussed. During strain hardening no further increase in the volume fraction of the voids was found. However, we make evidence for the establishment of a new long spacing order of the micro-block crystallites, which were stable despite the occurrence of the melting process.