Regensburg 2010 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 31: Poster: Polymer Dynamics
CPP 31.12: Poster
Mittwoch, 24. März 2010, 17:30–19:00, Poster C
Micromechanics of Thin Films of Elastomeric Polypropylene — •Martin Neumann1, Mechthild Franke1, Andreas Schoebel2, and Robert Magerle1 — 1Chemische Physik, TU Chemnitz, D-09107 Chemnitz — 2WACKER-Lehrstuhl für Makromolekulare Chemie, TU München, D-85747 Garching
We present a micro-tensile testing setup that allows imaging with scanning force microscopy (SFM) the deformations within the microstructure of approximately 1 μm thick polymer films. This allows correlating directly the micromechanical behavior of a polymeric specimen with its macroscopic stress-strain behavior. In elastomeric polypropylene, a semicrystalline polymer with only 12% crystallinity, we image the deformation behavior of individual crystalline lamellae upon straining and relaxation. Our data shows a large variety of phenomena: bending, kink formation and fragmentation of individual lamella, fixed branching angles between lamellae, as well as locally auxetic behavior of certain crystal complexes. The stress-strain behavior is viscoelastic with elastic moduli in the range between 0.2 to 2 MPa and two relaxation time constants of about 10 s and 300 s, similar as measured for macroscopic specimens.