Berlin 2008 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 29: Polymerphysics I

CPP 29.2: Vortrag

Donnerstag, 28. Februar 2008, 09:45–10:00, C 130

Changing the fracture properties of Polypropylene by blending — •Stefan Fischer¹, Dirk Doser¹, Tobias Diesner², Bernhard Rieger², and Othmar Marti¹ — ¹Institute of Experimental Physics, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm, Germany — ²Wacker-Lehrstuhl für makromolekulare Chemie, TU München, Lichtenbergstraße 4, 85747 Garching, Germany

Isotactic Polypropylene is among the most widely used plastics. Still it suffers from brittleness at ambient conditions. By enhancing it's fracture properties it could substitute other structures stabilizing solids while introducing it's own advantages like low weight and ductility to high ranges. Therefore in industrial polymers different additives are used to soften the polymer, reducing the brittleness. Still the polymers tend to break easily.

Our research has shown, that blending commercially available Polypropylene with high molecular one we can access new ranges in mechanical stability under certain conditions. The high molecular weight iPP seems to facilitate and propagate the reorientation of crystalline material while suppressing the evolution of cracks. This prevents the fracture at low elongations and allows high stresses and elongations until failure.

We will show the results of tensile tests, SAXS (Small Angle X-Ray Scattering), WAXS (Wide Angle X-Ray Scattering), DSC (Differential Scanning Calorimetry) and AFM (Atomic Force Microscopy) measurements. The effect of high molecular Polypropylene will be discussed, the problems still appearing at ambient conditions will be addressed.