Regensburg 2010 – wissenschaftliches Programm
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SYMR: Symposium Nuclear Magnetic Resonance: from Applications in Condensed-Matter Physics to New Frontiers
SYMR 6: Polymer Dynamics
SYMR 6.7: Vortrag
Mittwoch, 24. März 2010, 11:45–12:00, H48
Understanding the Origin of Dynamical Heterogeneities in Polymer Blends — •Diddo Diddens1,2, Andreas Heuer1,2, and Martin Brodeck3 — 1Institut für physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 30, 48149 Münster, Germany — 2NRW Graduate School of Chemistry, Corrensstraße 36, 48149 Münster, Germany — 3Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
Polymer blends composed of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) have been the focus of many investigations such as neutron scattering or NMR experiments. Within this polymer blend both components have greatly different glass transition temperatures, so that the low-Tg compound (PEO) moves in a random, nearly frozen environment imposed by the high-Tg compound (PMMA), leading to strong dynamical heterogeneities within the PEO dynamics. One common approach to model the dynamics of the PEO chains is the phenomenological Random-Rouse Model, in which the random environment imposed by the slow PMMA component is modelled by a Rouse chain with different friction coefficients on each bead.
Here we discuss the merits and limitations of the Random-Rouse Model for a simulated PEO/PMMA blend. By using a recently developed method to determine local mobilities in polymeric systems, we can check the different assumptions of this model. Moreover, the length-scale dependence of the retardation of the PEO dynamics in the blend compared to the homopolymer was studied.
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