Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 2: Polymer Physics I
CPP 2.1: Vortrag
Montag, 26. März 2007, 10:00–10:15, H40
Multiscale modeling of block-copolymer-nanomaterials — •Stephan Alexander Baeurle1, Takao Usami2, and Andrei Gusev3 — 1Department of Chemistry and Pharmacy, Institute of Physical and Theoretical Chemistry, University of Regensburg, D-93053 Regensburg, Germany — 2Polymer Design Laboratory, Mitsubishi Chemical Group Science and Technological Research Center, Yokkaichi, Mie 510-0885, Japan — 3Department of Materials, Institute of Polymers, ETH, CH-8093, Zurich, Switzerland
A detailed knowledge about the physics and chemistry of multiphase materials on different length and time scales is essential to tailor their macroscopic physical and mechanical properties. A better understanding of these issues is also highly relevant to optimize their processing and, thus, their elucidation can be determinant for their final industrial application. In this presentation we introduce an analytical and numerical multiscale modeling approach, to explain and predict the peculiar stress relaxation behavior of block-copolymer-based thermoplastic elastomers at long times, which are subjected to a nonlinear extensional strain. We compare our theoretical results to the stress relaxation measurements performed on poly(styrene-isoprene-styrene) triblock copolymers and show that they correctly describe the crossover from power-law to stretched-exponential relaxation behavior, observed below the glass transition temperature of the polystyrene crosslinks. Our study confirm the importance of the chain-pullout mechanism in the stress relaxation process and demonstrates the involvement of multiple time- and structural-length-scales.