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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 23: Poster: Polymer Dynamics
CPP 23.8: Poster
Wednesday, March 28, 2012, 11:00–13:00, Poster A
Influence of pressure on deviations of chain dynamics from the Rouse model: A molecular dynamics simulation study of poly(dimethylsiloxane) and polybutadiene melts. — •Patrick Henritzi1, Dmitry Bedrov2, Grant Smith2, and Michael Vogel1 — 1Intitut für Festkörperphysik, TU Darmstadt, 64289 Darmstadt, Germany — 2Department of Material Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA
Molecular dynamics simulations of poly(dimethylsiloxane) (PDMS) and polybutadiene (PBD) melts have been performed as a function of pressure. At atmospheric pressure the single-chain coherent dynamic structure factor of PBD exhibited greater deviation from ideal Rouse behavior than PDMS, in agreement with neutron spin echo (NSE) measurements. Chain dynamics in both PDMS and PBD exhibited increasing deviations from Rouse predictions with increasing pressure. These deviations were found to correlate with the free volume fraction in the melt, implying that inter-chain correlations and not intrinsic rotational barriers are mainly responsible for non-ideal chain dynamics in polymer melts.