Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 24: Poster: Polymer Dynamics

CPP 24.6: Poster

Dienstag, 15. März 2011, 18:00–20:00, P2

Rotational and translational diffusion in hyperbranched polyglycerols — •Tilman Schubert, Joshua Rume Sangoro, Ciprian Iacob, and Friedrich Kremer — Institute of Experimental Physics I, University of Leipzig, Linnéstr. 5, 04103 Leipzig, Germany

Molecular dynamics of hyperbranched polyglycerols of different molecular weights is studied by Broadband Dielectric Spectroscopy (BDS). The results for the characteristic quantities (structural alpha-relaxation rate and diffusion rate) are combined with the findings of PFG-NMR, rheology and calorimetry. Three different dielectric relaxation processes are observed. Upon application of Maxwell's relation to the rheology data structural relaxation rates are obtained corresponding to the slowest dipolar relaxation from BDS measurements. Extrapolated to lower temperatures, agreement is found with the glass transition temperatures measured by DS calorimetry. The results are discussed within the framework of recent theories of the dynamic glass transition.