Authors
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Serghei, A. ; Mikhailova, Y. ; Eichhorn, K.-J. ; Voit, B. ; Kremer, F.
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Title
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Molecular dynamics of hyperbranched polyesters in the confinement of thin films
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Date
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22.09.2005
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Number
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12997
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Abstract
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Broadband Dielectric Spectroscopy is employed to investigate the molecular dynamics in thin films of hyperbranched polyesters (type AB1B2, with -OH and -OCOCH3 as terminal groups). Three relaxation processes are detected: alpha, beta and gamma. While the latter two are not influenced by the confinement, a pronounced effect is observed on the alpha relaxation: with decreasing film thickness the slower relaxation modes of the dynamic glass transition are gradually suppressed, resulting in an increase of the average relaxation rate and in a linear decrease of the dielectric strength. This is attributed to an immobilization in confinement of the polymeric segments located at the periphery of the hyperbranched macromolecular structures.
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Publisher
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The European Physical Journal E - Soft Matter
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Wikidata
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Citation
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The European Physical Journal E - Soft Matter 17 (2005) 199-2002
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DOI
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https://doi.org/epje/i2005-10009-7
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Tags
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glass-transition temperature polymer-films terminal groups polystyrene relaxation surface
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