Session B25: Polymer Blends

11:15 AM–2:03 PM, Monday, March 10, 2008
Morial Convention Center - 217

Sponsoring Unit: DPOLY
Chair: Rick Register, Princeton University

Abstract ID: BAPS.2008.MAR.B25.4

Abstract: B25.00004 : Flory Theorem for Structurally Asymmetric Mixtures

11:51 AM–12:03 PM

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Authors:

  Andrey Dobrynin
    (Institute of Materials Science, University of Connecticut)

  Frank Sun
    (Department of Chemistry, University of North Carolina at Chapel Hill)

  David Shirvanyants
    (Department of Chemistry, University of North Carolina at Chapel Hill)

  Gregory Rubinstein
    (Department of Chemistry, University of North Carolina at Chapel Hill)

  Michael Rubinstein
    (Department of Chemistry, University of North Carolina at Chapel Hill)

  Sergei Sheiko
    (Department of Chemistry, University of North Carolina at Chapel Hill)

  Hyung-Il Lee
    (Department of Chemistry, Carnegie Mellon University)

  Krzysztof Matyjaszewski
    (Department of Chemistry, Carnegie Mellon University)

The generalization of the Flory theorem for structurally asymmetric mixtures was derived and tested by direct visualization of conformational transformations of brushlike macromolecules embedded in a melt of linear chains. Swelling of a brush molecule was shown to be controlled not only by the degree of polymerization of the surrounding linear chains, \textit{NB}, but also by the degree of polymerization of the brush's side chains, $N$, which determines the structural asymmetry of the mixed species. The boundaries of the swelling region were established by scaling analysis as $N^2$ $<$\textit{NB} $<$\textit{NA/N}, where \textit{NA} is the degree of polymerization of the brush backbone. Experiment and theory demonstrated good agreement.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.MAR.B25.4