Volume 28, Issue 14 pp. 1455-1465
Feature Article

NMR Reveals Non-Distributed and Uniform Character of Network Chain Dynamics

Kay Saalwächter

Corresponding Author

Kay Saalwächter

Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Friedemann-Bach-Platz 6, D-06018 Halle, Germany

Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Friedemann-Bach-Platz 6, D-06018 Halle, Germany.Search for more papers by this author
Jens-Uwe Sommer

Jens-Uwe Sommer

Leibniz-Institut für Polymerforschung Dresden e. V., Hohe Straße 6, D-01069 Dresden, Germany

Search for more papers by this author
First published: 11 July 2007
Citations: 50

Abstract

Results of different NMR investigations of elastomers are reviewed with respect to their significance for statistical models of rubber elasticity. In contrast to earlier work based on lineshape analysis and relaxometry, results of recent multiple-quantum experiments indicate that the NMR-detected dynamic chain order parameter, which reflects the conformational space of individual monomer units at which the signal is detected locally, is a rather narrowly distributed quantity. Constraints to the dynamics and the conformations of a network chain thus act uniformly and appear as a dynamic average over chains of different length and with different end-to-end separations. All our findings are in good agreement with large-scale computer simulations. Anomalies on swelling such as chain desinterspersion at the early stages and the appearance of heterogeneities, are also discussed.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.