Anomalous surface relaxations of branched-polymer melts.

Phys Rev Lett

Department of Polymer Science, The University of Akron, Akron, Ohio 44325-3909, USA.

Published: August 2013

The dynamics of thermally stimulated surface fluctuations of 100 nm thick films of long-branched polymers are measured for the first time. In contrast to comparable films of linear or cyclic chains that show no change in viscosity upon confinement, films of 6-pom, 6-star, and 6-end end-branched stars show viscosities, inferred from x-ray photon correlation spectroscopy, as much as 100 times higher than in the bulk. This difference varies in magnitude with chain architecture. Branching has a profound effect on confinement, even for these unentangled chains.

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http://dx.doi.org/10.1103/PhysRevLett.111.068303DOI Listing

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