Get access
Advertisement

Near-surface dynamics of sheared polymer melts using ATR/FTIR

Authors

  • Geoffrey M. Wise,

    1. Materials Sciences Division, Lawrence Berkeley National Laboratory and Dept. of Chemical Engineering, University of California at Berkeley, Berkeley, CA 94720
    Search for more papers by this author
  • Morton M. Denn,

    Corresponding author
    1. Materials Sciences Division, Lawrence Berkeley National Laboratory and Dept. of Chemical Engineering, University of California at Berkeley, Berkeley, CA 94720
    • Materials Sciences Division, Lawrence Berkeley National Laboratory and Dept. of Chemical Engineering, University of California at Berkeley, Berkeley, CA 94720
    Search for more papers by this author
  • Alexis T. Bell

    1. Materials Sciences Division, Lawrence Berkeley National Laboratory and Dept. of Chemical Engineering, University of California at Berkeley, Berkeley, CA 94720
    Search for more papers by this author

Abstract

Using attenuated total-reflectance infrared spectroscopy (ATR/FTIR), the concentration of deuterated polybutadiene near the surface of a flat zinc selenide crystal was followed as it was replaced by ordinary polybutadiene by flow and diffusion. Experiments were performed in the melt, both below (M ∼ 1,500) and above (M ∼ 15,000) the entanglement threshold. The decay profiles agree well with a finite-element simulation of the system. In contrast to previous investigations of C16's, the decay profiles of both unentangled and entangled polybutadienes are consistent with a uniform diffusivity in the near-wall region.

Get access to the full text of this article

Ancillary