Mechanical Reinforcement by Interfacial Layer in Phase-separating Associating Telechelic Polymers

ORAL

Abstract

Associating polymers capable of forming reversible bonds exhibit macroscopic properties (e.g. unique viscoelastic behavior, self-healing capability etc.), which are governed by their microstructure. Here, we investigate the structure and dynamics of short telechelic PDMS polymers with H-bonding end groups. Small angle X-ray scattering measurements indicate phase separation (clustering of functional end groups) due to the polarity difference between polymer backbone and sticky end groups. The presence of the clusters significantly alters the viscoelastic behavior of these materials, resulting in extremely long rubbery plateau. Using dielectric spectroscopy and an approach developed earlier for polymer nanocomposite, we estimate the thickness of an interfacial polymer layer around these clusters. The dynamics of this interfacial layer is almost an order of magnitude slower than segmental dynamics of bulk-like polymer. Using the interfacial layer model (ILM) analysis, we find that shear modulus of this interfacial polymer layer is ~100 MPa. Our analysis reveals that phase-separating telechelic associating polymers are quite similar to polymer nanocomposites, and interfacial layer plays a critical role in their mechanical and viscoelastic properties.

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Presenters

  • Subarna Samanta

    Department of Chemistry, University of Tennessee, Knoxville, USA, Department of Chemistry, university of Tennessee

Authors

  • Subarna Samanta

    Department of Chemistry, University of Tennessee, Knoxville, USA, Department of Chemistry, university of Tennessee

  • SIRUI GE

    Department of Materials Science and Engineering, University of Tennessee, Knoxville, USA, Materials Science and Engineering, University of Tennessee

  • Martin Tress

    Peter Debye Institute for Soft Matter Research, Leipzig University, Leipzing, Germany, Department of Chemistry, university of Tennessee

  • Bingrui Li

    Department of Chemistry, University of Tennessee, Knoxville, USA

  • Kunyue Xing

    Department of Chemistry, University of Tennessee, Knoxville, USA, Department of Chemistry, university of Tennessee

  • Peng-Fei Cao

    Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, USA, Chemical Sciences Division, Oak Ridge National Laboratory

  • Alexei Sokolov

    Oak Ridge National Lab, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA, Oak Ridge National Laboratory, University of Tennessee, Department of Chemistry, University of Tennessee, Knoxville, USA, Department of Chemistry, university of Tennessee