Solvent Polarity Effects on Segmental Dynamics in Ionic Polymer Networks: Quasi Elastic Neutron Scattering Study

ORAL

Abstract

Incorporating ionic groups into polymers drives formation of physical networks that affect the dynamics of the macromolecules. Here, using quasi elastic neutron scattering (QENS), segmental dynamics of slightly sulfonated (3mol%) polystyrene (PSS) networks formed in cyclohexane, a non-polar environment and a theta solvent for PS was studied, followed by tracking the polymer motion as the association of the sulfonated groups is disrupted by ethanol. Specifically, a 10%(w/w) PSS in cyclohexane/ethanol solutions was studies in the q range of 0.3 Å-1 to 1.3 Å-1 corresponding to 5 Å -21 Å. The relaxation times and segmental motion were extracted from a Kohlrausch-Williams-Watts (KWW) analysis. As expected for PSS in cyclohexane, the dynamics is constrained at larger dimensions but the polymer remains mobile on smaller length scales. Addition of less than 5%(v/v) of ethanol is enough to release the constrains. Surprisingly however, further increase in ethanol results in decrease in segmental motion. This reduction could be attributed to overall plasticization of the polymer in presence of ethanol.

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Presenters

  • Supun Samindra Mohottalalage

    Department of Chemistry, Clemson University, Clemson, SC, United States.

Authors

  • Supun Samindra Mohottalalage

    Department of Chemistry, Clemson University, Clemson, SC, United States.

  • Sidath Wijesinghe

    Department of Chemistry, Clemson University, Clemson, SC, United States., Chemistry, UNC Chapel Hill

  • Manjula Senanayake

    Department of Chemistry , Clemson University, Clemson, SC, United States,29634, Department of Chemistry, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Chemistry, Clemson University, Clemson, SC, United States., Chemistry, Clemson University

  • Chathurika Kosgallana

    Department of Chemistry, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Chemistry, Clemson University, Clemson, SC, United States., Chemistry, Clemson University

  • Naresh Osti

    Oak Ridge National Laboratory, Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge National Laboratory, Oak Ridge, TN, United States., Neutron Scattering Division, Oak Ridge National Laboratory

  • Dvora Perahia

    Department of Chemistry/Department of Physics, Clemson University, Clemson, SC, United States, 29634, Clemson University, Department of Chemistry/ Department of Physics, Clemson University, Clemson, SC, United States, Department of Chemistry, Clemson, SC, 29634, United States, Clemson University, Department of Physics, Clemson, SC, 29631, United States, Clemson University, Department of Chemistry/Department of Physics, Clemson University, Clemson, SC, United States., Chemistry, Physics, Clemson University