Linear viscoelasticity and director dynamics of nematic liquid crystalline polymer melts
Department of Chemical Engineering and Materials Science,
University of Minnesota 421 Washington Ave. S.E., Minneapolis, MN 55455, USA
Corresponding author: firstname.lastname@example.org
Accepted: 4 November 1999
We describe the linear viscoelastic response of monodomains of unentangled nematic liquid crystalline polymers, using a generalized Rouse model. We calculate the dynamic relaxation functions analogous to the Leslie viscosities. As a consequence of the coupling of the macroscopic director orientation to Rouse relaxation of the chain conformations, we predict: 1) a non-monotonic evolution of the director orientation after a step deformation and continuous tumbling in steady shear for extended chains (with no hairpins), and flow alignment of anisotropic Gaussian chains (with many hairpins), and 2) a phenomenon of “director recoil” in the response of to a transient magnetic field.
PACS: 83.10.Nn – Polymer dynamics / 83.70.Jr – Liquid crystals: nematic, cholesteric, smectic, discotic, etc / 83.50.Fc – Linear viscoelasticity
© EDP Sciences, 2000