Interpretation of the observed influence of mesophase structures on the ?-relaxation in side chain liquid crystal polymers

Abstract

A strong dependence of the rotational dynamics of the mesogenic units (β-relaxation) on the order of the mesophase was found in sidechain liquid crystal polymers. The preexponential frequency factor, \documentclass{article}\pagestyle{empty}\begin{document}$ f_{\beta \infty }^* $\end{document} and the activation energy \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm E}_{\alpha \beta }^{\rm *} $\end{document} of the β-relaxation rate both increase significantly (i.e., obeying a compensation law) with increasing order of the mesophase which is accompanied by a decrease of the mean lateral mesogenic distance. In this work, we show how these experimental results can be interpreted in a quantitative manner by using the general results of the coupling model for cooperative motions. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1927–1934, 1998