Phase Equilibria of Flexible Polymer and Monomer Liquid Crystal Blends

Abstract

In this study, we explored the phase equilibria in blends of a nematic liquid crystal monomer and a nematic liquid crystal flexible polymer within the whole composition of the phase diagram. The crystal-nematic and nematic-isotropic transition temperatures, as well as the transition enthalpies and entropies, indicated the total miscibility in this mesogenic blend system. We also extracted an empirical axial ratio of 4.52 for the polymer from the nematic-isotropic transitions of the blends. Further, from the biphasic nematic-isotropic transitions of the blends in low concentration regions, we estimated the entropies of pure monomer and polymer from a theoretical lattice model. The calculated and experimental results showed good agreement. This work will be continued with a more detailed study of phase equilibria and comparison with other theoretical models in nematic flexible polymer and non-mesogenic rigid-rod monomer blends will be made.