Miscibility in cross-linked polymer-solvent systems with nematic interactions

Model phase diagrams of cross-linked polymers and low molecular weight solv ent systems with nematic interactions are discussed. A combination of class ical theories of network elasticity due to cross-links, isotropic mixing wi th solvent, and a nematic interaction of the Maier-Saupe type yields a vari ety of phase behaviors. The network elasticity parameters and the Flory-Hug gins interaction parameter are assumed to be function of the volume fractio n in contrast to our previous studies of analogous systems. Effects of nema tic order on the miscibility of cross-linked polymers and low molecular wei ght LC are discussed by comparison with the corresponding isotropic systems . The case of side chain liquid crystal cross-linked networks and isotropic solvents is also examined within the same theoretical scheme. The influenc e of cross-linking density and the reference polymer volume fraction at cro ss-linking on the phase behavior is also invoked.