Influence of acrylate arm topology on phase diagrams of mixtures of multiarm acrylate photocurative monomers and nematic liquid crystals

Phase equilibria of binary mixtures of liquid crystal and multiarm star acrylate derivatives have been established as a function of the number of acrylate arms by means of cloud point determination. Equilibrium phase diagrams of liquid crystal/multiarm acrylate derivatives have been calculated self-consistently in the framework of combined Flory-Huggins free energy of liquid-liquid demixing and Maier-Saupe free energy of nematic ordering. It was found experimentally that the phase diagram of the branched/star molecule/solvent shifts to elevated temperatures with an increasing number of acrylate arms. This movement of the coexistence line is attributed to the architectural effect contributing to the athermal entropic part of the chi interaction parameter. The present self-consistent solution has been tested satisfactorily with the observed phase diagrams of liquid crystal/acrylate systems.