Mesomorphic phase formation of poly(macromonomer)s of polystyrene macromonomers

The liquid crystalline phase formation of poly(macromonomer)s associated wi th the specific multibranched architecture of high branch density was inves tigated. The poly(macromonomer)s were prepared by radical chain polymerizat ions of omega-methacryloyloxyethyl polystyrene macromonomers. It was confir med that the mesomorphic phase formation depended on the branching architec ture, where sufficient length of the branch chains as well as the backbone chain is crucial for the formation of the mesomorphic phase. Formation of t he optically anisotropic mesophase also depended on the nature of solvent. The mesophase was observed in se cast films prepared from p-xylene, toluene , tetrahydrofuran, carbon disulfide and chloroform but not observed for cyc lohexane. The effects oft he branched structure and the solvent nature were explained by repulsive interaction between the polystyrene branch chains o f high branch density. The repulsive interaction increases the chain stiffn ess of the central backbone and also prevents the interpenetration of the p olystyrene branches of different molecules in solution, which allow poly(ma cromonomer) molecules to arrange with the orientational order. Copyright (C ) 2000 John Wiley & Sons, Ltd.