Liquid Crystalline Rod−Coil Block Copolymers by Stable Free Radical Polymerization: Synthesis, Morphology, and Rheology

摘要: We have synthesized and characterized rod−coil diblock, triblock, starblock copolymers of controlled molecular weight by stable free radical polymerization, where the rod part consists “mesogen jacketed liquid crystalline segments” (MJLCP). The MJLCP segment examined in our studies is poly{2,5-(4-butylbenzoyl)oxystyrene} (PBBOS) while coil poly(styrene). SAXS block at room temperature predominantly show only a first-order maximum their spectra. Above Tg two blocks (∼150 °C) no phase-separated morphology could be detected temperature-dependent measurements copolymers. Slow cooling regenerates morphology, indicating very slow ordering kinetics. effects variation architecture increasing topological constraint going from homopolymer to star copolymer on melt rheology (i.e., viscosity, relaxation times, activation energies) are reported. In master curves all ...