Novel Styrene−Butadiene Copolymers by Ring-Opening Metathesis Polymerization

The possibilities offered by the ring-opening metathesis polymerization (ROMP) of macromonomers were exploited to arrange polystyrene (PS) and polybutadiene (PB) subchains in various topologies. PS n - b -PB m and PS n - co -PB m miktoarm stars were obtained by sequential and statistical polymerization of norbornene-terminated PS and PB macromonomers, whereas (PS- b -PB) n star block copolymers were derived by homopolymerization of the corresponding macromonomers via ROMP. Umbrella-type and dumbbell-shaped copolymers are two other architectures that were prepared through the sequential ROMP of ω-norbornenyl PS macromonomer and cyclooctadiene.