Structure Formation of Metallopolymer-Grafted Block Copolymers

Microphase separation drives the structure formation in block copolymers. Here, functional metallopolymer-grafted diblock copolymers consisting of polystyrene-block-polyisoprene (PS-b-PI) as polymer backbone featuring low molar mass poly­ferrocenyl­dimethyl­silane (PFS) and polyvinyl­ferrocene (PVFc) are synthesized via an iterative anionic grafting-to polymerization strategy. PS-b-PI block copolymers having about 30 mol % 1,2-polyisoprene moieties are subjected to platinum-catalyzed hydrosilylation reaction for the introduction of chlorosilane groups. The Si–Cl moieties are shown to efficiently react with the active metallopolymers yielding block-selective metallopolymer-grafted copolymers with 34 vol % PVFc and 43 vol % PFS as evidenced by 1H NMR spectroscopy as well as size exclusion chromatography. The microphase separation of the functional metallopolymer-grafted block copolymers is evidenced via TEM measurements revealing fascinating morphologies. The structure formation of the PVFc-grafted block copolymers is studied in more detail by TEM, small-angle X-ray scattering, wide-angle X-ray scattering, and atomic force microscopy measurements evidencing a lamellar morphology featuring a spherical substructure for the PVFc segments inside the polyisoprene lamellae.