Star-shaped polymers with a doubled fullerene (C60) branching center

Star-shaped regular homopolystyrenes with 22 arms and heteroarm polymers with 12 PS arms and 10 poly(2-vinypyridine) arms have been synthesized by consecutive coupling-functionalization-coupling reactions. The synthesis includes the following stages: the exhaustive grafting of fullerene C₆₀ by polystyryllithium chains (living hexaadducts); the coupling of hexaadducts with the use of dimethyldichlorosilane or 1,4-dibromobutane into twelve-arm macromolecules, where the branching center is composed of two covalently bonded fullerene C₆₀ molecules; functionalization of twelve-arm double-core PS stars during the action of excess dihalides (the replacement of lithium atoms with groups containing chlorine or bromine atoms); and the coupling of living chains of PS or poly(2-vinylpyridine) via reactions with halogen-containing groups at the branching center of double-core PS stars. Linear living polymers used as arms have been prepared by anionic polymerization. Exclusion chromatography has been used to control the individual stages of synthesis. The molecular characteristics of the PS precursor and of star-shaped polymers have been studied in terms of hydrodynamics and light scattering.