Synthesis and morphology of ABC heteroarm star terpolymers of polystyrene, polybutadiene and poly(2-vinylpyridine)

Abstract

Three series of ABC heteroarm star terpolymers with arms of polystyrene (S), polybutadiene (B) and poly(2-vinylpyridine) (V) were synthesized anionically using non-homopolymerizable macromonomers functionalized with a terminal 1,1-diphenylethylene unit. Ultrathin samples from solution cast films were stained with OsO4, CH3I or I2 and studied by transmission electron microscopy (TEM). The morphologies found include dense packings of cylinders with tetragonal or distorted hexagonal order, two hexagonal morphologies with V cylinders surrounded by six B and six S cylinders, where S and V switch places depending on the polymer composition, lamellae of V and S with B cylinders in the S lamella and smooth lamellae of all components. Some polymers were also characterized by small angle X-ray scattering (SAXS).