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

Three series of ABC heteroarm star terpolymers with arms of polystyrene (S) , polybutadiene (B) and poly(2-vinylpyridine) (V) were synthesized anionica lly using non-homopolymerizable macromonomers functionalized with a termina l 1,1-diphenylethylene unit. Ultrathin samples from solution cast films wer e stained with OsO4, CH3I and I-2 and studied by transmission electron micr oscopy (TEM). The morphologies found include dense packings of cylinders wi th 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 cyl inders in the S lamella and smooth lamellae of all components. Some polymer s were also characterized by small angle X-ray scattering (SAXS).