Microdomain structure of poly(styrene‐4‐vinylpyridine) diblock copolymers

A series of AB and BAB type poly(styrene‐4‐vinylpyridine) diblock copolymers with a sharp distribution of molecular weights were synthesized to study relationships between the molecular weight and domain size of lamellar and spherical microdomains. The domain sizes of diblock copolymer specimens cast from chloroform or 1,1,2‐trichloroethane were estimated from transmission electron micrographs. As a result, the lameller domain spacings, predicted from Halfand's theory, agree well with the experimental results. The radius of spherical domains is far below the theoretical values predicted from Helfand's theory, though.