SAXS measurements that the star copolymers formed the (AB) n -type star copolymers (arm numbers n Γ
14 and 16; poly-lattice with a body-centered cubic (BCC) structure near the isoprene blocks Γ
23-24 mol%) were prepared by anionic copolyoverlap threshold (C*) (7). The C* is defined as a region merization of polystyrene-block-polyisoprene diblock anions with of crossover between the dilute polymer solution where the divinylbenzene. The structural ordering of such star-block copolycoils are separate and the more concentrated solution region mers was investigated through small-angle X-ray scattering and where the coils overlap. At the C* the coils begins to be electron microscopy. (AB) n -type stars formed a body-centered cudensely packed. However, the ordering process of (AB) n bic (BCC) structure near the overlap threshold (C*). This strucstars through the C* into bulk film is not unclarified.
ture changed to a mixed lattice of BCC and face-centered cubic
In this paper, we prepared the (AB) n star-block polymers (FCC) structure with increasing polymer concentration. Near the bulk, such stars formed a FCC structure. It was concluded that having many arms (n Γ
14 and 16) by copolymerization of (AB) n -type stars led to hierarchical transformation of the cubic PS-block-PI diblock anions with DVB. The self-micellizalattices from the C* threshold into a continuous film. α§ 1998 tion behavior was investigated by dynamic light scattering.
Academic Press
We also examined the process of structural ordering for star-Key Words: (AB) n -type star; cubic lattice; SAXS.
block copolymers through the C* into the bulk film using the SAXS measurements.