Hierarchical Morphologies Formed by ABC Star-Shaped Terpolymers

Abstract

Three types of hierarchical morphologies, i.e., cylinders-in-lamella, lamellae-in-cylinder, and lamellae-in-sphere structures, have been identified for ABC star-shaped terpolymers by transmission electron microscopy and small-angle X-ray scattering. The samples are composed of polyisoprene (I), polystyrene (S), and poly(2-vinylpyridine) (P) whose volume ratios of I:S:P are 1.0:1.8: X, where X covers the range 4.3 ≤ X ≤ 53. In the cylinders-in-lamella structures, cylinders of the component I in lamellar matrix of S are oriented perpendicular to the lamellar planes, resulting in aligning normal to the film surface, while alternating lamellae of the component I and S are stacked in cylinders along the directions of the cylindrical axes in the lamellae-in-cylinder structures.