Shear-induced orientation transitions in triblock copolymer styrene-butadiene-styrene with cylindrical domain morphology

Shear-induced alignment of phase-separated domains was studied by TEM and SAXS in a SBS triblock copolymer with a phase-separated morphology of hexagonally packed cylinders of poly(styrene) in a poly(butadiene) matrix. Starting with an ordered structure, where the cylinders were aligned with a common director throughout the sample, a shear flow perpendicular to this director was found to rotate the cylinder orientation by 90° into the shear direction. At all observed strains, the hexagonal faces preferred to orient parallel to the shear plane