Influence of an oriented glassy cylindrical microdomain structure on the morphology of crystallizing lamellae in a semicrystalline block terpolymer

The effect of an oriented microphase-separated structure, induced by an applied flow bias field (roll casting), on the crystallization of the polyethylene (PE) block in a semicrystalline polystyrene-block-(polyethylene-alt-propylene)-block-polyethylene terpolymer has been analyzed. The orientation and morphology of the emerging crystals with respect to the preexisting glassy cylindrical microdomain structure has been investigated by simultaneous wide-angle and small-angle X-ray scattering and transmission electron microscopy. The oriented hexagonally packed cylinders induce oriented crystallization of the PE block in the matrix upon slow cooling below the crystallization temperature. The texture which develops has the b and c axes of the PE crystals predominantly parallel and perpendicular to the PS cylinder axes, respectively. The lateral packing of the PS cylinders is disrupted by the crystallization, but the longitudinal orientation of the cylinders is maintained.