0000000000371337
AUTHOR
Ulrike Breiner
Structural Characterization of the “Knitting Pattern” in Polystyrene-block-poly(ethylene-co-butylene)-block-poly(methyl methacrylate) Triblock Copolymers
In a polystyrene-block-polybutadiene-block-poly(methyl methacrylate) triblock copolymer (SBM) a morphological transition from a lamellar (ll) morphology (with sequence ABCB) to the knitting pattern (kp) morphology occurs upon hydrogenation of the center PB block. Structural information of the nonhydrogenated and the hydrogenated material is provided from small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). For the nonhydrogenated SBM sample the SAXS profile correlates well with a simple periodic lamellar structure. The hydrogenated sample forming the kp morphology displays a more complex SAXS pattern. From the TEM images of the knitting pattern the two-dimensional…
Organometallic ABC-triblock copolymers
The interaction of Fe and Pd complexes with double bonds of the polybutadiene (PB) block in polystyrene-polybutadiene-poly(methyl methacrylate) block copolymers has been studied. The incorporation of Fe(CO)3 fragments into the PB bloc was found to result in an increase in its rigidity. The presence of iron or palladium complexes in the PB block affects strongly the morphology of the triblock copolymers.
Evolution of the “knitting pattern” morphology in ABC triblock copolymers
A new morphology of ternary ABC triblock copolymers is presented which results from the asymmetric interaction between a centre block (poly(ethylene-co-butene)) to different end blocks (polystyrene and poly(methyl methacrylate)). This morphology with the appearance of a “knitting pattern” can be described as an intermediate of a morphology of A, B and C lamellae and a morphology of A and C lamellae with B cylinders at the A/C interface.
Cylindrical morphologies in asymmetric ABC triblock copolymers
In asymmetric ABC triblock copolymers with C being the matrix-forming majority component, the formation of cylindrical morphologies is governed by the sum of the volume fractions of the components A and B (Φ A + Φ B ) as well as by their ratio (Φ B /Φ A ). The paper describes the morphologies of various polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (SBM) and polystyrene-block-poly(ethylene-co-butylene)-block-poly(methyl methacrylate) block copolymers (SEBM) in dependence on these parameters. In addition to previously reported cylinder in cylinder (c i c, core shell) and helical (hel) morphologies, new microphase separated structures as cylinders at cylinder (c a c), undula…