On the morphological behavior of ABC miktoarm stars containing poly(cis 1,4-isoprene), poly(styrene), and poly(2-vinylpyridine) |
| |
Authors: | Sergey Chernyy Jyoti P Mahalik Rajeev Kumar Jacob Judas Kain Kirkensgaard Matthias M L Arras Hyeyoung Kim Lars Schulte Sokol Ndoni Gregory S Smith Kell Mortensen Bobby G Sumpter Thomas P Russell Kristoffer Almdal |
| |
Institution: | 1. Technical University of Denmark, DTU Nanotech, Produktionstorvet, 2800 Lyngby, Denmark;2. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831;3. Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark;4. Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831;5. Polymer Science and Engineering Department, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003 |
| |
Abstract: | Fundamental understanding of microphase separation in ABC miktoarm copolymers is vital to access a plethora of nonconventional morphologies. Miktoarm stars based on poly(cis 1,4-isoprene) (I), poly(styrene) (S), and poly(2-vinylpyridine) (V) are model systems, which allow systematic studies of the effects of composition, chemical microstructure, and temperature on the thermodynamics of microphase separation. Eleven ISV-x (I:S:V = 1:1:x, v:v:v) miktoarm copolymers were synthesized by anionic polymerization affording well-defined copolymers with a variable V arm. Equilibrium bulk morphologies of all samples, as evidenced by small-angle X-ray scattering, transmission electron microscopy (TEM), and self-consistent field theory, showed a systematic transition from lamellae (x ≈ 0–0.2) to 8.8.4] tiling (x ≈ 0.6–0.9) to cylinders in undulating lamellae (x ≈ 2–4) and, finally, to hexagonally packed core–shell cylinders (x ≈ 5–8). Chemical microstructure of the I arm poly(cis 1,4-isoprene)] versus poly(3,4-isoprene) is shown to play important role in affecting morphological behavior. To reconcile differences between ISV-x star morphologies reported in the literature and those reported herein, even for the same composition, effects of the microstructure of I arm on the Flory–Huggins parameter between I and V arms were taken into account in a qualitative manner. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1491–1504 |
| |
Keywords: | ABC miktoarm stars bis(phenylethenyl)benzene (1 4-PEB) bulk morphology phase transition poly(2-vinylpyridine) (V) poly(isoprene) (I) poly(styrene) (S) |
|
|