Microdomain morphologies, block

Sakurai S., Kawada H., Hashimoto T., and Fetters L.J. Thermoreversible morphology transition between spherical and cyUndrical microdomains of block copolymers. Macromolecules, 26, 5796, 1993. 

Unlike the bulk morphology, block copolymer thin films are often characterized by thickness-dependent highly oriented domains, as a result of surface and interfacial energy minimization [115,116]. For example, in the simplest composition-symmetric (ID lamellae) coil-coil thin films, the overall trend when t>Lo is for the lamellae to be oriented parallel to the plane of the film [115]. Under symmetric boundary conditions, frustration cannot be avoided if t is not commensurate with L0 in a confined film and the lamellar period deviates from the bulk value by compressing the chain conformation [117]. Under asymmetric boundary conditions, an incomplete top layer composed of islands and holes of height Lo forms as in the incommensurate case [118]. However, it has also been observed that microdomains can reorient such that they are perpendicular to the surface [ 119], or they can take mixed orientations to relieve the constraint [66]. 

Note 2 Microdomain morphologies are usually observed in block, graft, and segmented copolymers. 

Figure 15. Concept of microphase stabilized ferroelectric liquid crystal (MSFLC). The black domain represents the coil block. Only lamellar microdomain morphology is shown in the figure. The FLC supramolecular pitch is unwound by the block microdomain [109, 130],...

C.D. Han, D.M. Baek, J. Kim, K. Kimishima, T. Hashimoto, Viscoelastic behavior, phase-equilibria, and microdomain morphology in mixtures of a block copolymer and a homopolymer, Macromolecules 25 (1992) 3052-3067. 

Thomas EL, Alward DB, Kinning DJ, Martin DC, Handlin D Jr, Fetters LJ (1986) Ordered bicontinuous double-diamond stmcture of star block copolymers—a new equilibrium microdomain morphology. Macromolecules 19(8) 2197-2202... 

In present study, we employed both SAXS and theological measurements to investigate the order-disorder and order-order transitions in a series of SIS triblock copolymer/low molecular weight PS homopolymer mixtures, which did not show macrophase separation in the whole temperature and composition range covered in this experiment, Phase diagrams obtained from both measurements were compared with the predictions based on the Whitmore-Noolandi theory. The difference between the theory and the experiment was discussed in terms of the change in homopolymer distribution and microdomain morphology by the addition of homopolymer to block copolymer. 

Changes in Equilibrium Microdomain Morphology of Block Copolymers with the Addition of PS... 

It is well known that a block copolymer shows multiple X-ray scattering peaks due to its periodic microdomain structure having a long-range order Information on the equilibrium microdomain morphology of block copolymers can be obtained from the relative positions of these multiple peaks, since they exhibit different arrays depending on the shape of the microdomain structure, e.g., 1, 2, 3,4,... for lamellae,... 

Koberstein, J. X, Galambos,A. R, Leung, L. M. (1992), Compression-molded polyurethane block copolymers. 1. Microdomain morphology and thermomechanical properties. Macromolecules, 25, 6195-204. 

Koberstein, J. T., Leung, L. M. (1992), Compression-molded polyurethane block copolymers. 2. Evaluation of microphase compositions, Macwmo/ecw/es, 25,6205-13. Koberstein, J. T., Galambos, A. F., Leung, L. M. (1992), Compression-molded polyurethane block copolymers, Part 1 Microdomain morphology and thermo-mechanical properties. Macromolecules, 25, 6195-204. 

Systematic smdies on the microdomain morphology of linear ABC Mblock terpolymers (hereafter called linear ABC) are limited to several systems. Linear ABC samples were predominantly synthesized by sequential living anionic polymerizations, which limit the kinds of monomers. Thus, polystyrene (PS) and polyisoprene (PI) or polybutadiene (PB) as well as their hydrogenated polymers such as poly(ethylene-a/t-propylene) (PEP) or poly(ethylene-aft-butylene) (PEB) were used as the A and B blocks, while poly(2-vinylpyridine) (P2VP), poly(4-vinylpyridine) (P4VP), poly(methyl methacrylate) (PMMA), poly(tert-buthyl methacrylate) (PtBMA), poly(ethylene oxide) (PEO) or polydimethylsiloxane (PDMS) was used as... 

An ABC miktoarm star terpolymer has a configuration of a C polymer grafted at the junction point of an AB diblock copolymer as depicted in Figure 18.1c, and hereafter we call it p-ABC. Since it is not necessary to account for the order of the sequences of A, B and C blocks in a p-ABC, ithas fewer variables to designate the system than a linear ABC. However, because of the unusual molecular architecture of a p-ABC whose three different block chains possess the same junction, the microdomain morphologies it can take become quite different from those of a linear ABC when they microphase-separate into three phases. (In this chapter, we only consider the three-phase structures.) Three microphases of a p-ABC must meet in space to... 

Hasegawa, H., Tanaka, H., Yamasaki, K., andHashimoto, T. (1987) Bicontinuous microdomain morphology of block copolymers. 1. Tetrapod-network strucmre of polystyrene-polyisoprene diblock polymers. Macromolecules, 20,1651-1662. 

Lee W, Chen HL, Lin TL. Correlation between crystalhzation kinetics and microdomain morphology in block copolymer blends exhibiting confined crystalhzation. J Polym Sci B Polym Phys 2002 40(6) 519-29. 

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