Microdomain morphologies

While thin polymer films may be very smooth and homogeneous, the chain conformation may be largely distorted due to the influence of the interfaces. Since the size of the polymer molecules is comparable to the film thickness those effects may play a significant role with ultra-thin polymer films. Several recent theoretical treatments are available [136-144,127,128] based on Monte Carlo [137-141,127, 128], molecular dynamics [142], variable density [143], cooperative motion [144], and bond fluctuation [136] model calculations. The distortion of the chain conformation near the interface, the segment orientation distribution, end distribution etc. are calculated as a function of film thickness and distance from the surface. In the limit of two-dimensional systems chains segregate and specific power laws are predicted [136, 137]. In 2D-blends of polymers a particular microdomain morphology may be expected [139]. Experiments on polymers in this area are presently, however, not available on a molecular level. Indications of order on an... 

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

Much experimental work has appeared in the literature concerning the microphase separation of miktoarm star polymers. The issue of interest is the influence of the branched architectures on the microdomain morphology and on the static and dynamic characteristics of the order-disorder transition, the ultimate goal being the understanding of the structure-properties relation for these complex materials in order to design polymers for special applications. 

The microdomain morphology of asymmetric miktoarm stars of the type AA B with A, A =PI of different molecular weight and B deuterated PS, covering a wide range of compositions, was investigated by Gido and coworkers [52] by... 

Hashimoto et al. [87] recently reported on the microdomain morphology of three component miktoarm stars, consisting of polystyrene, poly(dimethylsi-loxane) and poly(ferf-butyl methacrylate) with nearly the same fraction of each component. Three distinct microdomains were observed by TEM, a result that was confirmed by DSC experiments which showed three distinct Tgs. The two-dimentional images of the unstained sections showed triangular patterns exhib-... 

Yamauchi K, Takahashi K (2003) Microdomain morphology in an ABC 3-miktoarm star terpolymer a study by energy-filtering TEM and 3D electron tomography. Macromolecules 36 6962-6966... 

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],...

Microdomain size in phase-separated copolymers plays a fundamental role in determining various macroscopic physical properties in the solid state. The difference in segmental mobility between the hard and soft domains governs the physical properties of microphase-separated polyurethane elastomers [7]. In this respect, the development of structure-property relations at the molecular level which relate directly to macroscopic behavior is the focus of this sub-section. One can exploit the well-documented difference between domain mobility [7-10] and the i3C NMR chemical shift distinction between the 0 .H2 resonances in the hard and soft segments to probe the microdomain morphology of polyether-... 

Midtiblock midticomponent polymers have the potential to generate a variety of well-defined and controlled multiphase microdomain morphologies with very small dimensions and/or provide the supramolecular stmctures with a... 

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. 

Politakos, N. Ntoukas, E. Averopoulos, A. Krikorian, V. Pate, B. D. Thomas, E. L. Hfll, R. M., Strongly Segregated Cubic Microdomain Morphology Consistent with the Double Gyroid Phase in High Molecular Weight Diblock Copolymers of Polystyrene and Poly(dimethylsiloxane). J. Polym. Sci., PartB Polym. Phys. 2009,47,2419-2427. 

Mechanical Properties. Liquid crystalline polymers are known to have outstanding mechanical properties due to their microdomain morphology and their ability to be oriented. It is expected, therefore, that LCTs may have the same advantages. The effects of orientation are considered in a later section here we consider only macroscopically imoriented systems. 

Figure 5.3 TEM images of an unstained, microtomed cross-section of a thermally annealed, Co-containing (a) BC (scale bar, lOOnm) and (b) homopolymer (scale bar, lOOnm), showing the cylindrical microdomain morphology of the BC and Co nanoparticles distributed randomly in...

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,... 

---