Lamellar domain spacing of the ABB graft copolymers

Matsushita, Yushu; Momose, Hikaru; Yoshida, Yoshiki; Noda, Ichiro

doi:10.1016/s0032-3861(96)00475-2

Cited by 23 publications

(24 citation statements)

References 12 publications

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“…The third category is asymmetric lamellar structures as shown in Figure (g,h). Needless to say, the reason (b) mentioned above holds for this simple structure, the same phenomenon was reported previously for the simplest branched polymers of the AB 2 type …”

Section: Discussionsupporting

confidence: 84%

“…Due to advances in polymer synthesis, well‐defined miktoarm star and block‐graft copolymers were prepared and their microphase separated structures have been studied. Up to now, the experimental studies on AB 2, AB 3, AB 5, and AB 10 copolymers have been conducted, and results observed are mostly in reasonably good agreement with those of simulation, although totally new structures such as hexagonal assembly of hexagons, a sort of the Voronoi cell assembly, or σ‐phase have not yet been found in their experimental system. Throughout the experiments mentioned above, systematic morphological works on AB n copolymers with high n , especially more than five, over the wide range of composition have not been carried out, probably because of the difficulty in the syntheses of the copolymers with the complex molecular architectures.…”

Section: Introductionmentioning

confidence: 68%

“…Needless to say, the reason (b) mentioned above holds for this simple structure, the same phenomenon was reported previously for the simplest branched polymers of the AB 2 type. 29 The forth one is inverse cylindrical structure with I-cylinders in the matrix of long S chain. The block-graft copolymers of SI 5 -0.86 and SI 7 -0.90 show hexagonally packed cylindrical structures, where the cross sections of the polyisoprene cylindrical domains are close to ovals, as shown in Figure 2(i,j).…”

Section: Common Origin Of Unusual Morphologiesmentioning

confidence: 99%

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Preparation and Morphologies of AB6¯ Block‐Graft Copolymers

Watanabe

Asai

Takano

et al. 2019

J Polym Sci B Polym Phys

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Microphase‐separated structures of a series of AB6 block‐graft copolymers were studied by TEM and SAXS. Ten copolymers with the same polystyrene (S) backbone and six polyisoprene (I) grafts on the average but with different graft chain lengths were carefully synthesized by living anionic polymerization, covering the range 0.21 ≤ ϕS ≤ 0.90, where ϕS denotes polystyrene compositions. From TEM observation of the AB6 block‐graft copolymers, it turns out to be clear that they show four microphase‐separated structures, S‐spheres, S‐cylinders(S‐prisms), alternative lamellae, and I‐cylinders. Among them, for example, the samples with 0.54 ≤ ϕS ≤ 0.58 shows prism structures whose cross sections of the S domains are close to hexagons, not circles, due to packing frustration of grafts. Composition dependence of morphologies of the present AB6 block‐graft copolymers reveals their phase diagram is extremely asymmetric with respect to ϕS = 0.5. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 952–960

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Section: Discussionsupporting

confidence: 84%

Section: Introductionmentioning

confidence: 68%

Section: Common Origin Of Unusual Morphologiesmentioning

confidence: 99%

See 1 more Smart Citation

Preparation and Morphologies of AB6¯ Block‐Graft Copolymers

Watanabe

Asai

Takano

et al. 2019

J Polym Sci B Polym Phys

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“…It is because the average composition is 0.50 which meets the condition of the extinguishment of the second-order peak for the case of lamellar microdomains. 55 Note that the peak breadth did not change as a function of temperature for the neat MS11 and MS5/MS17 (50/50) blend specimens. Furthermore, it should be noted that the reflection peaks are wider for the binary blend as compared to the neat block (see the SAXS profiles shown in Figure 4b).…”

Section: Resultsmentioning

confidence: 92%

Versatile Controls of Microdomain Morphologies and Temperature Dependencies in Lamellar Spacing by Blending Diblock Copolymers Bearing Antisymmetric Compositions

et al. 2017

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The morphologies of the microphase-separated structures in the binary blends of diblock copolymers (AB/AB) have been studied intensively for the case of diblock copolymers bearing antisymmetric compositions with similar molecular weights. Here, the two diblock copolymers 1 and 2, of which compositions are 0.5 – x and 0.5 + x (0 < x < 0.5), respectively, were blended, and the morphology diagram was constructed in the plot of χ Z vs the average composition of the A component, where χ is the interaction parameter between A and B segments and Z is the average degree of polymerization of the two AB diblock copolymers. The temperature-dependent morphologies were analyzed by synchrotron small-angle X-ray scattering (SAXS) measurements. It was found that the morphology diagram agrees in principle with the theoretical one for the neat AB diblocks by Matsen and Bates ( Macromolecules 1996 , 29 , 1091–1098), although the disordered phase was a bit expanded in the experimentally determined morphology diagram. Anomalous temperature dependencies in the lamellar spacing have been also comprehensively studied for the binary blends of antisymmetric diblock copolymers as a function of the degree of compositional asymmetry by closely adjusting the average composition in the blend specimen at 0.50. For this purpose, more than 20 neat diblock copolymers have been synthesized with a wide range of compositions from 0.20 to 0.87 and a range of molecular weight of 12 000–33 800. The temperature dependencies of the lamellar spacing were also analyzed by synchrotron SAXS measurements. As a result, the following things were found. The scaling exponent α in D ∼ T α was still negative but slightly larger than the usual value (i.e., α = −0.33) for the smaller degree of asymmetry in the composition (i.e., x is small), while α became positive for the higher degree of asymmetry. The latter result is very anomalous because the temperature dependence is opposite (i.e., the lamellar spacing increases with an increase of temperature). The value of α was found to be linearly rationalized with the degree of asymmetry τ (which is especially introduced in the current paper for this purpose), for the binary blends with the average composition of 0.50. Based on this result, one can prepare lamellar microdomains, of which spacing does not change with temperature, by blending two diblock copolymers with τ = 1.33 (corresponding to 0.3 and 0.7 of compositions) having similar molecular weights. This would be important for manufacturing materials with properties (for instance, the optical property) independent of temperature. From the current study, the binary blends of the antisymmetric diblock copolymers are concluded to be versatile such that the precise controls of the morphologies and the temperat...

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“…Other various copolymer systems, such as AB 2 graft copolymers [119][120][121], star-shaped molecules of the (AB) n type [122,123], (AB) n multiblock copolymer systems [124][125][126], AB ring-shaped copolymers [127,128], and ABC star-shaped terpolymers [129][130][131], were also widely studied.…”

Section: Bulk Morphologiesmentioning

confidence: 99%

Dynamic Assembly of Block-Copolymers

Quémener¹,

Deratani²,

Lecommandoux³

2011

Constitutional Dynamic Chemistry

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Block copolymers (BCs) are well-known building blocks for the creation of a large variety of nanostructured materials or objects through a dynamic assembly stage which can be either autonomous or guided by an external force. Today's nanotechnologies require sharp control of the overall architecture from the nanoscale to the macroscale. BCs enable this dynamic assembly through all the scales, from few aggregated polymer chains to large bulk polymer materials. Since the discovery of controlled methods to polymerize monomers with different functionalities, a broad diversity of BCs exists, giving rise to many different nanoobjects and nanostructured materials. This chapter will explore the potentialities of block copolymer chains to be assembled through dynamic interactions either in solution or in bulk.

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Lamellar domain spacing of the ABB graft copolymers

Cited by 23 publications

References 12 publications

Preparation and Morphologies of AB6¯ Block‐Graft Copolymers

Preparation and Morphologies of AB6¯ Block‐Graft Copolymers

Versatile Controls of Microdomain Morphologies and Temperature Dependencies in Lamellar Spacing by Blending Diblock Copolymers Bearing Antisymmetric Compositions

Dynamic Assembly of Block-Copolymers

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