Block copolymer blends morphologies

Jiang S, Gopfert A, Abetz V. Novel morphologies of block copolymer blends via hydrogen bonding. Macromolecules 2003 31 6171-6177. 

In a first step we prepared block copolymer blend samples. Blending with a large amount of the homopolymer will inevitably led to a spherical morphology, but we need to investigate whether the photophysical behavior of the minority segment is maintained or changed. 

Grafted block copolymer blends Divers The soluble polymer usually was the matrix with the other resins forming isolated domains. Physical properties and morphology IMerret, 1957 Beecher et aL, 1969 Inoue et al., 1960 Pedemonte et aL, 1975 Kraus and RoUman, 1976 Kawai et al., 1971]... 

Tang, C., Hur, S., Stahl, B.C., Sivanandan, K., Dimitriou, M., Pressly, E., Fredrickson, G.H., Kramer, E.J., Hawker, C.J. Thin film morphology of block copolymer blends with tunable supramolecular interactions for lithographic applications. Macromolecules 43, 2880 (2010)... 

Stimulated by the finding of noncentrosymmetric superlattices in block copolymer blends also the possibility to generate this morphology by a pure A-B-C-A tetrablock terpolymer was investigated and found [247]. Here the difference between the interfacial tensions between A, B and A, C might be the major controlling parameter for the formation of this morphology. 

Studies of block copolymer blends where one of the blocks is common to each of the block copolymers include PS-b-Pl with PS-b-EP [701], PS-b-PI with PI-b-PEO [702], and PS-b-PI with PS-b-P2VP [703]. Macrophase separation is often observed, but conditions exist where microphase separation results with imique morphologies. 

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. 

Morphologies obtained in homopolymer/block copolymer blends depending on the molecular weight of the homopolymer employed. 

Adhikari R, Michler GH, Henning S, Godehardt R, Hny TA, GoerlitzS, et al. Morphology and micromechanical deformation behavior of styrene-bntadiene block copolymers. IV. Structnre-property correlation in binary block copolymer blends. J Appl Polym Sci 2004 92 1219-30. 

As with AB/AC diblock copolymer blends, the principal reasons for exploring the phase behaviour of AB/ABC block copolymer blends are the possibilities of (i) generating the wide variety of elegant morphologies already afforded by... 

Takano et al. investigated an ABCA tetrablock terpolymer (ISVI) of isoprene, styrene, 2-vinylpyridine, and isoprene aiming for a periodic noncentrosymmetric lamellar morphology. They synthesized the tetrablock terpolymer by coupling two living diblock copolymers (IS and IV, respectively). This work was stimulated by the observation of a periodic noncentros)mimetric lamellar superstracture in a block copolymer blend, which will be discussed later. A hierarchical stmrture of lamellae was observed for a... 

As more complex multicomponent blends are being developed for commercial appHcations, new approaches are needed for morphology characterization. Often, the use of RuO staining is effective, as it is sensitive to small variations in the chemical composition of the component polymers. For instance PS, PC, and styrene—ethylene/butylene—styrene block copolymers (SEES) are readily stained, SAN is stained to a lesser degree, and PET and nylons are not stained (158,225—228). 

Butadiene copolymers are mainly prepared to yield mbbers (see Styrene-butadiene rubber). Many commercially significant latex paints are based on styrene—butadiene copolymers (see Coatings Paint). In latex paint the weight ratio S B is usually 60 40 with high conversion. Most of the block copolymers prepared by anionic catalysts, eg, butyUithium, are also elastomers. However, some of these block copolymers are thermoplastic mbbers, which behave like cross-linked mbbers at room temperature but show regular thermoplastic flow at elevated temperatures (45,46). Diblock (styrene—butadiene (SB)) and triblock (styrene—butadiene—styrene (SBS)) copolymers are commercially available. Typically, they are blended with PS to achieve a desirable property, eg, improved clarity/flexibiHty (see Polymerblends) (46). These block copolymers represent a class of new and interesting polymeric materials (47,48). Of particular interest are their morphologies (49—52), solution properties (53,54), and mechanical behavior (55,56). 

---