Cylindrical morphologies in asymmetric ABC triblock copolymers

Breiner, U.; Krappe, Udo; Abetz, Volker; Stadler, Reimund

doi:10.1002/macp.1997.021980411

Cited by 182 publications

(214 citation statements)

References 15 publications

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“…However, if more than two monomer types are involved microphase separation frequently occurs at more than one length scale [1][2][3][4][5][6][7]. Several examples, that are of direct interest for the present paper, can be found in the experimental work of Ikkala and Ten Brinke and co-workers [4][5][6].…”

Section: Introductionmentioning

confidence: 92%

Ordering at Two Length Scales in Comb−Coil Diblock Copolymers Consisting of Only Two Different Monomers

Nap

Brinke²,

Brinke³

2002

Macromolecules

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The microphase separated morphology of a melt of a specific class of comb-coil diblock copolymers, consisting of an AB comb block and a linear homopolymer A block, is analyzed in the weak segregation limit. On increasing the length of the homopolymer A block, the systems go through a characteristic series of structural transitions. Starting from the pure comb copolymer the first series of structures involve the short length scale followed by structures involving the large length scale. A maximum of two critical points exists. Furthermore, in the two parameter space, characterizing the comb-coil diblock copolymer molecules considered, a non-trivial bifurcation point exists beyond which the structure factor can have two maxima (two correlation hole peaks).

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Section: Introductionmentioning

confidence: 92%

Ordering at Two Length Scales in Comb−Coil Diblock Copolymers Consisting of Only Two Different Monomers

Nap

Brinke²,

Brinke³

2002

Macromolecules

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“…This type of polymers consists of three blocks which can differ from each other (ABC) [28][29][30][31][32][33][34][35][36][37] or can have two similar blocks (ABA) [37][38][39][40][41][42][43]. Numerous studies on synthesis of triblock copolymers via anionic as well as controlled radical polymerization have been published.…”

Section: Introductionmentioning

confidence: 99%

Influence of block sequence and molecular weight on morphological, rheological and dielectric properties of weakly and strongly segregated styrene-isoprene triblock copolymers

Georgopanos

Handge

Abetz

et al. 2016

Polymer

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In this work, morphological, thermal, viscoelastic and dielectric properties of triblock copolymers consisting of styrene (S) and isoprene (I) blocks are discussed. SIS and ISI triblock copolymers were synthesized by sequential anionic polymerization, three of them exhibiting molecular weights below the entanglement molecular weight M e , three of them exhibiting molecular weights in the order of M e and two of them exhibiting molecular weights above M e . The objective of this work is the investigation of the influence of molecular weight and block sequence on relaxation of the block copolymer chains. Morphological investigations using small angle X-ray scattering and transmission electron microscopy studies reveal that a larger molecular weight is associated with a more pronounced microphase separation. The presence of two glass transition temperatures reveals microphase separation of the PI and PS blocks. The Fox-Flory equation was applied in order to describe the molecular weight dependence of the glass transition temperature of the polyisoprene and the polystyrene blocks. The analysis of rheological data reveals a Maxwell fluid behaviour for the weakly segregated block copolymers, whereas for the strongly segregated block copolymers a pronounced elastic behaviour at low frequencies of small amplitude shear oscillations was observed.In the intermediate regime of molecular weight, a complex viscoelastic behaviour appears. The plateau modulus G N o is influenced by the sequence of the PS and the PI blocks (SIS or ISI). Our analysis of segmental and normal mode relaxation in dielectric spectroscopy experiments show that the relaxation processes are strongly influenced by the block sequence (PI blocks tethered at one or 1 both ends) and the molecular weight. As a result, the block sequence in triblock copolymers influences dynamical properties in the glassy state and in the melt.

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“…5(a) and (b)). This morphology, referred to as 'coral snake' aggregates, has never been observed until now for micellar systems at least to the best of our knowledge, although it was previously reported in the bulk [11][12][13]. It consists of a rod-like core surrounded by regularly spaced rings.…”

Section: Fig 2 Rod-like Aggregates Of Ps 200 -B-p2vp 140 -B-peo 590mentioning

confidence: 57%

Dependence of the structure of core–shell–corona micelles on the composition of water/toluene mixtures

Liangcai

Gohy

Willet

et al. 2006

Polymer

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The poly(styrene)-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) triblock copolymer, PS , where the subscripts refer to the average degrees of polymerisation of the constitutive blocks, has been dissolved in water/toluene mixtures with a large range of composition, i.e. in (i) toluene added with a small amount of water, (ii) water-in-toluene emulsion forming mixtures, (iii) toluene-in-water emulsion forming mixtures, and (iv) water added with a small amount of toluene. These solutions have been cast on a carboncoated copper grid, and the morphology of the dried copolymer deposition has been observed by transmission electron microscopy. Rod-like aggregates with a core-shell-corona micellar structure are formed in cases (i) and (iv). Nevertheless, PEO is the core and PS is the corona in case (i), whereas the reverse situation prevails in case (iv). When an emulsion is the precursor of the dried copolymer aggregates, either onion-like structures (case ii) or vesicles mixed with more complex aggregates are formed (case iii). These structures are thought to reflect the self-organization of the PS 200 _ b-P2VP 140 -b-PEO 590 copolymer at the water/toluene interface of the water-intoluene and toluene-in-water emulsions, respectively.

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Cylindrical morphologies in asymmetric ABC triblock copolymers

Cited by 182 publications

References 15 publications

Ordering at Two Length Scales in Comb−Coil Diblock Copolymers Consisting of Only Two Different Monomers

Ordering at Two Length Scales in Comb−Coil Diblock Copolymers Consisting of Only Two Different Monomers

Influence of block sequence and molecular weight on morphological, rheological and dielectric properties of weakly and strongly segregated styrene-isoprene triblock copolymers

Dependence of the structure of core–shell–corona micelles on the composition of water/toluene mixtures

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