Preparation and characterization of cyclic polystyrene with short poly(2‐<i>tert</i>‐butylbutadiene) sequences

Takano, Atsushi; Nonaka, Atsushi; Kadoi, Osamu; Hirahara, Kazuro; Kawahara, Seiichi; Isono, Yoshinobu; Torikai, Naoya; Matsushita, Yushu

doi:10.1002/polb.10183

Cited by 30 publications

(31 citation statements)

References 18 publications

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“…For cyclic DBCP consisting of long PS and short poly(tertbutyl butadiene) blocks, no phase separation was observed and the characterization was found on the hydrodynamic properties in solution. 304 However, for cyclic PS-poly(2-vinyl pyridine) DBCPs and their parent triblock copolymers phase separation was observed in the solid state. TEM and SAXS measurements revealed a ratio of domain spacings Ds c /Ds l around 0.91 in analogy to other PS-DBCPs.…”

Section: Nanophase Separation Of Cyclic Diblock Copolymersmentioning

confidence: 99%

“…Almost all authors who worked on syntheses and characterization of cyclic DBCPs 75,80,81,83,91,[93][94][95][300][301][302][303][304][305] were interested in the phenomenon of phase separation. It is long known that nearly all polymers of different structure (even if the difference is small, e.g., polyethylene/polypropylene) are not miscible in the melt, because the entropy of mixing is too low.…”

Section: Nanophase Separation Of Cyclic Diblock Copolymersmentioning

confidence: 99%

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Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

400

442

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Syntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun-shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring-ring equilibration, or ring-expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed.

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Section: Nanophase Separation Of Cyclic Diblock Copolymersmentioning

confidence: 99%

Section: Nanophase Separation Of Cyclic Diblock Copolymersmentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

400

442

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“…Only for the low molecular weight cyclic polymers, the detailed cyclic structures were directly confirmed by NMR analysis of linking points, 22,23 pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), 31 and matrix-assisted laser desorption/ionization timeof-flight (MALDI-TOF) mass spectrometry. 29 Recently, Takano et al have reported on preparation and characterization of cyclic polystyrenes with short poly(2-tert-butyl-butadiene) sequence and proposed a novel method, ozonolysis-GPC analysis, 32 to prove the purity of cyclic molecule.…”

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confidence: 99%

Preparation and Characterization of Cyclic Polystyrenes

Cho

Masuoka

Koguchi

et al. 2005

Polym J

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ABSTRACT:Macrocyclic polystyrenes with various molecular weight were prepared by the reaction of linear polystyrene having two end vinyl groups and potassium naphthalenide as a coupling agent. Intermolecular side reactions produced higher molecular weight polycondensates and undesirable chain termination reactions also produced linear precursors in addition to the designed molecules. In order to isolate cyclic polymers from the ring closure reaction mixtures, preparative size exclusion chromatography (SEC) method was employed. The purity of SEC-fractionated cyclic polystyrenes was rigorously examined by liquid chromatography at the critical condition (LCCC) and interaction chromatography (IC). After SEC-fractionation, we obtained large amount of highly pure cyclic polymers, though high molecular weight cyclic polymers contain very small amount of linear precursor (< 5%). The purity and isotope effect on reversed-phase liquid chromatography (RPLC) were also rigorously investigated by preparing a deuterated cyclic polystyrene. [DOI 10.1295/polymj.37.506] KEY WORDS Cyclic Polystyrene / GPC Fractionation / LCCC / Isotope Effect / Cyclic macromolecules are of great interest in the investigation of the influence of cyclization on their solution, melt, and solid-state properties. Various physical properties of cyclic polymers have been predicted not only by theoretical methods 1-4 but also by computer simulation studies, 5-7 while they have also been examined experimentally. [8][9][10][11][12][13][14] Cyclic polymers were usually synthesized by the coupling reaction between living precursor polymers with functional groups on both ends and bifunctional linking agents. For example, polystyrenes 9,15-19 and poly(2-vinylpyridine)s 20,21 have been synthesized by this method. Furthermore, , !-heterobifunctional polymers have been used for the synthesis of cyclic polymers.22-24 However, side reactions produce linear precursor polymers, and intermolecular reactions simultaneously produce dimeric and higher molecular weight linear polycondensates. Therefore, it is very difficult to obtain pure cyclic polymers directly, and fractionation is necessary in order to obtain cyclic polymers with high purity. For the isolation of cyclic polymers from the ring closure reaction mixtures, two major fractionation methods have been employed: fractional precipitation method 9,14,[16][17][18] and preparative size exclusion chromatography (SEC). 25,26 Furthermore, liquid chromatography at the critical condition method (LCCC) has been successfully applied for the characterization of cyclic polymers.27-30 Throughout these experimental studies, however, the direct evidence of cyclic structure was not shown, in addition to the fact that the purity of the cyclic molecules has not been determined quantitatively in most of the works. Only for the low molecular weight cyclic polymers, the detailed cyclic structures were directly confirmed by NMR analysis of linking points, 22,23 pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), 31 and matri...

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“…The second model polymer is two-component cyclic block copolymer composed of polystyrene and polyisoprene [32,33]. The molecular weight dependence of microdomain spacing has been investigated and it has found that chain elongation along the direction perpendicular to lamellar interface is suppressed considerably because of all loop conformation of cyclic molecules whose both ends are tethered to microdomain interface.…”

Section: Control Of Hierarchical Structures Of Soft Materialsmentioning

confidence: 99%

Advances in nature-guided materials processing

Asai

Koumoto

Matsushita

et al. 2003

Science and Technology of Advanced Materials

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The center of excellence (COE) titled 'The Creation of Nature-Guided Materials Processing' has been established in Nagoya University as the 21st Century COE Program supported by Ministry of Education, Culture, Sports, Science and Technology. In the Nature COE, various activities on the education and research are being performed through learning the laws of nature, namely, methods of attaining 'appearance of the maximum function under the minimum substance and energy consumption', which the nature and living organisms have acquired through their evolution in long period. Together with such educational programs for PhD students as research incentive, oversea training, and external evaluation programs, an 'Open-Cluster Program' was originated for promoting researches proposed by research groups consisting of young researchers in and out of the university and also for fostering them.The researches are being advanced on materials used for living bodies, mimicking structures which nature or living bodies are forming, and producing materials by mimicking processes to form the structures observed in the nature or the living bodies. In this COE, these researches are conducted by four groups to extend the processes observed in the natural world to a new type of processing, that is, thoroughly examined and rationalized by plunging a scalpel of engineering and to establish a new academic field of materials science and engineering. q

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Preparation and characterization of cyclic polystyrene with short poly(2‐tert‐butylbutadiene) sequences

Cited by 30 publications

References 18 publications

Cyclic polymers: Synthetic strategies and physical properties

Cyclic polymers: Synthetic strategies and physical properties

Preparation and Characterization of Cyclic Polystyrenes

Advances in nature-guided materials processing

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