ATRP−RCM Synthesis of Cyclic Diblock Copolymers

Adachi, K.; Honda, Satoshi; Hayashi, Shotaro; Tezuka, Yasuyuki

doi:10.1021/ma801363n

Cited by 75 publications

(77 citation statements)

References 52 publications

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“…[100][101][102][103][104] Cationic polymerization of THF followed by incorporation of two allyl-ether endgroups yielded suitable linear precursors. 100,101 Scheme 25 illustrates the synthesis of a ''defect-free'' cyclic poly THF.…”

Section: -1351-70mentioning

confidence: 99%

“…Their metathesis condensation with elimination of ethylene yielded under high dilution the desired cyclic diblock copolymers. 104 Finally, it should be mentioned that cyclic PS was also prepared by oxidative coupling of mercapto groups (Scheme 27). 105 The telechelic PS was prepared by radical polymerization, so that originally two dithioester endgroups were obtained, which liberated the mercapto groups by aminolytic cleavage of the SACS bond.…”

Section: -1351-70mentioning

confidence: 99%

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Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

399

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: -1351-70mentioning

confidence: 99%

Section: -1351-70mentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

399

442

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“…39 These allyl-telechelics were then subjected to a metathesis clip reaction under dilution to effectively produce both cyclic homopolymers and block copolymers, including an amphiphilic poly (butyl acrylate)-b-PEO and polystyrene-b-PEO. [37][38][39] Remarkably, a micelle formed from the obtained cyclic amphiphile exhibited significantly enhanced thermal stability in comparison with that of its linear counterpart. 40 This finding is regarded as the first example of an amplified topology effect by a synthetic cyclic polymer upon self-assembly (Scheme 4).…”

Section: Current Synthetic Challenges For Cyclic Polymersmentioning

confidence: 94%

“…[33][34][35] We have developed an effective unimolecular polymer cyclization process with symmetric olefinic-telechelics, which are conveniently obtainable through the direct end-capping reaction of a variety Topological polymer chemistry Y Tezuka of living polymers. 36 The quantitative conversion of the atom transfer radical polymerization-terminal bromoalkyl group into allyl groups was achieved with allyltributylstannane (Keck allylation) for polyacrylates 37,38 and with allyltrimethylsilane/TiCl 4 for polystyrene. 39 These allyl-telechelics were then subjected to a metathesis clip reaction under dilution to effectively produce both cyclic homopolymers and block copolymers, including an amphiphilic poly (butyl acrylate)-b-PEO and polystyrene-b-PEO.…”

Section: Current Synthetic Challenges For Cyclic Polymersmentioning

confidence: 99%

Topological polymer chemistry for designing multicyclic macromolecular architectures

Tezuka

2012

Polym J

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The geometrical conception and current synthetic challenges of topological polymer chemistry have been reviewed. On the basis of the systematic classification and isomeric properties of polymer chain topologies, a variety of novel multicyclic macromolecular constructions have now been rationally designed and subsequently realized by intriguing synthetic protocols. In particular, cyclic and multicyclic polymer products are effectively produced by an electrostatic polymer self-assembly of telechelic precursors that contain cyclic ammonium salt groups accompanying polyfunctional carboxylate counteranions and the subsequent covalent conversion through the ring-opening or through the ring-emitting reaction of the cyclic ammonium salt groups by carboxylate counteranions (Electrostatic Self-assembly and Covalent Fixation (ESA-CF) process). Furthermore, the ESA-CF process, in conjunction with effective linking/cleaving chemistry (including the metathesis condensation (clip) and alkyne-azide addition (click) reactions), has been demonstrated as a new synthetic protocol for unprecedented multicyclic macromolecular topologies.

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“…30 Thus first, an A-B type allyl-telechelic diblock copolymer comprised of two different acrylate ester segments, i.e., poly(methyl acrylate)-b-poly(butyl acrylate), has been prepared via the ATRP of methyl acrylate by allyl bromide as an initiator, followed by the addition of the second monomer, butyl acrylate, and with allyltributylstannane as an end-capping reagent. Alternatively, an A-B-A type allyl-telechelic triblock copolymer comprised of poly(butyl acrylate) and poly(ethylene oxide), poly(EO), segments has been prepared via the ATRP of butyl acrylate using a poly(EO) macroinitiator having 2-bromoisobutyryl end groups, followed by the end-capping reaction by the Keck allylation.…”

Section: Atrp--rcm For New Cyclic and Multicyclic Polymer Architecturesmentioning

confidence: 99%

Topological Polymer Chemistry in Pursuit of Elusive Polymer Ring Constructions

Adachi

Tezuka

2009

J. Synth. Org. Chem. Jpn.

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Current challenges and future perspectives of topological polymer chemistry have been reviewed. A variety of novel cyclic and multicyclic macromolecular topologies has now been realized by intriguing synthetic protocols. In particular, the electrostatic polymer self-assembly of telechelic precursors having cyclic ammonium salt groups accompanying polyfunctional carboxylate counteranions has been exploited in dilution to produce topologically significant, non-covalent constructions of a dynamic nature. The subsequent covalent conversion through the ring-opening or through the ring-emitting reaction of cyclic ammonium salt groups by carboxylate counteranions provides cyclic and multicyclic polymer products effectively. Furthermore, the metathesis condensation process with functional cyclic polymer precursors has been demonstrated as a promising synthetic means to construct a variety of complex polymer topologies. Scheme 1. Single and multicyclic polymer topologies (ring family tree).tive properties in comparison with conventional linear or branched polyethylenes. 7a The "end-biting" chain transfer to eliminate the initiator species is a key to producing stable ring polymers. However, the chain transfer occurs concurrently during the propagation, and the chain length distribution (MWD) of the polymer products could not be controlled rigorously. By this ring-expansion process using a bulky, dendronized monomer, a ring-shaped nano-object has also been produced. 7e Ring poly(sulfide)s, free of the initiator fragment and having controlled size distributions have also been reported, in which the repetitive insertion of thiirane, a three-membered cyclic sulfide monomer into the thioester unit of a cyclic initiator proceeds with the concurrent chain transfer by intermolecular ester exchange reactions.7f More recently, ring polyesters with narrow size distributions have been obtained by a zwitterionic ring-opening polymerization of cyclic lactones and lactides with an N-heterocyclic carbene initiator (Scheme 2).7g-i In this process, the "end-biting" chain transfer is assumed to take place after the rapid propagation to eliminate the initiator species. Furthermore, ring-expansion polymerization has been combined with the end-linking reaction for the practical synthesis of ring polymers of high molar mass (Scheme 2). 10Thus, a cyclic initiator of stannous dialkoxide has been employed for the ring-opening polymerization of e-caprolactone. By taking advantage of the living nature of this process, a few units of a photo-crosslinkable, acrylate-functionalized e-caprolactone derivative have subsequently been introduced. Thereafter the intramolecular photo-crosslinking of acrylic groups has been conducted under dilution, and the stannous dialkoxide initiator fragment has finally been removed by hydrolysis, to produce ring polymers free of the initiator fragments.10a By this process, a twin-tail tadpole polymer comprised of a ring and two outward branch segments, has also been prepared by the re-initiation of ring-ope...

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ATRP−RCM Synthesis of Cyclic Diblock Copolymers

Cited by 75 publications

References 52 publications

Cyclic polymers: Synthetic strategies and physical properties

Cyclic polymers: Synthetic strategies and physical properties

Topological polymer chemistry for designing multicyclic macromolecular architectures

Topological Polymer Chemistry in Pursuit of Elusive Polymer Ring Constructions

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