Topological polymer chemistry for designing multicyclic macromolecular architectures

Tezuka, Yasuyuki

doi:10.1038/pj.2012.92

Cited by 62 publications

(43 citation statements)

References 55 publications

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“…(a) Ring-closure reaction (b) Ring-expansion polymerization [53] Several reviews focus on the synthetic strategies [54][55][56], which are beyond the scope of the present work. To illustrate the two main types of cyclization synthetic methodologies, poly(ε-caprolactone) (PCL) has been selected as an example because cyclic PCLs have been synthesized by both ring-closure reactions and ring-expansion polymerizations.…”

Section: Types Of Cyclic Polymersmentioning

confidence: 99%

Crystallization of Cyclic Polymers

Pérez-Camargo

Múgica

Zubitur

et al. 2015

Polymer Crystallization I

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The effect of chain topology (ring versus linear polymer chains) on polymer crystallization is reviewed. Recent advances in ring closure and ring expansion synthetic techniques have made available a range of well-characterized samples with higher levels of purity than available decades ago. Cyclic molecules are fascinating because the structural difference between them and linear chains is relatively small, yet their behavior can be completely different from that of their linear analogs of identical chain length. The effect of having no chain ends can dramatically change the polymer coil conformation and diffusion rate, as well as the chain entanglement density in the melt. These changes are reflected in different nucleation and crystallization kinetics for cyclic and linear polymeric chains. However, the results published so far seem to be dependent on the type of polymer employed. Therefore, a careful look at the literature and evidence reported for each group of materials has been assembled and compared. The possible reasons for some of the contradictions in the evidence are also discussed.

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Section: Types Of Cyclic Polymersmentioning

confidence: 99%

Crystallization of Cyclic Polymers

Pérez-Camargo

Múgica

Zubitur

et al. 2015

Polymer Crystallization I

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“…47 Inspired by this work, we have attempted the synthesis of cyclo-it-PMMA from a telechelic PMMA with vinyl groups at the both ends by olefin-metathesis reaction. 48,49 The telechelic it-PMMA (it-7m) was prepared through two step reactions; an isotacticspecific polymerization of MMA was initiated by a lithium enolate of ethyl 2-methylpent-4-enoate and terminated with 1a to afford it-7 (Mn = 5100, Mw/Mn = 1.24, F = 96%, mm/ mr/ rr = 96 / 4 / 0), followed by the thiol-ene reaction with 2g (Scheme 5). The obtained telechelic polymer, it-7m, was refluxed with the first generation Grubbs' catalyst in CH2Cl2 (1.0 × 10 −4 M) for 4 days.…”

Section: Attempted Synthesis Of Cyclic Polymermentioning

confidence: 99%

Synthesis and post-polymerization reaction of end-clickable stereoregular polymethacrylates via termination of stereospecific living anionic polymerization

et al. 2015

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ARTICLE This journal is © The Royal Society of Chemistry 2013J. Name., 2013, 00, 1-3 | 1 Poly(methyl methacrylate)s with high stereoregularity and clickable end-groups were synthesized via terminating reactions with α-(halomethyl)acrylates in stereospecific living anionic polymerization. The terminating reaction was so efficient and tolerant to the reaction conditions that almost quantitative end-functionalization was achieved in isotactic-and syndiotactic-specific polymerization systems. The terminating reactions were also achieved in the polymerizations of vinyl methacrylate and trimethylsilyl methacrylate. For the polymerization of butyl acrylate, however, the termination efficiency was limited as high as 69%. Further quantitative end-functionalization of the incorporated C=C double bond at ω-end was achieved with various thiols catalyzed by Et3N. The base-catalysed thiol-ene reaction of the stereoregular poly(vinyl methacrylate) with ω-end C=C double bond proceeded selectively to retain vinyl ester functions, and the subsequent hydrolysis afforded ω-functional stereoregular poly(methacrylic acid). A combination of the terminating agent with a protected lithium amide afforded stereoregular poly(methyl methacrylates) with orthogonally clickable α-and ω-ends.

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“…[56][57][58] Although cyclic polymers have attracted much interest in both polymer synthesis and physics, the synthesis of cyclic polymers has long suffered from the difficulties of tedious preparation and troublesome purification. 12,59,60 Generally, the synthesis of cyclic polymers is accomplished using two major methods: the cyclization of linear-shaped precursors with a homo or hetero bifunctional group Topology-transformable polymers T Takata and D Aoki at both ends and ring expansion polymerization through the continuous addition of monomers to the cyclic initiator. Although the cyclization of linear-shaped precursors is the most commonly used method, it requires high reactivity at both polymer ends and efficient cyclization under high dilution conditions to prevent intermolecular reactions.…”

Section: Application Of M2rmentioning

confidence: 99%

Topology-transformable polymers: linear–branched polymer structural transformation via the mechanical linking of polymer chains

Takata

Aoki

2017

Polym J

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In this review article, we discuss the synthesis and dynamic nature of macromolecular systems that have mechanically linked polymer chains capable of undergoing a topology transformation driven by a rotaxane molecular switch. The rotaxane linking of polymer chains plays a crucial role in these systems. A linear polymer possessing a crown ether/sec-ammonium salt-type [1] rotaxane moiety at the axle chain terminal was prepared via the rotaxane linking of a single polymer chain. A linear-cyclic polymer topology transformation was achieved via the movement of the wheel component from one end to the other end of the axle component using the rotaxane macromolecular switch function. The successful synthesis of a macromolecular [2]rotaxane (M2R) possessing a single polymer axle and one crown ether wheel led to a variety of unique applications, such as the development of topology-transformable polymers and the synthesis of rotaxane crosslinked polymers (RCPs). The introduction of a polymer chain to the wheel component of M2R (rotaxane linking of two polymer chains) produced a rotaxane-linked AB block copolymer that transformed its topology from linear to branched. Furthermore, a rotaxane-linked three-component polymer and an ABC triblock copolymer were synthesized and transformed to the corresponding 3-arm star (co)polymers, and the transformation was confirmed by measuring the hydrodynamic volume change. The structural transformation of 4-arm and 6-arm star polymers was also accomplished using the dynamic mobility of a similar rotaxane. As a useful application, M2R-based vinylic crosslinkers (RCs) were prepared and applied to the synthesis of RCPs, whereby the addition of RCs into radical polymerization systems of vinyl monomers afforded polymers with excellent toughness by enhancing both of tradeoff properties that cannot be achieved using typical covalent crosslinkers.

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Topological polymer chemistry for designing multicyclic macromolecular architectures

Cited by 62 publications

References 55 publications

Crystallization of Cyclic Polymers

Crystallization of Cyclic Polymers

Synthesis and post-polymerization reaction of end-clickable stereoregular polymethacrylates via termination of stereospecific living anionic polymerization

Topology-transformable polymers: linear–branched polymer structural transformation via the mechanical linking of polymer chains

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