ESA-CF Synthesis of Linear and Cyclic Polymers Having Densely Appended Perylene Units and Topology Effects on Their Thin-Film Electron Mobility

Kimura, A.; Hasegawa, Tsukasa; Yamamoto, Takuya; Matsumoto, Hidetoshi; Tezuka, Yasuyuki

doi:10.1021/acs.macromol.6b01225

Cited by 15 publications

(8 citation statements)

References 44 publications

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“…Such differences in chemical and physical properties between cyclic and linear polymers have been attributed to the absence of polymer chain ends. Furthermore, the material − and biomedical properties , of cyclic and related polymer architectures have been widely investigated in recent years; these studies highlighted the exciting potential of cyclic polymers, not only for academic interest but also for practical applications.…”

Section: Introductionmentioning

confidence: 99%

Multicyclic Polymer Synthesis through Controlled/Living Cyclopolymerization of α,ω-Dinorbornenyl-Functionalized Macromonomers

et al. 2018

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A novel synthesis of multicyclic polymers that feature ultradense arrays of cyclic polymer units has been developed by exploiting the cyclopolymerization of α,ω-norbornenyl end-functionalized macromonomers mediated by the Grubbs thirdgeneration catalyst (G3). Owing to the living polymerization nature, the number of cyclic repeating units in these multicyclic polymers was controlled to be between 1 and approximately 70 by varying the initial macromonomer-to-G3 ratio. The ring size was also tuned by choosing the molecular weight of the macromonomer; in this way we successfully prepared multicyclic polymers that possess cyclic repeating units composed of up to about 500 atoms, which by far exceeds those prepared to date by cyclopolymerization. Specifically, cyclopolymerizations of α,ω-norbornenyl end-functionalized poly(L-lactide)s (PLLAs) proceeded homogeneously under highly dilute conditions (∼0.1 mM in CH 2 Cl 2 ) to give multicyclic polymers that feature cyclic PLLA repeating units on the polynorbornene backbone. The cyclic product architectures were confirmed not only by structural characterization based on NMR, MALDI-TOF MS, and SEC analyses but also by comparing their glass transition temperatures, viscosities, and hydrodynamic radii with their acyclic counterparts. The cyclopolymerization strategy was applicable to a variety of α,ω-norbornenyl end-functionalized macromonomers, such as poly(ε-caprolactone), poly(ethylene glycol) (PEG), poly(tetrahydrofuran), and PLLA-b-PEG-b-PLLA. The successful statistical and block cyclocopolymerizations of the PLLA and PEG macromonomers gave amphiphilic multicyclic copolymers.

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Section: Introductionmentioning

confidence: 99%

Multicyclic Polymer Synthesis through Controlled/Living Cyclopolymerization of α,ω-Dinorbornenyl-Functionalized Macromonomers

et al. 2018

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“…Cyclic or ring polymers represent an exciting class of topologically distinctive polymers. ,− As a result of “end-to-end” tethering and unusual conformation, cyclic polymers can exhibit bulk properties and behaviors considerably different from linear analogues of the same molecular weight (MW), e.g., T g , ,,− rheology, − and fragility, , among others. − Few experimental studies have investigated how confinement affects properties of cyclic polymer. ,− For example, Foster and co-workers studied free-surface dynamics of unentangled cyclic PS melts, finding slower surface fluctuations compared to linear analogues due to differences in bulk T g and that confinement effects are evident at larger film thickness than in films of the linear chain analogue . We observed an invariance of T g with confinement in supported films of low MW cyclic PS ( c -PS), in stark contrast to the major T g -confinement effect associated with linear PS. ,− , Because of its more limited conformational mobility, the cyclic topology strongly restricts polymer–substrate hydrogen-bonding interactions .…”

Section: Introductionmentioning

confidence: 99%

Suppression of the Fragility-Confinement Effect via Low Molecular Weight Cyclic or Ring Polymer Topology

Zhang¹,

Elupula

Grayson

et al. 2017

Macromolecules

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We used differential scanning calorimetry and spectroscopic ellipsometry to measure the molecular weight (MW) dependence of bulk fragility (m bulk) and spectroscopic ellipsometry to measure the thickness dependences of the glass transition temperature (T g) and fragility (m) in supported thin films of low MW cyclic or ring polymer. The effects of confinement on T g and m of thin polymer films are important in a range of advanced technology applications, including nanoimprinting. It has previously been shown that nanoconfined films of high MW linear polystyrene (PS) exhibit major T g- and m-confinement effects whereas films of low MW cyclic PS (c-PS) show at most a very weak T g-confinement effect. In the absence of chain ends, c-PS exhibits very weak T g,bulk– and m bulk–MW dependences compared to linear PS. Despite low MW c-PS having m bulk values similar to that of high MW linear PS, we found that low MW c-PS films show a very weak m-confinement effect because of a weak free-surface effect; e.g., m for a 27 nm thick film of 3.4 kg/mol c-PS is the same as m bulk within error. Overall, these results support a strong correlation between the susceptibility of fragility perturbation and the susceptibility of T g perturbation caused by MW reduction, chain topology, and/or confinement.

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“…Considerable attention has been payed to macromolecular architectures containing cyclic topologies [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22], where the progress in the synthetic methods for cyclic polymers including ring-closing and/or ring-expansion methods has greatly contributed to the field [23,24,25,26,27,28,29,30,31]. However, ring-expansion “vinyl” polymerization as a tool to generate cyclic polymers via a one-step vinyl polymerization is relatively unexplored, including those based on the nitroxide-mediated controlled radical polymerization (NMP) [32,33,34,35], reversible addition fragmentation chain transfer (RAFT) polymerization [36], living cationic polymerization [37,38,39,40], and others [41].…”

Section: Introductionmentioning

confidence: 99%

Ring-Expansion/Contraction Radical Crossover Reactions of Cyclic Alkoxyamines: A Mechanism for Ring Expansion-Controlled Radical Polymerization

et al. 2018

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Macrocyclic polymers present an important class of macromolecules, displaying the reduced radius of gyration or impossibility to entangle. A rare approach for their synthesis is the ring expansion-controlled radical “vinyl” polymerization, starting from a cyclic alkoxyamine. We here describe ring-expansion radical crossover reactions of cyclic alkoxyamines which run in parallel to chain-propagation reactions in the polymerization system. The radical crossover reactions extensively occurred at 105–125 °C, eventually producing high molecular weight polymers with multiple inherent dynamic covalent bonds (NOC bonds). A subsequent ring-contraction radical crossover reaction and the second ring-expansion radical crossover reaction are also described. The major products for the respective three stages were shown to possess cyclic morphologies by the molecular weight profiles and the residual ratios for the NOC bonds (φ in %). In particular, the high φ values ranging from ca. 80% to 98% were achieved for this cyclic alkoxyamine system. This result verifies the high availability of this system as a tool demonstrating the ring-expansion “vinyl” polymerization that allows them to produce macrocyclic polymers via a one-step vinyl polymerization.

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ESA-CF Synthesis of Linear and Cyclic Polymers Having Densely Appended Perylene Units and Topology Effects on Their Thin-Film Electron Mobility

Cited by 15 publications

References 44 publications

Multicyclic Polymer Synthesis through Controlled/Living Cyclopolymerization of α,ω-Dinorbornenyl-Functionalized Macromonomers

Multicyclic Polymer Synthesis through Controlled/Living Cyclopolymerization of α,ω-Dinorbornenyl-Functionalized Macromonomers

Suppression of the Fragility-Confinement Effect via Low Molecular Weight Cyclic or Ring Polymer Topology

Ring-Expansion/Contraction Radical Crossover Reactions of Cyclic Alkoxyamines: A Mechanism for Ring Expansion-Controlled Radical Polymerization

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