研究者詳細 - 金岡　鐘局

論文 - 金岡　鐘局

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Structure–property relationship of phenoxyimine ligands/metal chloride initiating systems for controlled cationic polymerizations of alkyl vinyl ethers 査読

Kigoshi S., Kanazawa A., Kanaoka S., Aoshima S.

Journal of Polymer Science, Part A: Polymer Chemistry 2019年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Polymer Science, Part A: Polymer Chemistry 参加形態：共同（副担当）

© 2019 Wiley Periodicals, Inc. The catalyst structure–property relationships of the phenoxyimine complexes in controlled cationic polymerization of vinyl ethers were investigated based on the Hammett correlation. The correlation analyses of a series of experiments using the phenoxyimine ligands/TiCl4 initiating systems indicated that the substituents on the N-aryl phenoxyimine ligands affected the polymerization rate and stereoselectivity. Importantly, a linear correlation was observed between the Hammett substituent constants and the polymerization rates, which indicates that the Lewis acidity of the complex is affected by the electron-withdrawing and -donating effects of the substituents. The tacticity of product polymers correlated to the Hammett substituent constants. Unlike the relationship with the polymerization rates, the σ– values, which account for the enhanced resonance effects, were more appropriate for the relationship with the tacticity than the normal σ values. In contrast, the polymerization behavior using o-substituted ligands exhibited a trend different from those using p- or m-substituted ligands. The structural change, which was caused by the rotation of the CN bonding, most likely triggered the acceleration effect in the case of the o-substituents. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019.

DOI： 10.1002/pola.29458

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Swelling Properties of Thermoresponsive/Hydrophilic Co-networks with Functional Crosslinked Domain Structures 招待査読国際誌

Shohei Ida*, Hironobu Kitanaka, Tatsuya Ishikawa, Shokyoku Kanaoka, Yoshitsugu Hirokawa

Polymer Chemistry 9 ( 13 ) 1701 - 1709 2018年4月

Precision Synthesis of Polylactide-Based Thermoresponsive Block Copolymers via Successive Living Cationic Polymerization of Vinyl Ether and Ring-Opening Polymerization of Lactide 査読

Seki Y., Kanazawa A., Kanaoka S., Fujiwara T., Aoshima S.

Macromolecules 51 ( 3 ) 825 - 835 2018年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules 参加形態：共同（副担当）

© 2018 American Chemical Society. A new class of polylactide (PLA)-based block copolymers with thermoresponsive poly(vinyl ether) [poly(VE)] were precisely synthesized via successive living cationic polymerization of VE and ring-opening polymerization of lactide (LA). The synthetic route starts with precise end-functionalization of poly(VE) by living cationic polymerization to produce a macroinitiator having a hydroxy group at the α- and/or -end for ring-opening polymerization of LA. End-functionalized polymers of 2-methoxyethyl VE (MOVE) with highly controlled structures were obtained by either an initiation or a termination method under optimized conditions. Subsequent ring-opening polymerization of LA from the hydroxy group of the macroinitiator yielded block copolymers with well-defined structures. The obtained block copolymers were demonstrated to exhibit a thermoresponsive solubility transition in water; this transition was induced by the thermosensitivity of the poly(MOVE) segments. The transition between micelle-like aggregates and phase separation was reversible with a shorter PLA chain, whereas irreversible precipitation was observed with a longer PLA segment. The permanent precipitation upon heating is most likely attributable to crystalline formation of the longer PLA segments. The solution and bulk properties of the block copolymers with enantiomeric PLA were also governed by stereocomplex formation between poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) segments.

DOI： 10.1021/acs.macromol.7b02329

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Synthesis of Highly Defined Graft Copolymers Using a Cyclic Acetal Moiety as a Two-Stage Latent Initiating Site for Successive Living Cationic Polymerization and Ring-Opening Anionic Polymerization 査読

Yokoyama N., Kanazawa A., Kanaoka S., Aoshima S.

Macromolecules 51 ( 3 ) 884 - 894 2018年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Macromolecules 参加形態：共同（副担当）

© 2018 American Chemical Society. The synthesis of well-defined graft copolymers with designed intervals between branches was achieved using cyclic acetal moieties as two-stage latent initiating sites. A cyclic acetal was shown to initiate the living cationic polymerization of vinyl ethers (VEs), yielding a polymer with a hydroxy group at the α-end derived from the cyclic acetal. The newly generated hydroxy group was able to efficiently induce the subsequent ring-opening anionic polymerization of l-lactide (LLA), and a diblock copolymer with a narrow molecular weight distribution (MWD) was obtained. For the synthesis of a graft copolymer, a five-membered cyclic acetal moiety was introduced at the Ï‰-chain ends of poly(VE)s, which was employed as the initiating site for the living cationic polymerization of VEs. Repeated polymerization and acetalization generated a macroinitiator with several hydroxy groups on the side chain of a poly(VE) backbone. Graft copolymers possessing branches with narrow MWDs and regular spaces between the branches were synthesized by the ring-opening polymerization of LLA using this macroinitiator.

DOI： 10.1021/acs.macromol.7b02622

Scopus

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Aggregation of cationic amphiphilic block and random copoly(vinyl ether)s with antimicrobial activity 査読

Oda Y., Yasuhara K., Kanaoka S., Sato T., Aoshima S., Kuroda K.

Polymers 10 ( 1 ) 2018年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Polymers

© 2018 by the authors. In this study, we investigated the aggregation behaviors of amphiphilic poly(vinyl ether)s with antimicrobial activity. We synthesized a di-block poly(vinyl ether), B3826, composed of cationic primary amine and hydrophobic isobutyl (iBu) side chains, which previously showed antimicrobial activity against Escherichia coli. B3826showed similar uptake behaviors as those for a hydrophobic fluorescent dye, 1,6-diphenyl-1,3,5-hexatriene, to counterpart polymers including homopolymer H44 and random copolymer R4025, indicating that the iBu block does not form strong hydrophobic domains. The cryo-TEM observations also indicated that the polymer aggregate of B3826appears to have low-density polymer chains without any defined microscopic structures. We speculate that B3826formed large aggregates by liquid-liquid separation due to the weak association of polymer chains. The fluorescence microscopy images showed that B3826bonds to E. coli cell surfaces, and these bacterial cells were stained by propidium iodide, indicating that the cell membranes were significantly damaged. The results suggest that block copolymers may provide a new platform to design and develop antimicrobial materials that can utilize assembled structures and properties.

DOI： 10.3390/polym10010093

Scopus

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Precision synthesis of degradable alternating copolymers of fluorine-containing vinyl ethers and conjugated aldehydes 査読

Matsumoto S., Kanazawa A., Kanaoka S., Aoshima S.

Kobunshi Ronbunshu 74 ( 6 ) 608 - 615 2017年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Kobunshi Ronbunshu 参加形態：共同（副担当）

© 2017, The Society of Polymer Science, Japan. Degradable alternating copolymers with distinctly fluorous characteristics were synthesized via controlled cationic copolymerization of perfluoroalkyl vinyl ethers (VEs) and conjugated aldehydes. Well-defined alternating copolymers were obtained using the EtSO3H/GaCl3 initiating system in the presence of 1,4-dioxane as an added base and 2,6-di-tert-butylpyridine as a proton trap in a fluorine solvent at -78°C. Various conjugated aldehydes and fluorine-containing VEs were also investigated for controlled alternating cationic copolymerization. The solubility of the obtained alternating copolymers improved compared to the fluorine-containing VE homopolymer. In particular, copolymers underwent upper critical solution temperature-type phase separation behavior in various solvents. In addition, polymer thin films of the alternating copolymers exhibited high water and oil repellency. All alternating copolymers were decomposed into small molecules under an acidic condition without residual oligomers in both solution and thin film state.

DOI： 10.1295/koron.2017-0032

Scopus

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Tandem Reaction of Cationic Copolymerization and Concertedly Induced Hetero-Diels–Alder Reaction Preparing Sequence-Regulated Polymers 査読国際誌

Suzuka Matsumoto, Arihiro Kanazawa, Shokyoku Kanaoka, Sadahito Aoshima

Journal of the American Chemical Society 139 ( 23 ) 7713 - 7716 2017年6月

Biphasic Synthesis of “Block” Copolymers and Star-Shaped Polymers via Monomer-Selective Cationic Copolymerization inOrganic/Fluorinated Solvents 査読

Mayuka Yamada, Tsuyoshi Nishikawa, Arihiro Kanazawa, Shokyoku Kanaoka, Sadahito Aoshima

Journal of Polymer Science, Part A: Polymer Chemistry 54 ( 17 ) 2656 - 2661 2016年9月

Cationic Polymerization of Vinyl Ethers with Alkyl or Ionic Side Groups in Ionic Liquids 査読国際誌

H. Yoshimitsu, A. Kanazawa, S. Kanaoka, S. Aoshima

Journal of Polymer Science Part A: Polymer Chemistry 54 ( 12 ) 1774 - 1784 2016年6月

Design of Blood-Compatible Interfaces with Poly(vinyl ether)s 査読国際誌

Y. Oda, C. Zhang, D. Kawaguchi, H. Matsuno, S. Kanaoka, S. Aoshima, K. Tanaka

Advanced Materials Interfaces 3 2016年5月

Shape-Switching Self-Assembly of New Diblock Copolymers with UCST-type and LCST-type Segments in Water 査読国際誌

H. Yoshimitsu, E. Korchagina, A. Kanazawa, S. Kanaoka, F. M. Winnik, S. Aoshima

Polymer Chemistry 7 ( 11 ) 2062 - 2068 2016年3月

Quantitative and Ultrafast Synthesis of Well-Defined Star-Shaped Poly(p-Methoxystyrene) via One-Pot Living Cationic Polymerization 査読国際誌

T. Yoshizaki, A. Kanazawa, S. Kanaoka, S. Aoshima

Macromolecules 49 ( 1 ) 71 - 79 2016年1月

Synthesis of Block or Graft Copolymers Containing Poly(Styrene Derivatives) Segments by Living Cationic Polymerization Using Acetal Moieties as Latent Initiating Sites 査読国際誌

N. Yokoyama, H. Yoshida, A. Kanazawa, S. Kanaoka, S. Aoshima

Polymer Chemistry 6 ( 35 ) 6316 - 6324 2015年9月

含フッ素セグメントをもつブロックコポリマーの精密合成および水/有機層間を往復可能な高分子ミセルの創製査読

山中悠司、金澤有紘、金岡鐘局、青島貞人

高分子論文集 72 ( 7 ) 480 - 485 2015年7月

ビニルエーテルとスチレン類を有する新規ブロックポリマーの精密合成および高感度温度応答性フィルムの創製査読

吉﨑友哉、金澤有紘、金岡鐘局、青島貞人

高分子論文集 72 ( 7 ) 486 - 490 2015年7月

Sequence-Controlled Degradable Polymers by Controlled Cationic Copolymerization of Vinyl Ethers and Aldehydes: Precise Placement of Cleavable Units at Predetermined Positions 査読国際誌

M. Kawamura, A. Kanazawa, S. Kanaoka, S. Aoshima

Polymer Chemistry 6 ( 22 ) 4102 - 4108 2015年6月

Controlled Radical Polymerization of Styrene with Magnetic Iron Oxides Prepared through Hydrothermal, Bioinspired, and Bacterial Processes 査読国際誌

A. Kanazawa, K. Satoh, S. Kanaoka, et al.

RSC Advances 5 ( 64 ) 51122 - 51129 2015年6月

Density Profiles of Well-Defined Poly(methyl 2-propenyl ether) (PMPE) near Water Interface 査読国際誌

Y. Oda, D. Kawaguchi, T. Hirata, N. L. Yamada, S. Kanaoka, S. Aoshima, K. Tanaka

Macromolecular Symposia 350 ( 1 ) 99 - 104 2015年4月

New Initiating Systems for Cationic Polymerization of Plant-Derived Monomers: GaCl₃/Alkylbenzene-Induced Controlled Cationic Polymerization of β-Pinene 査読国際誌

Y. Karasawa, M. Kimura, A. Kanazawa, S. Kanaoka, S. Aoshima

Polymer Journal 47 ( 2 ) 152 - 157 2015年2月

Dynamic-driven Surface Segregation of a Hydrophilic Component in Diblock Copolymer Films 査読国際誌

C. Zhang, Y. Oda, D. Kawaguchi, S. Kanaoka, S. Aoshima, K. Tanaka

Chemistry Letters 44 ( 2 ) 166 - 168 2015年2月

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