Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

(Diamine)Pd(0)(dichlone)/NaBPh₄ systems have been revealed to be effective initiators for diazoacetate polymerization, yielding moderately syndiotactic polymers in moderate yields.

DOI： 10.1039/d2py01548j

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

Dispersion polymerization stabilized with poly(acrylic acid) has been performed for decades to produce polymer particles whose surfaces are modified with pH-responsive poly(acrylic acid) moieties. To improve stabilizer efficiency, poly(acrylic acid) block copolymers, in which a poly(acrylic acid) chain is attached to the terminus of a polystyrene or PMMA chain, were used as stabilizers for the dispersion polymerization of styrene or MMA. Compared with the poly(acrylic acid) homopolymer, polystyrene-block-poly(acrylic acid) was found to improve the controllable ranges of particle size and the carboxylic-acid-group surface density of the resulting polystyrene particles. Furthermore, we also investigated the effect of heterogeneity between the polymer species of the particle core and the attached polystyrene or PMMA chains in the poly(acrylic acid) block copolymers. Finally, we also examined the applicability of polystyrene-block-poly(acrylic acid) as a stabilizer and surface modifier for the dispersion polymerization of various monomers.

DOI： 10.1016/j.polymer.2022.125265

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Three new N-arylmaleimide-based Pd(0) complexes [Pd(N-phenylmaleimide)2(2,5-norbornadiene) (1), Pd(N-2,6-difluorophenylmaleimide)2(2,5-norbornadiene) (2), and Pd(N-2,6-difluorophenylmaleimide)2(dibenzylideneacetone) (3)] were prepared and used as an initiator in conjunction with NaBPh4 [Pd(N-arylmaleimide)/NaBPh4 system] for polymerization of diazoacetates. The Pd(N-arylmaleimide)/NaBPh4 system polymerized a series of diazoacetates (ethyl, benzyl, and cyclohexyl diazoacetates) to yield polymers in moderate to good yield, particularly showing a high activity for cyclohexyl diazoacetate. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis and other experimental observations revealed the incorporation of one N-arylmaleimide molecule coordinated on the Pd center into the α-chain end of the polymers obtained with the initiating system, indicating that the initiating species of the polymerization was generated by insertion of N-arylmaleimide into a Pd–Ph linkage, which was first formed by the reaction of the Pd(0) complex with NaBPh4, and that the initiating system would enable syntheses of α-chain-end-functionalized poly(alkoxycarbonylmethylene)s.

DOI： 10.1021/acs.macromol.2c00508

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

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Other Link： https://web.opar.ehime-u.ac.jp/wp/wp-content/uploads/2021/04/J19-7_itoh.pdf

Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

<p>The reactivities of poly(alkoxycarbonylmethylene)s under basic conditions are described. The reactions of poly(ethoxycarbonylmethylene) (<bold>polyEDA’</bold>) and poly(benzyloxycarbonylmethylene) (<bold>polyBDA’</bold>) with a mixture of lithium diisopropylamide and trimethylsilyl chloride transformed a part of...</p>

DOI： 10.1039/d0py01486a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

A variety of benzyl ether-type dendron units were introduced as an ester substituent of diazoacetates, and their Pd-initiated polymerization behavior was investigated in detail. Because of the steric effect of the bulky dendron units, the monomers afforded polymers with narrow molecular weight distribution (MWD), and the polydispersity index became smaller with the increase of the bulkiness of the ester substituents. Narrow MWD polymers were also obtained by copolymerization of the dendron-containing monomers with ethyl diazoacetate bearing a sterically less bulky substituent and polymerization of dendron-containing monomers bearing 3,5-bis(alkoxycarbonyl)phenyl groups at its periphery. Deprotection of the alkoxycarbonyl groups of the latter polymerization products yielded dendronized polymers having multiple carboxy groups around their rigid main chains, whose pH-responsive behavior in aqueous media was significantly different from that of the corresponding vinyl polymers with the same side chains.

DOI： 10.1021/acs.macromol.0c01029

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

In this study, we developed azobenzene polymer particles showing several light-induced shape changes. Conventional azobenzene particles require exposure to polarized white or blue light on a substrate for shape elongation. First, the dispersion polymerization of 6-[4-(4′-methoxyphenylazo)phenoxy]hexyl methacrylate afforded unique oval or short cylindrical shapes with controlled sizes and narrow size distributions. Then, polarized optical microscopic observations and wide-angle X-ray diffraction measurements suggest that the azobenzene moiety formed a uniaxially orientated smectic-layered structure in the particles. Differential scanning calorimetric measurements indicated that the packing structures and particle shapes were closely related to each other. Finally, the particle shape was altered by the trans–cis photoisomerization of azobenzene accompanied by the deformation of the azobenzene packing structure. Interestingly, their shape anisotropy was increased by ultraviolet and white-light irradiation. The particle shape was changed in a dispersed medium and on a substrate by unpolarized light. Consequently, the combination of a light source and site varied the light-induced shape changes of the azobenzene particles.

DOI： 10.1021/acsapm.0c00475

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

In the polymerization of diazoacetates initiated by pi-allylPd-based initiating systems, the effects of solvents, additives, and pi-allyl ligand structures on the polymerization behavior were investigated. As a result, the polymerization in the presence of pyridine or its derivatives as an additive was found to afford a polymer with relatively narrow molecular weight distribution compared to that with pi-allylPdCl alone. Furthermore, we have demonstrated that Pd complexes with pi-allyl ligands with a variety of substituents are capable of polymerizing diazoacetates in a similar manner to the parent unsubstituted pi-allylPdCl, and the tacticity of the resulting polymers is affected by the structure of the pi-allyl ligands.

DOI： 10.1039/c9py01654f

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

© 2019, The Society of Polymer Science, Japan. The synthesis and characterization of organic-inorganic thermoresponsive poly(substituted methylene)s are described. Diazoacetates with oligo(ethylene glycol)-substituted cyclotriphosphazenes were synthesized, and the obtained products were employed as monomers for Pd-initiated polymerization to produce carbon–carbon main chain polymers bearing an oligo(ethylene glycol)-substituted cyclotriphosphazene on every main chain carbon atom. The resulting polymers with densely accumulated oligo(ethylene glycol) units around the polymer main chain showed lower critical solution temperature-type phase separation in an aqueous medium.

DOI： 10.1038/s41428-019-0247-7

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Other Link： http://www.nature.com/articles/s41428-019-0247-7

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

© 2020 American Chemical Society. The original synthetic strategy for a new type of poly(arylene vinylene) (PAV) is presented, where the C-C-bond-forming coupling of bis(alkoxycarbonyldiazomethyl)aromatic compounds is utilized as propagation. The strategy is unique in that the resulting PAVs have an alkoxycarbonyl group as an electron-withdrawing substituent on each vinylene carbon atom in the polymer main chain. Among the transition-metal catalysts examined in this study, RuCl(cod)Cp∗ (cod = 1,5-cyclooctadiene, Cp∗ = pentamethylcyclopentadienyl) is the most efficient, affording PAVs from a series of bis(alkoxycarbonyldiazomethyl)aromatic compounds with a high trans-C-C-forming selectivity of up to 90%. A PAV sample with a fluorenylene framework as an arylene moiety prepared by the Ru catalyst exhibited a hole mobility of 4 × 10-6 cm2 V-1 s-1.

DOI： 10.1021/acsomega.9b03408

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.9b00857

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

DOI： 10.1021/acs.macromol.9b00653

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

This study reported the control of molecular weights of functional polymer chains attached to the surfaces of the narrowly distributed environmentally responsive particles obtained from a single step process. As a proof-of-concept, a pH-responsive poly(l-glutamic acid) (PLGA) macromonomer with a degree of polymerization (n) of 50 or 260 was prepared by the ring-opening polymerization of γ-benzyl-l-glutamate N-carboxy anhydride; this was performed using 4-vinylbenzylamine and was followed by hydrolysis. The pH-responsive PLGA macromonomer was further used as a stabilizer for the dispersion polymerization of styrene. Each macromonomer stabilized the dispersion polymerization, affording narrowly distributed polystyrene particles exhibiting pH-responsive aggregation or dispersion behavior, thereby indicating the graft of PLGA chains on the particle surface. Large particles with a low surface density were obtained using PLGA260. The particle sizes and surface glutamic acid densities were tunable over 0.8–2.0 μm and 0.4–1.8 unit/nm2, respectively, while maintaining narrow size distributions.

DOI： 10.1016/j.polymer.2018.10.040

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.7b01964

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.7b01994

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Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

A novel poly(l-lysine) macromonomer was successfully prepared via a click reaction between vinyl benzyl azide and propargyl-terminated poly(l-lysine), and it was used as a functional stabilizer for the dispersion polymerization of styrene; narrowly distributed polystyrene particles were produced as a result, onto which cationic poly(l-lysine) chains were grafted. The resulting particles exhibited a pH-responsive dispersion behavior in aqueous solutions due to the properties of the poly(l-lysine) chains at the particle surface. It was found that the particle size and the surface density of the resultant particles could be varied by tuning the concentrations of the macromonomer, styrene, and initiator used in the initial solution of the dispersion polymerization. The poly(l-lysine) macromonomer was also found to be effective when used as a stabilizer for the dispersion polymerization of both methyl methacrylate and a styrene/acrylonitrile mixture.

DOI： 10.1016/j.polymer.2017.04.077

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

<p>The initiating ability of a new system, amidinate/Pd, for the polymerization of diazoacetates is described.</p>

DOI： 10.1039/c7py00816c

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Cyclopolymerization of bis(diazocarbonyl) compounds is described for the first time. By choosing appropriate reaction conditions and monomer structures, the cyclopolymerization of bis(diazoacetate)s efficiently proceeded to give carbon-carbon main chain cyclopolymers with well-defined structures, as confirmed by MALDI-TOF-MS analyses. The products are a new kind of cyclopolymer with respect to polymer structure: there exists no free methylene in the sp(3)-carbon-based polymer backbone in contrast to conventional cyclopolymers prepared from divinyl compounds, which inevitably have free methylenes in and between cyclic units in their polymer backbones. The resulting cyclopolymers with closely aligned cyclic units along the polymer backbone showed a much higher glass transition temperature compared to the corresponding polymers without cyclized repeating units.

DOI： 10.1021/acs.macromol.6b01809

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

A new carbon-carbon main chain polymer with N-phenyl-2,6-dimethoxybenzamide on its each main chain carbon atom is prepared by Pd-initiated polymerization of diazoacetate containing the benzamide group, and the Li ion conductivity of the polymer doped with lithium bis(trifluoromethylsulfonyl)imide is evaluated along with its vinyl polymer counterparts with the same benzamide substituent. Although the expected high ion conductivity at low temperatures derived from a unique ion transport mechanism based on the bond rotation in the benzamide moiety reported in a literature is not observed, it is revealed that the dense packing of the benzamide group along the polymer main chain results in the enhanced ion conductivity. In addition, investigation of the correlation between ion conductivity and glass transition temperature of these solid polymer electrolytes (SPEs) reveals that other ion transport mechanism would operate in the benzamide containing SPEs than that derived from segmental motion of polymer chains observed in PEO-based SPEs. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.ssi.2016.05.001

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

Pd-initiated polymerization and oligomerization of diazo compounds containing a dialkoxyphosphinyl group are described. Polymerization of 2-dialkoxyphosphinylethyl diazoacetates with pi-allylPdCl-based initiating systems afforded C-C main chain polymers bearing phosphonate on each main chain carbon atom. The quantitative transformation of the side chain phosphonate to phosphonic acid resulted in the formation of water soluble polymers having the acid groups accumulated around their main chains, although the carbonyl ester linkage in the side chain was cleaved via intramolecular acid-assisted hydrolysis in water at 80 degrees C. Pd-initiated oligomerization of diethyl diazomethylphosphonate yielded an oligomeric product bearing diethoxyphosphiny groups directly attached to its main chain carbons, with unexpected incorporation of azo group in the main chain framework. Hydrolysis of the phosphonate of the oligomer afforded a water-soluble product, which was revealed to show higher proton conductivity than poly(vinylphosphonic acid) under certain conditions. (C) 2016 Wiley Periodicals, Inc.

DOI： 10.1002/pola.28030

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Other Link： http://orcid.org/0000-0001-8579-939X

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

A novel macromonomer composed of poly(α-l-glutamic acid) was used as a stabilizer for dispersion polymerization of styrene in DMF–water medium with AIBN initiator, giving narrowly-distributed functional polystyrene particles on which the poly(α-l-glutamic acid) was grafted. The resultant particles had 0.54–2.12 μm in size and 0.2–2.6 residue/nm2 in surface density and showed a pH-responsive colloidal behavior associated with a helix–coil transformation of the surface poly(α-l-glutamic acid). Not only the particle size but also the surface density were controlled with macromonomer concentration, macromonomer length, DMF composition, and styrene concentration, while no consistent trend for AIBN concentration was observed. A gel-permeation-chromatography curve of the particles was separated into three components. We tentatively identify the origin of each component and propose a possibility that unstable particles, which were generated even after the growing particles were stabilized, took an important role in particle growth and size distribution of the resultant particles.

DOI： 10.1016/j.polymer.2015.06.022

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：WILEY-V C H VERLAG GMBH  

Pd-initiated polymerization of alkyl diazoacetates as an effective methodology to prepare carbon-carbon (CC) main chain polymers bearing a substituent on every main chain carbon is described. (NHC)Pd/borate (NHC=N-heterocyclic carbene) systems are efficient at affording high M-n polymers. pi-AllylPdCl-based systems can initiate the polymerization with the number of polymer chain per Pd ratios over 1.0 because of occurrence of chain transfer, capable of affording relatively low M-n polymers in high yield. Initiation and termination mechanisms have been proposed for the latter initiating systems, based on the detailed MALDI-TOF-MS analyses of the low M-n products.

DOI： 10.1002/masy.201400007

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

We describe the polymerization of a variety of diazocarbonyl compounds initiated with Pd complexes. Relatively low molecular weight polymers (M-n = ca. 2000) were obtained by the polymerization of diazoacetates, diazoketones, and diazoacetamides initiated with PdCl2. On the other hand, the polymerization of diazoacetates by (NHC)Pd/borate and pi-allyl-PdCl-based systems can afford high molecular weight polymers (M-n &gt; 10000). Chain-end structure analyses by using MALDI-TOF-MS was used to elucidate initiation and termination mechanisms for the pi-allyl-PdCl-based systems. Polymerization of hydroxy-containing diazoacetates resulted in the formation of unique polymers with densely accumulated hydroxy groups around their C-C main chains.

DOI： 10.1295/koron.2014-0100

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Synthesis and characterization of polymers with densely-grafted oligo(ethylene glycol)s (OEGs) are described. Polymerization of OEG-containing diazoacetates with (eta(3)-C3H5)PdCl-based initiating systems afforded C-C main chain polymers bearing OEGs on each main chain carbon atom. The polymers with a short OEG side chain showed a lower critical solution temperature-type phase separation in an aqueous medium; the transition temperatures were higher than those of the corresponding vinyl polymers with the same oxyethylene chain length. In addition, the Li-ion conductivity was examined to reveal that the polymers with densely-grafted OEGs showed higher values than the corresponding vinyl polymers, despite the fact that no significant difference in the glass transition temperature was observed between the two types of polymers.

DOI： 10.1039/c5py01378j

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Polymerization of cyclophosphazene-containing diazoacetates was carried out using a (eta(3)-C3H5) PdCl-based initiating system to produce sp(3)-sp(3) carbon-carbon main chain polymers bearing a cyclophosphazene-containing ester group on every main chain carbon atom. The obtained polymers had very narrow molecular weight distributions in contrast to the case of other alkyl or aryl diazoacetates reported previously, suggesting that the polymerization of cyclophosphazene-containing diazoacetates proceeded in a controlled manner without apparent side reactions, which was confirmed by MALDI-TOF-MS analysis. In addition, block copolymers with a well-defined structure were successfully synthesized. This is the first report on controlled polymerization of diazoacetates to afford narrow molecular weight distribution polymers. Furthermore, thermogravimetric analysis was conducted to reveal that the resulting polymers had a higher thermal stability compared to the vinyl polymer counterparts.

DOI： 10.1039/c5py00532a

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

A block copolymer composed of polystyrene and poly(α-l-lysine hydrobromide) (PLL) segments was used as a stabilizer for dispersion polymerization of styrene in water–methanol medium to give narrowly-distributed polystyrene particles in the size range from 0.36 to 1.09 μm, on which the PLL segment was grafted with a surface density of 0.2–3.4 l-lysine residue/nm2. We investigated effects of polymerization time, stabilizer concentration, segmental composition of the block copolymer, and composition of the medium on surface structure and particle size of the affording particles. Interestingly, we obtained an experimental evidence that the surface density of the PLL clearly depends on structural parameters of the stabilizer and various polymerization conditions. Based on the dependence, it was possible to control the surface density of the narrowly-distributed particles within the range between the minimum and the maximum density limits of the graft chain by changing the structure of the stabilizer and polymerization conditions. Conformation of the PLL, which underwent a helix–coil transformation with an increase in water composition of the medium, had a strong effect on the surface structure, the size, and property of the resulting particles. Further modification of the particle surface was possible by utilizing the amino groups in the PLL graft.

DOI： 10.1016/j.polymer.2014.06.069

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Two types of polymerization of hydroxy-containing diazoacetates are described. The polymerization of hydroxy-containing diazoacetates using palladium complexes proceeded successfully under chain-growth mechanism even without a protecting group to give C-C main chain polymers bearing a hydroxy-containing ester substituent on each carbon of the backbone. The resulting polymers had a slightly branched structure due to chain transfer reaction with the hydroxy groups, while the polymers obtained by polymerization of silyl-protected diazoacetates and subsequent deprotection had a completely linear structure. The hydroxy-containing polymers with an appropriate hydrophilic/hydrophobic balance showed a lower critical solution temperature-type phase separation in an aqueous medium. On the other hand, the polymerization of hydroxy-containing diazoacetates using InCl3 as a catalyst proceeded under step-growth mechanism to give oligomers having a distinct repeating unit (ester-ether), where a new ether bond was generated through O-H insertion reaction of diazocarbonyl groups into hydroxy groups.

DOI： 10.1021/ma500783b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A variety of aliphatic- and aromatic-type unsaturated polyesters (UPs) were prepared by transition-metal-catalyzed single-component polycondensation of bis(diazoacetate)s under a mild condition. With the second-generation Grubbs catalyst, the polycondensation proceeded exclusively through an intermolecular highly cis-selective C=C forming coupling of diazo-bearing carbons with N-2 release, giving well-defined UPs. The cis-C=Cs of the resulting polymers could be isomerized quantitatively into trans-C=Cs with a catalytic amount of diethylamine. Additionally, other metal complexes, the first-generation Grubbs catalyst, rhodium(II) acetate, and copper(II) acetylacetonate, also produced UPs from the bis(diazoacetate)s, with lower stereoselectivities, although an unexpected carbene oligomerization of the monomers partially occurred along with the C=C bond-forming coupling.

DOI： 10.1021/ma401047x

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

The radical copolymerization of alkyl 2-norbornene-2-carboxylates, 1a-c, with alkyl (meth)acrylates, to produce copolymers with norbornane in the main chain, is described here. gamma-Butyrolactone-and hydroxy group-containing norbornene-based monomers (1b and 1c, respectively) were freshly synthesized, and their radical copolymerization behavior with n-butyl acrylate was examined. Methyl 2-norbornene-2-carboxylate, 1a, and the new monomers, 1b and 1c, were employed as comonomers for radical terpolymerization with lactone-and adamantane-containing (meth) acrylates to produce copolymers that could be applied as new, more chemically robust 193-nm photoresist materials. The dissolution rate of the spin-coated copolymer films after exposure to a photoacid generator, a significant characteristic in the photoresist application, was measured for various exposure doses of 193-nm ArF laser light under standard conditions in an aqueous alkaline solution.

DOI： 10.1038/pj.2012.180

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Radical copolymerization behavior of alkyl cyclobutenecarboxylate-derivatives 4-6 and related norbornene-derived compounds 79 is described. A variety of alkyl cyclobutenecarboxylates fused with cycloaliphatic framework (46) were prepared by [2 + 2] cycloaddition of five, six, and eight-membered cycloolefins with alkyl propiolates [alkyl = Me, 2-hydroxyethyl, and 3--butyrolactonyl (-BL)]. The fused cyclobutenecarboxylates 46 were radically copolymerized with n-butyl acrylate (nBA) to afford random copolymers, and terpolymerized with alkyl methacrylates with bulky ester groups [alkyl = -BL and 3-(3-methyladamantyl)]. The cyclobutane-containing bicyclic framework incorporated in the resulting polymer backbone contributes to raising Tg of resulting copolymers. Similar results were obtained when a mixture of related norbornene-derived compounds were used as monomers with an apparently enhanced Tg-raising effect in the copolymerization with nBA. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 27162724

DOI： 10.1002/pola.26668

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

DOI： 10.1002/pola.26480

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Other Link： http://orcid.org/0000-0001-8579-939X

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

A block copolymer (PS-b-poly(l-Glu)) composed of polystyrene and poly(l-glutamic acid) was used as a stabilizer for dispersion polymerization of styrene. When dispersion polymerization of styrene was conducted at 70 °C in 80% dimethylformamide–water with 0.5 wt% PS-b-poly(l-Glu), spherical polystyrene particles with Dn = 0.72 μm and narrow size distribution were obtained. Whereas AIBN concentration did not have any effects on particle size, molecular weight of the polystyrene particles was strongly dependent on the initiator concentration. As concentration of the PS-b-poly(l-Glu) increased from 0.2 to 1.0 wt%, particle size decreased from Dn = 0.91 to 0.69 μm with keeping surface area occupied by one poly(l-glutamic acid) chain about S = 50 nm2. On the other hand, an increase in initial concentration of styrene from 2 to 20 wt% caused an increase in particle size from Dn = 0.48 to 1.36 μm and a decrease in surface area per poly(l-glutamic acid) block from S = 91 to 45 nm2. Colloidal stability of the polystyrene particles in aqueous solution was responsive to pH due to the surface-grafted poly(l-glutamic acid). For dispersion polymerization of styrene, the PS-b-poly(l-Glu) functions as both a stabilizer and a surface modifier.

DOI： 10.1016/j.jcis.2012.08.040

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Polymerization of ethyl and benzyl diazoacetates (EDA and BDA) initiated with pi-allylPdCl-based systems [pi-allylPdCl/NaBPh4, pi-allylPdCl/NaBAr4F (Ar-F = 3,5-{CF3}(2)C6H3), and pi-allylPdCl] is described. Initiation efficiencies of the pi-allylPdCl-based systems are much higher than those of the previously reported (NHC)Pd/borate (NHC = N-heterocydic carbene) systems, and the new systems are capable of polymerizing the alkyl diazoacetates at low temperatures (0 similar to -20 degrees C), where the (NHC)Pd/borate systems cannot initiate the polymerization. MALDI-TOF-MS analyses of the polymers obtained from EDA provide information for the chain-end structures of the polymers, based on which initiation and termination mechanisms are proposed. Interestingly, EDA polymerization by the pi-allylPdCl-based systems in the presence of alcohols (EtOH, nPrOH, and nBuOH) or water was found to afford RO- or HO-initiated polymers as major products, as confirmed by MALDI-TOF-MS analyses.

DOI： 10.1021/ma3013527

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

The helix–coil transformations of block copolymers composed of poly(γ-benzyl-L-glutamate) (PBLG) and polystyrene (PS), in which PS was attached to either the N terminus (PBLGn-N-PSm) or the C terminus (PSn-C-PBLGm) of PBLG, were investigated in trifluoroacetic acid (TFA)–chloroform mixtures with TFA concentrations in the range of 0.7–10 vol%. The helical content (fH) estimated from 1H nuclear magnetic resonance measurements indicated that the PBLG segment in PBLG55-N-PS160 underwent a gradual helix–coil transformation from fH=1 to fH=0.75 over the range of 3.6–5.7 vol% TFA and then a drastic transformation to fH=0 at 9.5 vol% TFA, in a manner similar to that of the PBLG55 homopolymer. In PS120-C-PBLG55, the helical deformation of the PBLG segment was observed by adding a very small amount of TFA (0.7–3.6 vol%), followed by gradual and drastic transformations at higher TFA concentrations. The results indicate that the conformational stability of the C terminus in a PBLG chain differs from that of the N terminus. Transformations of PBLG/PS block copolymers with various molecular weights and compositions were also studied.

DOI： 10.1038/pj.2011.113

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Other Link： http://www.nature.com/articles/pj2011113

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

New types of poly(ester ether ketone)s 3 and 8 were prepared by three-component polycondensation of bis(diazoketone) 1 with a variety of dicarboxylic acids 2 and THF or THP catalyzed by Rh(2)(OAc)(4). THF was ring-opened and incorporated into almost every carboxyl O-H of 2 via simultaneous insertion together with a diazocarbonyl-derived carbene, resulting in the formation of a unique poly(ester ether ketone) framework. On the other hand, when THP was used as a cyclic ether, insertion of carbene alone into the carboxyl O-H (normal insertion) competes with the simultaneous insertion of THP and carbene, and the ratio of the two modes of insertion depends on the kind of 2 employed. The mode and selectivity of the propagation were confirmed by conducting Rh-catalyzed model reactions of diazoacetophenone 4 with 4-tert-butylbenzoic acid 5 in THF and THP.

DOI： 10.1021/ma201037p

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

(NHC)Pd/borate initiating systems (NHC = N-heterocyclic carbene) were applied for polymerization of alkyl diazoacetates with a variety of ester groups. The monomers with n-hexyl, cyclohexyl, benzyl, and cholesteryl group as an ester group were transformed into the corresponding poly(alkoxycarbonylmethylene)s with M-n &gt; 10 000. On the other hand, the polymerization of 1-adamantyl diazoacetate afforded low-M-n polymers (M-n &lt; 4000), probably because of steric reasons. Copolymerization of a few comonomer combinations also proceeded successfully to give copolymers with M-n &gt; 20 000.

DOI： 10.1021/ma200064b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Thermally induced polymerization of diazoketones, (E)-1-diazo-3-nonen-2-one 1 and (E)-1-diazo-4-phenyl-3-buten-2-one 2, is described. Heating 1 and 2 in a solvent at 60-100 degrees C afforded polymers, where all the main chain carbons bear acyl groups derived from the monomers and the main chain contains ca. 25-35 mol% of azo group. Molecular weight of the resulting polymers increased up to M(n) = 8,400 by the addition of benzoquinone to the reaction mixtures. The polymerization was supposed to proceed via radical propagating chain end and copolymerization of 1 with styrene gave copolymers (M(n) = 11,000-15,000) having acylmethylene, azo group, and repeating unit from styrene in their main chains.

DOI： 10.1007/s00289-010-0254-5

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Radical copolymerization of di(isobutoxy)methylvinylsilane 1 and di(isobutoxy)phenylvinylsilane 2 with methyl methacrylate (MMA) and n-butyl acrylate (n-BA) was carried out, and the oxidative cleavage of Si-C bonds in the resulting copolymers was examined to prepare copolymers having repeating units of vinyl alcohol (VA). Although the incorporation of 1 and 2 in the copolymerization of these alkoxyvinylsilanes with MMA was not so effective (1 or 2 content &lt; 18 mol%), MCPBA-induced oxidative transformation of a poly(2-co-MMA) with 9.0 mol% of 2 content proceeded efficiently, giving a poly[(vinyl alcohol)-co-MMA]. On the other hand, whereas poly(1 or 2-co-n-BA)s with relatively higher 1 or 2 contents (up to 45 mol%) can be prepared by the radical copolymerization of 1 or 2 with n-BA, oxidation of the copolymers afforded insoluble products.

DOI： 10.1007/s00289-009-0190-4

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A series of new polyetherketones was prepared by Rh-catalyzed polycondensation of bis(diazocarbonyl) compounds 1a-c with aromatic diols 2A-C in cyclic ethers (THF, THP, and 1,4-dioxane). In addition to the expected insertion of diazo-bearing carbon of I a c into O-H of 2A-C releasing N(2), unexpected incorporation of the ring-opened cyclic ethers between the diazo-bearing carbon of I a c and phenolic oxygen of 2A-C occurred, providing the polymer main chains with additional oxyalkylene units. The extent of-cyclic ether incorporation relative to the expected insertion depended on the kind of the cyclic ether: THF, 95-98%; THP, 26-32%; 1,4-dioxane, 11-21%. Polyetherketones with a variety of main chain structures can be prepared by the new polycondensation.

DOI： 10.1021/ma100494a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Radical copolymerization behavior of methyl 2-norbornene-2-carboxylate 1 and 2-phenyl-2-norbornene 2 was investigated. Radical copolymerization of 1 and 2 with styrene, alkyl acrylate, and methyl methacrylate in a variety of monomer combinations afforded copolymers, whose main chains consisted of norbornane framework. Relative monomer reactivity ratios for the copolymerization of 1 and 2 with n-butyl acrylate (n-BA) were determined by the Fineman-Ross method. Temperature-modulated DSC analysis for poly(l or 2-co-n-BA)s revealed remarkable T(g)-raising effect of incorporation of norbornane framework into the polymer main chain, compared to that effect of styrene repeating unit. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2009.12.008

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The Pd(O) complexes with N-heterocyclic carbene (NHC) ligand [(NHC)Pd] in conjunction with tetraarylborate [(NHC)Pd borate systems] which are capable of transforming ethyldiazoacetate (EDA) into poly(ethoxycarbonylmethylene)s M n &gt; 20000 has been reported. The crude product obtained after the removal of volatiles from the reaction mixture was purified by using preparative recycling GPC to give a colorless solid. The complexity of the MS charts indicates the non-uniformity of the (NHC) Pd borate system with respect to the initiation and termination, thus, leading to the aforementioned low controllability of the polymerization with respect to the molecular weight of products. The generality of the polymerization of diazocarbonyl compounds as a practical method for polymer synthesis is also reported.

DOI： 10.1021/ma901857s

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

The effects of polystyrene-b-poly(aminomethyl styrene) (PSn-b-PAMSm) stabilizers on the particle size () and size distribution (PSD) in dispersion polymerization of styrene were investigated. The block copolymers, PSn-b-PAMSm, were prepared as follows: (i) atom transfer radical polymerization (ATRP) of styrene (PS-Br), (ii) ATRP of vinylbenzylphthalimide with the PS-Br (PS-b-PVBP), and (iii) treatment of the PS-b-PVBP with hydrazine. When the dispersion polymerization of styrene proceeded at 60 °C in ethanol with PS19-b-PAMS130 stabilizer, spherical polystyrene particles with (PSD = 1.01) were obtained. The particle size was strongly affected by the copolymer composition. With an increase in PAMS block length from to 100 in PS17-b-PAMSm, particle diameter became smaller from 1.55 to 0.91 μm. On the other hand, an increase in the length from to 82 in PS34-b-PAMSms caused an increase in particle size from 0.35 to 0.70 μm. Titration of the particles suggests that 14–81% of stabilizers used in the polymerization system were attached on the polystyrene particle surfaces, depending on the composition of the block copolymers. Thus, for the dispersion polymerization of styrene, PSn-b-PAMSm block copolymers have both functions as a stabilizer during polymerization and surface-modification sites of polystyrene particles.

DOI： 10.1016/j.jcis.2008.10.052

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Pd-mediated copolymerization of bifunctional diazocarbonyl compounds, 1,1&apos;-bis(diazoacetyl)ferrocene 2, 4.4&apos;-bis(diazoacetyl)biphenyl 5, and bis(4-diazoacetylplienyl)dimethylsilane 6, with monofunctional diazoketones, (E)-1-diazo-3-nonen-2one 3 and (E)-1-diazo-4-phenyl-3-buten-2-one 4, and ethyl diazoacetate 7 was examined in order to prepare a new type of crosslinked polymer. Although copolymerization of 2 with 3 and 4 proceeded in the presence Of PcCl(2)(MeCN)(2), the products were soluble in CHCl(3) and their M(n)s were rather low irrespective of the feed ratio of the comonomers, probably because Of the occurrence of intramolecular cyclization of two diazoacetyl groups in 2. On the other hand, copolymerization of 5 and 6 with 3, 4, and 7 with relatively high feed ratios of the bifunctional monomers afforded products insoluble in CHCl(3), which suggested the formation of crosslinked polymers. In addition, Pd-mediated (co)polymerization of monofunctional diazoacetylferrocene 1, monofunctional counterpart to 2, was examined, resulting in the formation of a new type of ferrocene-containing polymer.

DOI： 10.1295/polymj.PJ2009065R

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

Copolycondensation of alpha,alpha-dibromotoluene (1) with alpha,alpha'-dibromo-p-xylylene (2) was found to proceed in the presence of excess Mg via nucleophilic substitution of in situ generated Grignard reagents to Br-bearing benzylic carbons. The use of dichlorodimethylsilane (3) and 1,6-dibromohexane (4) as a comonomer in the ternary copolycondensation with 1 and 2 was effective to give higher molecular weight polymers by improving their solubility. In the series of the copolycondensation, the copolymer with the highest M-n of 8480 was obtained in a 41% yield by the reaction of a feed ratio of [1]:[2]:[4] = 1:1:1 in THF at room temperature.

DOI： 10.1007/s00289-007-0858-6

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Palladium-mediated polymerization of cyclic diazoketones was investigated. Although cyclic diazoketones 1a,b derived from cyclohexanone and 1-tetralone did not homopolymerize, they can be used as a comonomer for copolymerization with polymerizable acyclic diazoketones. On the other hand, an alpha,beta-unsaturated cyclic diazoketone 2a prepared from 2-cyclohexen-1-one polymerized to give a polymer poly2a' with M-n = 1400 in a 23.8% yield. Addition of some nucleophiles to C=C bond in poly2a' was carried out. Copolymerization of 2a and its dimethyl-substituted analogues 2b,c with acyclic diazoketones was also investigated. (C) 2008 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22504

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Radical (co)polymerization behavior of alkoxyvinylsdanes [tri(isobutoxy)vinylsilane 1, triethoxyvinylsilane 2, di(isobutoxy)-methylvinyisilane 3, di(isobutoxy)phenylvinyl si lane 4, diethoxymethylvinylsilane 5, and diethoxyphenylvinylsilane 6] was systematically investigated. Homopolymerization and copolymerization with styrene of these alkoxyvinylsilanes were performed under various conditions in order to find appropriate initiating systems for the radical polymerizations. Transformation of some of the copolymers into poly[(vinyl alcohol)-co-styrene]s was examined via oxidative cleavage of the Si-C bonds in the alkoxyvinylsilane repeating units.

DOI： 10.1295/polymj.PJ2008113

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Palladium-mediated polymerization of diazoacetamides bearing various substituents 1-4 is described. Homopolymerization of monomers with n-hexyl or 4-n-octylphenyl group on the nitrogen afforded polymers [poly(N-substituted carbamoylmethylene)], whose all the main chain carbons have N-substituted carbamoly groups. Elemental analysis of the products indicated incorporation of azo group in the main chain. Copolymerization of diazoacetamides 1-4 with a diazoketone. (E)-1-diazo-4-phenyl-3-buten-2-one 5, proceeded efficiently, giving poly(substituted methylene)s with a variety of N-substituted carbamoyl groups in their side chains.

DOI： 10.1295/polymj.PJ2008145

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Polymerization of diazoketones mediated by organoaluminum compounds was investigated. Trialkylaluminum R3Al (R = iBu, Et, Me) and diisobutylaluminum hydride (DIBAL) polymerized (E)-1-diazo-3-nonen-2-one (1) to give polymers with M. = 2000-3500, which contained nearly 33 mol % of azo group (-N=N-) along with the dominant acylmethylene unit in the main chain. On the other hand, when (E)-1-diazo4-phenyl-3-buten-2-one (2) was used as a monomer for the organoaluminum-mediated polymerization, the resulting polymers had ethylidene (-CH[CH3]-) units in the main chain along with acylmethylene and azo group, as a result of reductive cleavage of the acyl group during the polymerization. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22266

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Radical copolymerization of alkyl 2-norbornene-2-carboxylates (alkyl = Me 1a, nBu 1b) with alkyl acrylates (alkyl = ethyl, methyl, and n-butyl) was investigated. Copolymerization of 1a,b with the alkyl acrylates initiated by 1,1'-azobis (cyclohexane-l-carbonitrile) at 85 degrees C proceeded to give random copolymers, although the homopolymerization of 1a,b did not proceed efficiently under the same conditions. Typically, bulk copolymerization of la with ethyl acrylate in a feed ratio of 1:3 ([1a]:[EA]) afforded a copolymer with Mn = 33,300 containing 19.4 mol % of 1a unit in the composition. An increase of T-g derived from the incorporation of the rigid norbornane framework was observed, although the extent of the temperature rise was rather moderate. The ternary radical copolymerization of 1a,b/alkyl acrylate/N-phenylmaleimide proceeded to give copolymers with the three repeating units in the main chain. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22197

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Temperature dependences of conformations of poly(β-phenethyl-L-aspartate) (PA) in block copolymer systems, in which polystyrene (PS) was attached to either N-terminus (PAn-N-PSm) or C-terminus (PSn-C-PAm) of the PA, respectively, were investigated in 1,1,2,2-tetrachloroethane (TCE) solutions by using 1H NMR spectroscopy. The block copolymers were synthesized by combination of atom transfer radical polymerization and ring-opening polymerization of N-carboxy amino acid anhydride. Whereas PA homopolymer (H-PAn, n=68) with right-handed helical conformation started to transform to left-handed structure at 70 °C, the helical-sense inversion of PA68-N-PS38 occurred at a lower temperature, 40 °C. Further transformation from left-handed conformation was not observed for both polymers in the temperature range of 70 °C to 110 °C. On the other hand, 1H NMR spectra of PS70-C-PA170 showed coexistence of right- and left-handed helices of PA at 8.2 and 8.8 ppm at 30 °C, respectively. These peaks, however, disappeared above 90 °C, and a new peak at 8.5 ppm was observed. Thus, the introduction of PS chain into PA termini affected conformational stability of PA in a different way, although the transformational behaviors were not influenced by the difference of the chain length of PS segments.

DOI： 10.1295/polymj.pj2007020

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

As a novel synthetic strategy for copolymers of vinyl alcohol, we propose herein copolymerization of alkoxyvinylsilanes with other vinyl monomers, followed by oxidative cleavage of the alkoxysilyl groups attached to the main chain of the resulting copolymers. Radical copolymerization of di(isobutoxy)methylvinylsilane 1 with styrene afforded poly(1-ran-styrene)s with a variety of compositions of both repeating units, although the M-n's (&lt;9000) and yields (&lt;35%) were rather low. The oxidative cleavage of the alkoxysilyl groups in the copolymers with m-chloroperbenzoic acid proceeded efficiently, giving poly(vinyl alcohol-ran-styrene)s, which were soluble in common organic solvents. The structures of the poly(vinyl alcohol-ran-styrene)s were characterized by NMR, GPC, elemental analysis, and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS). (C) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22114

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

The role of cyclophosphazenes with oxyethylene chains (N3P3(OCH2CH2)(n)OCH3, (n = 3, 3, n = 7.2, 4) and N4P4[OC6H4O(CH2CH2O)(7.2)CH3](8) (8) for the synthesis and ionic conductivity in polymethacrylate networks was studied. Reflecting the structural features of cyclophosphazenes, the Li-7 NMR spectra of the mixture of 3 and LiN(SO2CF3)(2) showed that more than 40% of the Li+ salt could exist as a free ion at room temperature. Similar values were obtained for 4 and 8. Cross-linked methacrylate polymers (12-14, and 16-18) were prepared from the reaction of poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate both in the presence of these cyclophosphazenes which act as molecular imprinting molecules (method II, M-II) and without the cyclophosphazene (method I) DSC studies of the imprinted polymer, 12(20)/3/Li+ system after removal of the cyclophosphazene showed that the glass transition temperature range (Delta T-g) becomes significantly narrower compared to that of the unimprinted 11(20)/3/Li+ system, where cross-linked polymer 11(20) was prepared in the absence of the cyclophosphazenes (method I, M-I). The ionic conductivity of the Li+/cross-linked polymer system was improved by the subsequent readdition of the cyclophosphazenes. The 12(20)/3/Li+ complex showed a conductivity of 1.1 x 10(-3) S/cm at 90 degrees C, which was two times higher than that of the 11(20)/3/Li+ complex. The effectiveness of the small molecule imprinting technique for the preparation of cross-linked polyelectrolytes with high conductivity and mechanical stability is discussed.

DOI： 10.1007/s10904-007-9126-3

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Phenyldiazomethane was found to be polymerized by the reaction with palladium-based initiating systems. Homopolymerization of phenyldiazomethane afforded a polymer, whose main chain consists of phenylmethylene framework (-CHPh-) and azo groups (-N=N-). The incorporation of the azo group was suggested from the results of elemental analyses, and confirmed by Raman spectroscopy. Palladium-mediated copolymerization of phenyldiazomethane with (E)-1-diazo-3-nonen-2-one or ethyl diazoacetate proceeded to give copolymers having phenylmethylene framework, azo group, and acylmethylene or ethoxycarbonylmethylene framework in the main chain, with a variety of their compositions. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/pola.21881

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

The anionic polymerization of methyl methacrylate (MMA) was initiated with a mixture of lithium amide of various secondary amines and nBuLi in the presence of YCl3, where an Y-ate complex was formed and an amide ligand on Y attacked MMA nucleophilically. In THF at -78 degrees C, PMMAs with narrow molecular weight distributions were obtained in high yields. The presence of a secondary amino group derived from the initiator at the polymer chain end was confirmed by MALDI-TOF-MS analyses. The initiating system using indoline as a secondary amine was effective for block copolymerization of MMA with tert-butyl acrylate (tBA), giving poly(MMA-b-tBA)s with narrow molecular weight distributions. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jorganchem.2006.08.039

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

alpha,alpha-Dibromotoluene 1 was found to be polymerized by the reaction with excess Mg to give poly(phenylmethylene)s 2, whose main chains were partially dehydrogenated to carbon-carbon double bonds (C=C). The C=Cs in 2 can be brominated by treatment with Br-2. The polymerization mechanism was presumed to include the formation of Grignard reagents of various species with benzylic C-Br bonds and the nucleophilic attacks of the Grignard reagents to various compounds with benzylic C-Br bonds. Copolymerization of 1 with dichlorodimethylsilane successfully proceeded. Mg/Cu-mediated copolycondensation of 1 with 1,6-dibromohexane proceeded to give polymers that have similar compositions to those of random copolymers of ethylene and styrene. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/pola.21637

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Transition metal-mediated copolymerizations of diazocarbonyl compounds with alkynes and an isocyanide were investigated with the following combinations of the comonomers: (E)-1-diazo-3-nonen-2-one (1a) with phenylacetylene (2a), (E)-1-diazo-4-phenyl-3-buten-2-one (1b) with 1-heptyne (2b), ethyl diazoacetate (1c) with 2a and 2b, and 1b with tert-butyl isocyanide (3). All the copolymerizations afforded random copolymers whose GPC traces were unimodal, and H-1 NMR spectra exhibited superposition of signals derived from the repeating units of both comonomers. In addition, the progress of the copolymerizations was supported by the DSC analyses of the products.

DOI： 10.1021/ma0607822

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

The cationic polymerization of isobutyl vinyl ether was examined with transition-metal ate complexes with trityl cation as initiators. The initiators were generated by the reaction of triphenylmethyl chloride [trityl chloride (TrCl)] with ate complexes of Nb, Mo, and W with lithium cation, which were obtained in situ by the reaction of the transition-metal halides with anionic reagents (organolithium or lithium amide). When the polymerization was initiated with a mixture of TrCl and Li+[NbH5(NnBuPh)](-), the resulting poly(isobutyl vinyl ether)s had narrow molecular weight distributions (weight-average molecular weight/number-average molecular weight = 1.13-1.20). Although the polymerization was supposed to be initiated by the electrophilic attack of the trityl cation, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of the resulting poly(isobutyl vinyl ether)s revealed the presence of H at the alpha-chain end. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/pola.21383

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Block copolymers containing PS and PBLG were prepared by combination of ATRP and ring-opening polymerization of BLG-NCA. When PS was attached to N-terminus of PBLG helix of the PBLG was transformed to random coil with addition of TFA in CDC13 solution, which determined by 1H NMR, in accordance with PBLG homopolymer. PS-b-PBLG in which C-terminus of PBLG attached to PS, started helix-coil transformation at lower concentration of TFA.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Improvement of physical properties of vinyl polymers is expected by incorporating norbornene framework into the main chain. Although copolymerizations of various vinyl monomers with norbornene derivatives have been reported, copolymerization using 2-alkoxycarbonyl norbornenes as a comonomer has never been examined to our knowledge. Herein, we will present a new synthetic procedure for methyl 2-norbornene-2-carboxylate (NB-CO 2Me), and radical Copolymerization of NB-CO2Me with alkyl acrylates and other polar monomers.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We report here synthesis and secondary structure of star-shaped polymers composed of poly (ethylene glycol) and poly (glutamic acid) derivatives on the phosphazene core (PEPBLG). The initiator was prepared as follows. Hexachlorocyclotriphosphazene was reacted initially with the sodium salt of APEG to yield the intermediate (PPEG), and then PPEG was successively reacted with HMDA-monoBoc to give PEPAB. The initiator PEPA was prepared by the deprotecting of PEPAB. The ring-opening polymerization of NCA of y-benzyl-L-glutamate with PEPA gave star-shaped polymers with narrow molecular weight distribution. The CD spectra of PEPBLG showed negative peaks at 208 and 222nm, indicating that the polymer chains take α-helical conformation.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We carried out polymerizations of diazocarbonyl compounds by various metal complexes with several ligands as initiators, and investigated the effect of the ligands on the metal center and the addition of amines or Grignard reagents as additives on the polymerization behavior. Polymerization of the monomer 1 was carried out in THF at 50°C for 13h. We found that molecular weights of the polymers depended on the kind of ligand on palladium center as shown in Table 1. Higher molecular weight polymers were obtained by the use of iPrPhNH and pyridine as an additive (run4, 6, 7, 10). In particular, PdCl 2(2-Me-IMD)2 was most effective at giving high molecular weight polymers(run15). Polymerization initiated by other transition metals and polymerization of other monomers than 1 will also be reported.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Block copolymers containing poly(β-phenetyl-L-aspartate) (PPLA) and polystyrene (PS) in which PS was connected at N-terminus (PPLA-b-PS) and C-terminus (PS-b-PPLA) of PPLA segment were synthesized, respectively. PPLA-b-PS showed an irreversible conformational transition from right-handed helix to left-handed helix and a reversible rearrangement of PPLA segment on heating as well as PPLA homopolymer in DSC measurement. On the other hand, PS-b-PPLA showed two irreversible transitions with reduction of their temperature by 20°C and transformed to β-structure in the high temperature region.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

As a novel synthetic strategy for poly(vinyl alcohol) and copolymer of vinyl alcohol, we propose homopolymerization of alkoxyvinylsilanes and copolymerization of alkoxyvinylsilanes with other vinyl monomers, followed by oxidative cleavage of alkoxysilyl groups attached to main chain of the resulting polymers. Radical polymerization of di(iso-butoxy)methylvinylsilane1 afforded poly1. The oxidative cleavage of the alkoxysilyl groups in poly1 with m-chloroperbenzoic acid afforded insoluble product, which was characterized by elemental analysis and IR. We presumed that the product was cross-linked poly(vinyl alcohol). Radical polymerization of di(iso-butoxy)methylvinylsilane1 with styrene afforded poly(1-ran-styrene)s with a variety of compositions of both repeating units, although the Mns(&lt
9000) and yields(&lt
35%) were rather low. The oxidative cleavage of the alkoxysilyl groups in poly(1-ran-styrene) with m-chloroperbenzoic acid proceeded efficiently, giving poly(vinyl alcohol-ran-styrene)s, which were soluble in common organic solvents. The structure of poly(vinyl alcohol-ran-styrene)s were characterized by NMR, GPC, elemental analysis, IR, and matrix-assisted laser desorption time-of-flight mass spectrometry(MALDI-TOF-MS).

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We have reported that anionic polymerization of MMA initiated with transition-metal ate complexes of Nb, Mo, W, where the tacticity of resulting PMMAs depends on the structure of transition metal ate complexes and a highly isotactic PMMA can be obtained by the use of appropriate combination of metal element and ligands. In this report, we will present that the YCl 3/1R2RN/nBuLi systems polymerize MMA in a living manner in THF -78 °C. In addition, anionic block copolymerization of MMA and zBA using the Y ate complexes proceeded to give Poly (MMA-b-tBA) in a living manner.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Recently we have reported that Pd-mediated polymerization of various diazocarbonyl compounds gave poly(substituted methylene)s, which have ester or acyl groups on all the main chain carbon atoms. In this report, the use of organoaluminum compounds as an initiator in place of Pd-compound was examined. The polymerization of (E)-1-diazo-3-nonen-2-one 1 was initiated with 1Bu3Al to give acyl-substituted polymethylenes (poly1) in 41.6% yield. (E)-1-diazo-4-phenyl-3-buten-2-one 2 was polymerized to give poly2 with M n= 1170 in a 30.3% yield. 1H-NMR of the polymer suggested that the side chain acyl groups were partially cleaved to afford unsubstituted CH2n units in the main chain. The degree of the cleavage varied with the kind of R3Al and the feed ratio of the monomer to R3Al.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Recently, we have reported that Pd-mediated polymerization of diazoketones can afford poly(acylmethylene)s bearing acyl groups on all the main-chain carbon atoms. Herein, we will present copolymerization of diazocarbonyl compounds with alkyne by Pd complexes and isocyanide by Ni complexes. Copolymerizations of diazoketone 1a with phenylacetylene 2a and 1b with 1-heptyne 2b initiated with PdCI2(CH3CN)2 proceeded to give copolymers, whose compositions could be controlled by changing the comonomer feed ratios. The progress of the copolymerization of 1a with 2a and 1b with 2b was confirmed by 1H-NMR analyses of the sumples fractionated by preparative recycling GPC and DSC analyses, respectively.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Cyclophosphazenes with six or more reactive sites are useful to prepare star-shaped polymers. We report here the synthesis and secondary structure of star-shaped polyamino acid block copolymers on the phosphazene core (s-PCLL-e-PBLG). The polymer was prepared by the ring-opening polymerization of NCA of Nε-Z-L-Lysine with benzylamine group attached to the phosphazene core, followed by the polymerization of NCA of γ-benzyl-L-glutamate using end amino groups of hexaarmed poly-L-lysine (s-PCLL). The block copolymer (s-PCLL-b-PBLG) (Mi = 58000) has a narrow molecular weight distribution, Mw/Mn = 1.04. The CD spectra exhibited a negative curve at 222 nm, suggesting that most of the block copolymer chains diverging from the core take mainly a right-handed α-helical structure.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We carried out polymerization of various cyclic diazocarbonyl compounds using palladium metal complexes as initiators to prepare new poly(substituted methylene)s, whose main chains were composed of one of the carbons in the cyclic structures. Although homopolymerization of monomer 1 and 2 did not proceed, their copolymerization with acyclic diazoketones gave copolymers with various compositions. On the other hand, homopolymerization of monomer 3 afforded a polymer with Mn=1110 in a 36.4% yield. Copolymerization of 3 with 1-diazo-3-nonen-2-one 5 gave copolymers, whose compositions corresponded to the feed ratios of the comonomers. Poly3 and copolymers of 3 have unique structures, bearing cyclohexenone rings as substituents. Chemical modification of the polymers will be examined by the reaction with various nucleophiles or anionic growing polymer chain ends.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Poly(substituted methylene)s are the polymers whose C-C main chains consist of one carbon repeating unit. We have reported that poly(substituted methylene)s can be prepared from alkyl diazoacetates as monomers via Pd-mediated polymerization releasing dinitrogen. In this report, we will present the synthesis of new poly(substituted methylene)s in which all main chain carbons have a phenyl group, using α, α-dibromotoluene as a monomer. The monomer was reacted with excess Mg in THF at 0°C to room temperature for 20h, giving a polymeric product as yellow powder after purification with recycling preparative GPC. Elemental analysis, UV, and fluorescence spectra of the product indicated that it was a poly(phenyl methylene) with C=C double bonds in the main chain, which were successfully brominated by the reaction with Br2. We examined the use of α, α-dibromotoluene as a monomer for Cu-catalysed polycondensation of 1,6-dibromohexane, which was reported by T. Yamamoto et. al. The successful incorporation of the phenylmethylene units into the polymethylene framework was confirmed by analyses of the copolymer samples fractionated by preparative GPC.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Cross-linked polymer particles were prepared by dispersion polymerization using amphiphilic block copolymers with functional groups, hydroxyl or amino groups, as stabilizers which were prepared by ATRP. Obtained particles were modified by hydrolysis and grafted PBLG or liquid crystal polymer (PA6CB). Dispersibility of these particles for some solvents and effects for liquid crystal were studied.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Synthesis and fluorescence behaviors of Eu3+ ion complexed with polymethacrylate carrying K salt of 4-carboxyphenoxycyclotriphosphazene side group are studied. The multi-armed monomer EPHEMA was prepared from hexachlorocyclotriphosphazene and HEMA, followed by replacement of P-Cl group by HO-C6H4-COO-C2H5. The polymerization of EPHEMA with AIBN afforded PEPHEMA (Mn=25000-402000). The hydrolysis of PEPHEMA gave PKPHEMA without -CO-OCH2CH2- bond scission. The strong fluorescence at 613nm was observed when [Eu 3+]/[KPHEMA]=0.5 was used (λ ex=260nm).

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Synthetic gels are current attention. Despite the interesting application of synthetic gels, their structure is usually poorly controlled. We discuss a new synthesis of polystyrene gels. Molecular weight between cross-linking points and the number of arms at the points in polystyrene gels were regulated by atom transfer radical polymerization and atom transfer radical coupling reaction. Conventional preparation of gels was compared.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We report here synthesis and secondary structure of star-shaped polymers composed of poly (ethylene glycol) or poly (ethylene glycol) methacrylate and poly (glutamic acid) derivatives on the phosphazene core (PEPBLG and PEMBLG). The ring-opening polymerization of NCA of γ-benzyl-L-glutamate with PEPA or PEMK gave star-shaped polymers (Mn=13000-27000). From the spectroscopic data (1H NMR, CD and IR) of PEPBLG and PEMBLG, it appears that the polyglutamate chains take α-helical conformation.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Hierarchical ordering in a side group liquid crystal block copolymer is investigated by differential scanning calorimetry, polarized optical microscopy, small-angle X-ray and neutron scattering (SAXS and SANS) and transmission electron microscopy (TEM). A series of block copolymers with a range of compositions was prepared by atom transfer radical polymerization, comprising a polystyrene block and a poly(methyl methacrylate) block bearing chiral cholesteryl mesogens. Smectic ordering is observed as well as microphase separation of the block copolymer. Lamellar structures were observed for far larger volume fractions than for coil-coil copolymers (up to a volume fraction of liquid crystal block, f(LC) = 0.8). A sample with f(LC) = 0.86 exhibited a hexagonal-packed cylinder morphology, as confirmed by SAXS and TEM. The matrix comprised the liquid crystal block, with the mesogens forming smectic layers. For the liquid crystal homopolymer and samples with high f(LC), a smectic-smectic phase transition was observed below the clearing point. At low temperature, the smectic phase comprises coexisting domains with monolayer S-A,S-1 coexisting with interdigitated S-A,S-d domains. At high temperature a SA,1 phase is observed. This is the only structure observed for samples with lower f(LC). These unprecedented results point to the influence of block copolymer microphase separation on the smectic ordering.

DOI： 10.1039/b510512a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

The anionic polymerization of methyl methacrylate in toluene at -78 degrees C with lithium amides of various secondary amines (diisopropylamine, N-isopropylaniline, N-n-butylaniline, indoline, and N-ethyl-o-toluidine) as initiators was studied. The tacticity of the resulting poly(methyl methacrylate)s (PMMAs) was dependent on the kind of secondary amine, and highly isotactic PMMAs (91-93% mm) were obtained when lithium amides of N-isopropylaniline and N-n-butylaniline were employed. The isotacticity of the PMMAs further increased up to 98% mm with initiating systems composed of the lithium amides, n-butyllithium, and transition-metal halides (WCl6, MoCl5, and NbCl5). (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/pola.20912

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Language：English   Publishing type：Research paper (scientific journal)  

Chirality of S- and R-enantiomer of citronelloxy-cyanobiphenyl (CCB) monolayer on a water surface were investigated by Maxwell displacement current (MDC) and optical second harmonic generation (SHG) measurements. While p-s SHG signal could not reveal the presence of chirality, the polarized angle dependence measurement indicated the ratio between chiral and achiral component of the non-linear optical susceptibility as (χxyz + χxzy)/(χxxz + χxzx) ≈ 1/40 and ≈1/23 for S- and R-CCB, respectively. It was confirmed that our MDC-SHG system has the ability to detect the chirality in monolayer level. © 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2005.03.083

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Palladium-mediated polymerization of diazoketones (1a, 2a, 3a, 4a, and 6a) proceeded to give poly(acylmethylene)s (1b, 2b, 3b, 4b, and 6b), in which all of the main chain carbons had acyl groups. The structures of the novel polymers were characterized by NMR spectroscopy, elemental analyses, and molecular weight measurements (GPC and VPO), where the results of the elemental analyses suggested incorporation of a small amount of azo group (-N=N-) into the main chain (ca. one -N=N- per polymer chain). The presence of a C=C double bond adjacent to the carbonyl carbon in the monomers was required for the polymerization to proceed. Palladium-mediated copolymerizations using a variety of combinations of diazoketones and ethyl diazoacetate, 8, as comonomers proceeded to give various poly(substituted methylene)s.

DOI： 10.1021/ma048293u

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Benzyne generated from fluoride-induced reaction of o-trimethylsilylaryl triflates was found to be copolymerized with pyridine to give novel alternating copolymers bearing o-phenylene and 2,3-dihydropyridine units in the main chain. The unique polymer structures were confirmed from the elemental analyses, MALDI-TOF-MS, and IR, although H-1 NMR spectra of the polymers did not exhibit the signals of protons on the pyridine-derived rings. The copolymers obtained as HCl adducts of pyridine-derived rings can be converted to neutral forms via treatment with NaOH aqueous solution, where nucleophilic attack of hydroxide anion to the pyridine-derived rings resulted in the incorporation of hydroxy and imine groups on the cyclic structure. The mechanism of the copolymerization and the transformation with the alkaline treatment thereafter was proposed. This is the first example that benzyne generated from o-trimethylsilylaryl triflates can be used as a monomer for polymerization.

DOI： 10.1021/ma048668b

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST PURE APPLIED PHYSICS  

We prepared poly(6-[4-(4'-cyanophenyl)phenoxy]hexyl acrylate)s with various molecular weights (M-n) and narrow molecular weight distributions, and examined the M. dependence of phase behavior which includes the reentrant nematic (RN) phase. Polymers with M-n lower than 20,000 form nematic (N), smectic A (SmA) and RN phases as temperature decreases, while ones with M-n higher than 20,000 form only N phase. The disappearance of SmA in longer chains is caused by the decrease in N-SmA temperature and the increase of SmA-RN one with increasing M-n. Result indicates that the polymer length is one of the significant factors affecting the reentrant behavior in side-chain liquid crystalline (LC) polymers.

DOI： 10.1143/JJAP.44.L381

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Amphiphilic block copolymers (PS-b-PAMS) containing polystyrene (PS) and poly(aminomethylstyrene) (RAMS) with various degrees of polymerization (DP) and compositions were used as stabilizers for dispersion polymerizations of styrene or divinylbenzene (DVB), leading polymer nanoparticles with a lot of amino groups on their surfaces. Diameter of PS particle was around 1 μm when DP of PS segment (DPPS) and RAMS segment (DPPAMS) were 20 and 80, respectively. The diameter became shorter with increment of DPPS, which indicates that flocculation and coalescence of the particles were kept out of their polymeric kinetics. PDVB particles were obtained as well as PS particles. The amino groups on their surfaces were changed to ammonium chloride or polypeptide and we observed their variable dispersibility in some solvents.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Poly (substituted methylene)s are the polymers whose C-C main chains consist of one carbon repeating unit. We have reported that poly (substituted methylene)s can be prepared from alkyl diazoacetates as monomers via Pd-mediated polymerization releasing dinitrogen. In this report, we will present the synthesis of new poly (substituted methylene)s in which all main chain carbons have a phenyl group, using α, α -dibromotoluene as a monomer. The monomer was reacted with excess Mg in THF at 0°C to room temperature for 12h, giving a polymeric product as yellow powder after purification with recycling preparative GPC. Elemental analysis, UV and fluorescence spectra, and MALDI-TOF-MS of the product indicated that it was a poly (phenyl methylene) with C=C double bonds in the main chain, which were successfully brominated by the reaction with Br2. The brominated polymer generated cationic charges by the reaction with Me3Al and it reacted with IBVE, giving a graft copolymer. Furthermore, the use of Me2SiCl2 as a comonomer for the polymerization was effective to prepare higher molecular weight polymer.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Block copolymerization of poly(β-phenetyl-L-aspartate) (2PLA) with polystyrene (PS) were successfully carried out by combination of ATRP and NCA method, and obtained 2PLA-b-PS and PS-b-2PLA,in which PS was bonded at N-terminus and C-terminus of 2PLA, respectively. 2PLA-b-PS showed thermally reversible helix-helix transition as well as 2PLA homopolymer in tetrachloroethane which was determined by 1H NMR, while its temperature from right handed helix (PH) to left handed helix (LH) was lower than that of 2PLA homopolymer by 20°C. In PS-b-2PLA, on the other hand, not only PH but also LH already existed at room temperature and transformed into another conformation without helix and random above 70°C which was denoted by appearance of new NH signal at 8.4 ppm. This study clearly shows that each terminus of 2PLA homopolymer has a different role in helix-helix transition.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We have reported that transition metal ate complexes can initiate anionic polymerization of MMA. For example, the WCl6/PhLi/iBu3Al systems polymerize MMA in a living manner, affording high molecular weight PMMAs with narrow molecular weight distribution. In this report, we will present that the YCl3/1R2RN/nBuLi systems polymerize MMA in a living manner in THF -78 °C. Also, anionic block copolymerization of MMA and nBA using the Y ate complexes proceeded to give PMMA-b-P(nBA) in a living manner. In addition, we will present the results of MMA polymerization initiated with transition metal ate complexes of Nb, Mo, W, where the tacticity of resulting PMMAs depends on the structure of transition metal ate complexes and a highly isotactic PMMA can be obtained by the use of appropriate combination of metal element and ligands.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Cationic polymerization of isobutylvinylether (IBVE) was examined by using transition metal ate complexes as initiators. We have found that ate complexes prepared from transition metal halide, Ph3CCI, lithium amide, and nBuLi can initiate the polymerization. In particular, an ate complex of Nb Ph3C+[Nb(nBuPhN)H5]- gave a poly(IBVE) with narrow molecular weight distribution (MWD) (Mn=6000, M w/Mn=1.12) by the polymerization in toluene at r.t. for 62.5h in 60.3%. The polymerization was accelerated by raising the reaction temperature to 40 or 50°C, where the obtained polymers still had narrow MWDs. Poly(IBVE)s with narrow MWDs were not obtained, when ate complexes with different compositions of nBuPhN and H as ligands, and Mo or W as a metal center were employed. MALDI-TOF-MS analysis revealed the chain end structure of the poly(IBVE)s obtained with Ph3C+[Nb(nBuPhN)H 5]-.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Amphiphilic block copolymer containing polystyrene (PS) and poly[(2-hydroxyethyl)methacrylate] (PHEMA) segments was used as a stabilizer for dispersion polymerization of styrene (S) or divinylbenzen (DVB). Size of obtaining PS particles (0.7μm-2.5μm) was controllable with degree of polymerization (DP) and composition of the block copolymer. Flocculation and resulting coalescence of particles were observed with adding DVB to S in the dispersion polymerization. These results mean that the size of the PS particles was owing to their flocculation and coalescence. However, spherical polyDVB particles could not be obtained even if DP of PHEMA segment was 400 and concentration of DVB was decreased to 5 wt% in order to prevent them from the flocculation. On the other hand, post addition of DVB to PS particles could prepare cross-linked particles without flocculation. Hydroxyl groups on their surface were converted in liquid crystalline polymers by ATRP. Effects of the surface exchange were investigated.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Recently our laboratory reported synthesis of poly (substituted methylenes) by palladium-mediated polymerization of alkyl diazoacetates. The obtained polymers have an ester group on every carbon atom of the main chains. In this report, diazoketone compounds are used as monomers for the Pd-mediated polymerization. The polymerization of (E)-1-diazo-3-nonene-2-one was initiated with PdCl2 (MeCN)2 to give acyl-substituted polymethylenes (poly) in 49.6% yield. The structure of the new polymer was characterized by 1H-NMR, GPC, and elemental analysis. The polymerization of (E)-1-diazo-4-phenyl-3-buten-2-one initiated with PdCl2 (MeCN) 2 gave a high molecular weight poly in good yield. The presence of C=C double bond adjacent to the carbonyl carbon in the monomer was required for the polymerization to proceed. Palladium-mediated copolymerization using a variety of combinations of diazoketones and ethyl diazoacetate as comonomers proceeded to give various poly (substituted methylene) s.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Pd-mediated Copolymerization of diazocarbonyl compounds with phenyldiazomethane was examined. The PdCl2/pyridine system was found to be effective for the copolymerization of ethyldiazoacetate with phenyldiazomethane, giving copolymers with the composition expected from the feed ratio of the comonomers. Elemental analyses of the products suggested that azo group (-N=N-) derived from the monomers was incorporated into the main chain, where the presence of the azo group was comfirmed by Raman spectroscopy. When ethyl diazoacetate was employed as a diazocarbonyl compound, the Pd 2(dba)3/pyridine system was effective to give copolymers. Homo polymerization of phenyldidazomethane mediated by the Pd 2(dba)3/pyridine system gave poly(phenylmethylene)s having azo group in their main chain.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

There has been considerable interest in inorganic-organic hybrid polymers with cyclotriphosphazenes, as side groups on carbon main chains. These polymers may provide a new type of materials since the properties and functionalities of polymers can easily be modified by organic groups. We report here the polymerization of methyl acrylates with phenoxycyclotriphosphazene groups, which were prepared from hexachlorocyclotriphosphazene and HEMA, followed by the replacement of P-C1 group by organic units such as 4-hydroxybenzaldehyde and 4-bromophenol. In 1H-NMR spectra of the polymers prepared by radical polymerization, the peak assignable to methylene proton in the main chain was not observed, suggesting that the main chain is surrounded with bulky cyclotriphosphazene groups. As expected, qualitative test of flame retardance indicates that polymers have self-extinguishing properties. Characteristic features and thermal behaviors of polymers will be reported.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Cyclophosphazenes with six or more reactive sites are useful to prepare star-shaped polymers. We report here the synthesis and conformation of hexaarmed amphiphilic polyglutamic acids on the phosphazene core (6p6-PLG). The polymer was prepared by the ring-opening polymerization of NCA of γ-benzyl-L- glutamate with benzoylaminohexylamine attached to the phosphazene core. The six amino groups in the initiator participate in the polymerization without delay, and the hexaarmed polyglutamate formed takes α-helical structure. The pH dependence of 6p6-PLG showed that upon a pH decrease, the helix content increases first rapidly in the pH range from ∼5.0 to ∼4.5, and then slowly in the pH range from ∼4.0 to ∼3.5.

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Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Benzyne generated from fluoride-induced reaction of o-trimethylsilylaryl triflates was found to be copolymerized with pyridine to give novel alternating copolymers bearing o-phenylene and 2,3-dihydropyridine units in the main chain. The unique polymer structures were confirmed from the elemental analyses, MALDI-TOF-MS, and IR, although 1H NMR spectra of the polymers did not exhibit the signals of protons on the pyridine-derived rings. The copolymers obtained as HCl adducts of pyridine-derived rings can be converted to neutral forms via treatment with NaOH aqueous solution, where nucleophilic attack of hydroxide anion to the pyridine-derived rings resulted in the incorporation of hydroxy and imine groups on the cyclic structure. The mechanism of the copolymerization and the transformation with the alkaline treatment thereafter was proposed. This is the first example that benzyne generated from o-trimethylsilylaryl triflates can be used as a monomer for polymerization.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST PURE APPLIED PHYSICS  

We prepared poly(6-[4-(4'-cyanophenyl)phenoxy]hexyl acrylate)s with various molecular weights (M-n) and narrow molecular weight distributions, and examined the M. dependence of phase behavior which includes the reentrant nematic (RN) phase. Polymers with M-n lower than 20,000 form nematic (N), smectic A (SmA) and RN phases as temperature decreases, while ones with M-n higher than 20,000 form only N phase. The disappearance of SmA in longer chains is caused by the decrease in N-SmA temperature and the increase of SmA-RN one with increasing M-n. Result indicates that the polymer length is one of the significant factors affecting the reentrant behavior in side-chain liquid crystalline (LC) polymers.

DOI： 10.1143/JJAP.44.L381

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：INST PURE APPLIED PHYSICS  

This paper reports the first successful preparation of perfectly aligned cylindrical microdomains in liquid crystal (LC) diblock copolymer, polystyrene-block-poly-LC with a poly-LC composition of 84%, by application of a magnetic field. The prerequisite for their alignment is the exhibition of order-disorder transition of the microdomain structure. When the poly-LC segments transform from the isotropic phase to the nematic, well-defined microcylinders are concurrently formed from the weakly segregating state, and their alignment along the magnetic field is realized through the magnetic alignment of LC mesogens.

DOI： 10.1143/JJAP.44.L711

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The ordering of a series of side-chain liquid-crystalline/amorphous diblock copolymers with different molecular weights compositions, and polydispersities is reported. The diblock copolymers comprise polystyrene and poly(methacrylate) bearing methoxy biphenyl mesogenic groups. All samples show a lamellar morphology regardless of their molecular weights, compositions, and polydispersities. Apart from the low-molecular-weight sample, a smectic phase is observed at elevated temperatures. At room temperature, the mesogenic groups partially crystallize. For the sample with the lowest molecular weight the crystalline layers are uncorrelated, and their melting induces the order-to-disorder transition. Samples with relatively long main chains exhibit a three-dimensional ordered crystalline structure with a finite correlation length along the layer normal. This correlation length is longer for the sample with the lowest polydispersity. The mesogenic layers are always perpendicular to the block interfaces. These results can be understood in terms of changes in the conformation of the main chain of the liquid-crystalline block with its length. In thin films, the lamellae orient parallel to the interfaces in an asymmetric fashion with PS at the air interface. At the substrate a thin parallel mesogenic layer is induced. However, this parallel orientation does not propagate into the film interior, and the mesogenic crystalline layers retain their preferred perpendicular orientation with respect to the block lamellae.

DOI： 10.1021/ma0490931

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The combination of potassium tert-butoxide (tBuOK) and triisobutylaluminum (iBU(3)Al) (the tBuOK/iBU(3)Al system) initiated the anionic polymerization of tert-butyl acrylate (tBA) and methyl methacrylate (MMA) and controlled the polymerization with respect to molecular weights and molecular weight distributions (MWDs). Poly(tBA)s (M-n = 20 000-80 000) with narrow MWDs (M-w/M-n = 1.05-1.12) were obtained quantitatively in toluene at 0 degreesC for 1-2 h. The controlled character of the polymerization remained intact even at high temperatures up to 50 degreesC. MALDI-TOF-MS analyses of a low molecular weight poly(tBA) prepared with the initiating system revealed that the polymer had hydrogens at both chain ends. Block copolymerizations of tBA and MMA were also successful in toluene at 0 degreesC by using the initiating system, giving poly(tBA-b-MMA)s with various compositions of the two monomer units and narrow MWDs in high yield. Although the tBuOK/iBu(3)Al system failed to control the homopolymerization of MMA in toluene or THF, the use of diethyl ether (Et2O) as a solvent for the polymerization coupled with cesium fluoride (CsF) resulted in the quantitative formation of high molecular weight poly(MMA)s with narrow MWDs.

DOI： 10.1021/ma030582f

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Hierarchical ordering in a series of side-group liquid-crystal block copolymers was investigated in the bulk via differential scanning calorimetry (DSC), polarized light microscopy, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS). The diblock copolymers comprise a polystyrene block and a block of poly(methyl methacrylate) bearing a chiral biphenyl ester mesogenic unit linked to the backbone by a dodecyloxy spacer. A series of copolymers with different volume fractions of mesogenic block were prepared by atom transfer radical polymerization. Ordering of mesogens into a smectic phase is characterized by a period 3.5 nm. Glass transition temperatures and the clearing temperature for each sample were determined by DSC. Additional ordering occurs due to microphase separation of the block copolymer at a length scale of 22-27 nm, as confirmed by SAXS and SANS. The order-disorder transition was found to be coincident with the smectic-isotropic transition for a sample comprising PS cylinders. A hexagonal morphology was determined for samples with both a minority and a majority liquid-crystal block. Remarkably, the morphology comprising liquid-crystal (LC) cylinders in a polystyrene matrix could be oriented by slow cooling through the clearing temperature, in the presence of a strong magnetic field. The inverse morphology of cylinders formed by the PS block in an LC matrix was not oriented in this way. This is ascribed to the nucleation of defects around the nanorods in the LC matrix. The thin film nanostructure was investigated by atomic force microscopy (AFM) and X-ray reflectivity for a sample comprising PS cylinders. AFM confirmed a hexagonal-packed cylinder morphology in thin films with coexisting parallel and perpendicular orientations of rods with respect to the substrate. The presence of Bragg peaks in specular X-ray reflectivity intensity profiles indicates a proportion of smectic layers lying parallel to the substrate, with a spacing similar to that in bulk. Our results provide a comprehensive picture of hierarchical ordering in the bulk and in thin films.

DOI： 10.1021/ma0498619

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Publisher：Japanese Liquid Crystal Society  

We examined the molecular weight dependence of phase transition behavior for poly(6-[4-(4'-cyanophenyl) phonoxy] hexyl acrylate) prepared by ATRP, which shows reentrant polymorphism with the variation of degree of polymerization (Dp). For the samples with moderate molecular weight (Mn 7,900~20,000) nematic, smectic A and reentrant nematic (RN) phase were exhibited whereas that with higher molecular weight only nematic phase was observed. Furthermore, the difference of dynamics in these two nematic phase has been confirmed by dynamic light scattering (DLS) measurements. The two types of nematic phase is found to be definitely distinguished each other with the two characteristics. This result is ascribed to that the increasing of dimerized mesogen acting as physically linking agents of polymer chains. On the basis of the knowledge, the direct RN-N transition is strongly suggested by DLS measurement for the samples with higher molecular weight.

DOI： 10.11538/ekitou.2004.0.199.0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Atomic force microscopy (AFM) together with SAXS confirms that hierarchical order exists in a side-group liquid crystal block copolymer with a lengthy alkyl chain between mesogen and main chain. The morphology consists of hexagonal-packed PS cylinders in a matrix that contains smectic layers. The decoupling of the mesogens enables them to be oriented by LAOS. AFM indicates a thin film structure consisting of coexisting parallel and perpendicular cylinders that may be kinetically trapped.

DOI： 10.1021/ma0349635

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Anionic polymerization of methyl methacrylate (MMA) was initiated with chromium and vanadium ate complexes generated by the reaction of transition metal trichloride (MCl3: M = Cr, V) with n equiv of lithium diisopropylamide (LDA) (n = 1-3) and 4-n equiv of phenyllithium (PhLi). The MCl3/n LDA/4-n PhLi systems were capable of polymerizing MMA in a living manner in tetrahydrofuran (THF) at -78degreesC, giving poly(methyl methacrylate)s (PMMA) with narrow molecular weight distributions (MWD) in high yield, where the number-average molecular weight (Mn) of the PMMAs increased proportionally with monomer to initiator feed ratio. Matrix-assisted laser desorption inonization time-of-flight mass spectrometry (MALDI-TOF-MS) revealed that the anionic polymerization was initiated by the nucleophilic attack of diisopropylamide (iPr(2)N(-)) group on the transition metal center of the ate complexes and the growing species was stable under the polymerization conditions.

DOI： 10.1295/polymj.35.972

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

The microdomain structure in the blends of liquid crystal (LC)-coil block copolymer with coil homopolymers was studied. The LC-coil block copolymer used is composed of poly(6-[4-(4'-methoxyphenyl) phenoxy] hexyl methacrylate) as a LC segment and polystyrene as a coil segment. It has the molecular weight M-n = 47000 with the LC segment fraction of 45 wt%. As a coil homopolymer, three polystyrenes with different molecular weights of 37000, 26000. and 8200 were used. In all the blends with LC segment fractions of 35% to 10%, the microphase segregation is clearly recognized and LC segment in resulting microdomain undergoes the well defined crystal-SmA-isotropic phase transitions. The microdomain structure depends on both the molecular weight of homopolystyrene blended and the phase structure of LC segment. When the highest molecular weight polystyrene with M-n = 37000 was blended (so called in a "dry-brush" regime), a lamellar type of morphology is invariably observed even if the composition and temperature are varied. In contrast, when the lowest molecular weight polystyrene with M-n = 8200 was used (in a "wet-brush" regime), the type of morphology is significantly altered. At the isotropic temperatures of LC segment, the lamellar morphology is observed for the blends with LC contents from 45% to 35%, but the cylindrical or spherical domain becomes predominant with a decrease in the LC content, On the other hand, the lamellar morphology is commonly observed at the crystal temperatures. In some blends with the lower weight fractions of LC segment, hence, there can be seen the order-order transition from sphere or cylinder to lamella on decreasing temperature. This morphological transformation is caused by the formation of the layered structure that tends to orient perpendicularly to the interface of microdomain. The results show that the structural order of LC segment affects both the microdomain morphology and the solubility style of the homopolymer into the block copolymer.

DOI： 10.1295/polymj.33.783

Web of Science

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Long periodical structure was studied for the crystal of a rigid-rod liquid crystalline BC-6 polyester composed of the 1,4-dihexyl ester of pyromellitic acid and 4,4'-biphenol with small-angle X-ray scattering (SAXS) and transmission electron microscope (TEM) measurements. The highly oriented crystalline fibers which were prepared by spinning a nematic melt of the sample and succeeding annealing showed well-defined scattering maxima with a spacing in the range of 250-300 Angstrom in the SAXS pattern and the corresponding clear stripes in the TEM photograph. The long spacing is attributed to the crystalline lamellae Stacked along the chain axis. This is the first example of long periodical structure in the fully aromatic polymer systems. The origin of the long periodic structure is discussed.

DOI： 10.1021/ma001056g

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

DOI： 10.1080/10587250008024842

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We performed the anionic living polymerization of 6-[4-(4'-cyanophenyl)phenoxy]hexyl methacrylate. By a selection of suitable initiations, the cyano group was completely stable toward the propagating enolate anion, and the anionic polymerization proceeded with a living nature. The homopolymers could thus be prepared with a wide range of molecular weights from 6000 to 20 000, a narrow molecular weight distribution of less than 1.14, and different tacticities. All the polymers exhibited the smectic A phase in which two mesogenic groups were included within a smectic layer of thickness 36.0 Angstrom. The isotropization temperature of the smectic A phase increased with the increase of the molecular weight and leveled off at around 15 000. No crystallization took place so that the smectic A phase was glassified. Well-controlled block copolymers with methyl methacrylate and styrene were also prepared by living anionic polymerization, and their thermotropic phase behavior and structures are described in a relation to a microphase separation of the two different segments.

DOI： 10.1021/ma981366n

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

We have prepared two classes of LC diblock copolymers, OcSt-b-LC and MeSt-b-LC, by living anionic polymerization. These are composed of the side-chain LC polymer as one segment and two different amorphous polymers, poly(octyl styrene) (OcSt) and poly(alpha-methyl styrene) (MeSt), as the other segment. OcSt and MeSt segments have glass transition temperatures of -60 degrees C and 160 degrees C respectively, which are relatively lower and higher than the transition temperatures of crystal-S-A (similar to 90 degrees C) and S-A-isotropic (similar to 130 degrees C) in the LC segment. In OcSt-b-LC the lamellar domain size decreases gradually from that of the crystal phase to that of the isotropic phase, indicating that the global conformation of the backbone changes throughout the SA temperature region. In MeSt-b-LC, in contrast, no change in the lamellar size is observed and the crystallinity of the LC segment is reduced in comparison with that in OcSt-b-LC while the liquid crystal is well formed. Such a distinction between two copolymer systems, arising from an interplay between the LC and amorphous segments, shows that the global conformation of the backbone is significant for understanding the phase behaviour and structure of side-chain LC polymers.

DOI： 10.1088/0954-0083/10/1/014

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Other Link： http://orcid.org/0000-0001-8579-939X

Language：Japanese   Publishing type：Book review, literature introduction, etc.  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館  

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Event date： 2024.11

Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Language：Japanese   Presentation type：Poster presentation  

Venue：とりぎん文化会館   Country：Japan  

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Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

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Event date： 2024.9

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

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Event date： 2024.9

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

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Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Ehime Kyosai Kaikan   Country：Japan  

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Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Ehime Kyosai Kaikan   Country：Japan  

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Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Ehime Kyosai Kaikan   Country：Japan  

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Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Ehime Kyosai Kaikan   Country：Japan  

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Event date： 2024.7

Language：English   Presentation type：Poster presentation  

Venue：Ehime Kyosai Kaikan   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館  

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Event date： 2024.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2024.5

Language：Japanese   Presentation type：Oral presentation (invited, special)  

Venue：愛媛県産業技術研究所   Country：Japan  

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Event date： 2024.5

Language：Japanese   Presentation type：Poster presentation  

Venue：愛媛県産業技術研究所   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山口大学工学部   Country：Japan  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山形大学工学部   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

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Event date： 2023.11

Language：Japanese   Presentation type：Poster presentation  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.11

Language：Japanese  

Venue：かめ福オンプレイス   Country：Japan  

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Event date： 2023.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：香川大学   Country：Japan  

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Event date： 2023.9

Language：Japanese   Presentation type：Poster presentation  

Venue：香川大学   Country：Japan  

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Event date： 2023.9

Language：Japanese   Presentation type：Poster presentation  

Venue：香川大学   Country：Japan  

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Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo Convention Center   Country：Japan  

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Event date： 2023.7

Language：English   Presentation type：Oral presentation (general)  

Venue：Sapporo Convention Center   Country：Japan  

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Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2023.7

Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Language：Japanese   Presentation type：Poster presentation  

Venue：兵庫県民会館   Country：Japan  

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Event date： 2023.5

Language：Japanese   Presentation type：Poster presentation  

Venue：Gメッセ群馬  

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Language：Japanese   Presentation type：Poster presentation  

Venue：Gメッセ群馬   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.12

Language：Japanese   Presentation type：Poster presentation  

Venue：香川県県民ホール   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島大学   Country：Japan  

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Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.9

Language：Japanese   Presentation type：Poster presentation  

Country：Japan  

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Event date： 2022.9

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Event date： 2022.7

Language：Japanese   Presentation type：Oral presentation (general)  

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Venue：愛媛大学  

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