Faculty Profiles - UCHIDA Tetsuya

Papers - UCHIDA Tetsuya

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Electrooxidation of alcohols in a disperse system with N-oxyl-immobilized polyethylene particles as disperse phase and aqueous NaHCO3/NaBr as disperse media: A totally closed electrolysis system Reviewed

H Tanaka, J Kubota, S Itogawa, T Ido, M Kuroboshi, K Shimamura, T Uchida

SYNLETT 7 ( 7 ) 951 - 954 2003.6

Language：English Publishing type：Research paper (scientific journal) Publisher：GEORG THIEME VERLAG KG

Electrooxidation of alcohols was performed successfully in a disperse system with N-oxyl immobilized polyethylene particles as disperse phase and an aqueous saturated NaHCO3 solution involving 20 wt% NaBr as disperse media. The N-oxyl immobilized polyethylene particles were prepared by heating a suspension of polyethylene particles (3 x 3 x 0.02 mm(3)) in fuming nitric acid at 80 degreesC for 1 h followed by treatment with 4-amino-2,2,6,6-tetramethylpyperidine- 1-oxyl in chlorobenzene in the presence of DCC. Recycle use of the N-oxyl-immobilized polyethylene particles and the aqueous media was performed successfully without significant change of the yields of the products and current efficiency, thereby offering a totally closed electrolysis system.

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剛直高分子三次元架橋体およびその複合体の構造と物性 Reviewed

内田哲也, 島村薫, 木村邦生

繊維学会誌 59 ( 6 ) 207 - 212 2003

Poly(ethylene-block-vinylalcohol) film with amphiphilic surface at high temperature Reviewed

K Shimamura, Y Munesawa, T Uchida, N Hikasa

POLYMERS FOR ADVANCED TECHNOLOGIES 13 ( 3-4 ) 205 - 209 2002.3

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

Poly(ethylene-block-vinylalcohol) (PE/PVA), which consisted of both hydrophobic and hydrophilic blocks, was prepared by using polyethylene single crystals as starting material. Polyethylene single crystals were reacted with fuming nitric acid resulting in long methylene chains with functional groups such as COOH and NO? at the ends (the chain lengths were almost the same as the lamellar thickness of polyethylene single crystal). The functionalized methylene chains were allowed to react with 4-aminostyrene to give corresponding amides, i.e. methylene chains with vinyl groups at the ends (macromer). The macromers were extended by block-copolymerization with vinyl acetate, then saponified resulting in PE/PVA block copolymer.
The block copolymer was molded into sheets which were subsequently heat-treated in contact with hydrophilic or hydrophilic media. Depending on the media, the sheet surface changed at high temperature reversibly from hydrophilic to hydrophobic and vice versa. Die surface property was fixed by quenching because both blocks were able to crystallize. Thus the surface of this material can be tailored for various purposes at high temperature, and then used in stable condition at room temperature. Copyright (C) 2002 John Wiley Sons, Ltd.

DOI： 10.1002/pat.174

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Observation of a solitary rigid molecular chain cilium standing on poly(p-phenylene benzobisthiazole) lamellar crystal Reviewed

K Shimamura, T Uchida

JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS B41 ( 3 ) 529 - 537 2002

Language：English Publishing type：Research paper (scientific journal) Publisher：MARCEL DEKKER INC

The rigid polymer, poly(p-phenylene benzobisthiazole), crystallized from H2SO4, formed a lamellar crystal in which the polymer chains were oriented perpendicular to the lamellae. It was supposed that the lamellar surface bristled with chain cilia because of wide distribution in the polymer chain length. This region of the bristle would be a transitional structure from full to deficient packing of the polymer chains. Ordinary scanning probe microscopy of the bristled lamellar surface permitted depiction of a layer with a constant population of the cilia. In this work, the method for imaging one single polymer chain end standing on the lamellar surface was developed. From the image it was concluded that an isolated, long cilium did not move extensively at room temperature. In addition, the three-dimensional chain end distribution was determined by several tens of scannings with consecutively varying input energy of the cantilever.

DOI： 10.1081/MB-120004351

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Polymer supported N-Oxyl mediated electrooxidation of alcohols in aqueous NaBr/NaHCO3 Reviewed

H Tanaka, M Kuroboshi, J Kubota, S Itogawa, T Ido, T Uchida, K Shimamura

REACTIVE INTERMEDIATES IN ORGANIC AND BIOLOGICAL ELECTROCHEMISTRY 2001 ( 14 ) 17 - 20 2001

Language：English Publishing type：Research paper (international conference proceedings) Publisher：ELECTROCHEMICAL SOCIETY INC

Electrooxidation of alcohols 1 was performed successfully in an aqueous disperse system with N-Oxyl-immobilized polyethylene particles (PE-N-Oxyl) as the disperse phase and an aqueous saturated NaHCO3 containing 20 wt.% of NaBr as the disperse media. Work-up process is quite simple; thus, polymer perticles were separated by filtration and washing with EtOAc and the filtrate and the washings were combined, extracted with EtOAc, dried (Na2SO4) and concentrated in vacuo to afford the corresponding ketones 2. The recovered PE-N-Oxyl as well as the aqueous disperse media could be repeatedly used for the electrooxidation of 1 without significant change of the yields of the ketones 2.

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Whisker of poly(p-oxybenzoyl-co-p-mercaptobenzoyl) - Influence of sequence on polymer morphology Reviewed

K Kimura, D Nakajima, K Kobashi, Y Yamashita, F Yokoyama, T Uchida, Y Sakaguchi

POLYMERS FOR ADVANCED TECHNOLOGIES 11 ( 8-12 ) 747 - 756 2000.8

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

Aromatic polymers are expected to possess outstanding properties. However in many cases they do not show good processability because of their chain regidity. We have been studying the morphology control of rigid polymers during polymerization to overcome this problem and succeeded in preparing the whiskers of poly (p-oxybenzoyl) and poly (p-mercaptobenzoyl) by the polymerization in liquid paraffin at around 300 degreesC. These whiskers are formed by the reaction induced crystallization of oligomers during solution polymerization.
The preparation of copolymer whiskers is very interesting to design the new materials which are endowed with novel functions. The aim of this study is to prepare the whisker of poly (p-oxybenzoyl-co-p-mercaptobenzoyl) and to clarify the influence of the copolymerization on the morphology, especially focusing on the sequence regularity. The introduction of comonomer unit into polymer chain structure extinguishes the crystal habit due to the lower crystallizability and the whiskers can be obtained by the random copolymerization of 4-acetoxybenzoic acid (ABA) and S-acetyl-4-mercaptobenzoic acid (AMBA) only when chi (f) (the molar ratio of ABA/AMBA in feed) is 1.0-0.7 and 0.05-0. However, the copolymer whiskers are obtained by the polymerization of OS, OOS and SSO monomers which produce the alternating and periodic copolymers. These copolymer whiskers consist of the alternating or periodic copolymer chains and their chains align along the long axis of the whisker. The sequence regularity enhances the crystal lizability of cooligomers and this lends to the formation of the whiskers. The sequence regularity in copolymers is a very influential parameter to control the morphology and the copolymer whiskers can be prepared by giving the regular sequences. Copyright (C) 2000 John Wiley & Sons, Ltd.

DOI： 10.1002/1099-1581(200008/12)11:8/12<747::AID-PAT53>3.0.CO;2-4

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Super structure formation in a wholly aromatic copolyester fiber Reviewed

Tetsuya Uchida, Kaoru Shimamura

Polymers for Advanced Technologies 11 ( 4 ) 198 - 202 2000.4

Language：English Publishing type：Research paper (international conference proceedings) Publisher：John Wiley & Sons Ltd

The structure of a wholly aromatic copolyester fiber containing 60 mol% p-hydroxybenzoic acid (PHB), 20 mol% 4-4'-dihydroxydiphenyl, 15 mol% terephthalic acid and 5 mol% isophthalic acid was studied by means of electron microscopy and wide-angle X-ray diffraction. The X-ray diffraction pattern of the wholly aromatic copolyester fibers showed two sets of diffractions: one set was composed of sharp spots which arose from relatively high crystalline phase. The crystal structure analyzed by these spots was orthorhombic and the lattice dimensions were a = 0.869 nm, b = 0.510 nm, c = 1.20 nm and ρ = 1.50 g/cm3. Another set was characteristic of streaks on the meridian extending parallel to the equator. X-ray scattering intensity distribution on the meridian was calculated as the square of Fourier transform of random chain model. Comparison of this intensity distribution with the observed meridional maxima concluded that the streaks were due to rather disordered chains with a PHB content of less than 50%. Dark field image (DFI) taken from the meridional 002 reflection showed that slender crystallites were distributed over the whole visual field, oriented parallel to the fiber axis. On DFI from the equatorial 200 reflection, some of these crystallites were also observable, forming groups that distributed randomly in the field. All crystallites belonging to the same group co-oriented in a(*)- and c(*)-axis directions, though disordered parts intervened among the crystallites. This is attributed to the fact that, though the content of PHB in the segments of disordered parts was only 50%, these PHB held the co-orientation among the slender crystallites within one group. Heat treatment induced the development of block segment and subsequent crystallite growth with fiber. This reorganization improved the thermostability and the mechanical properties. Copyright (C) 2000 John Wiley and Sons, Ltd.

DOI： 10.1002/1099-1581(200004)11:4<198::AID-PAT970>3.0.CO;2-1

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Morphology and structure of poly(p-phenylene benzobisthiazole) crystals Reviewed

K Shimamura, T Uchida

JOURNAL OF MACROMOLECULAR SCIENCE-PHYSICS B39 ( 5-6 ) 667 - 677 2000

Language：English Publishing type：Research paper (scientific journal) Publisher：MARCEL DEKKER INC

The rigid polymer poly(p-phenylene benzobisthiazole) (PBZT) was crystallized from dilute solution. Electron microscopy showed that, on quenching, flat fibrils several nanometers thick were produced. Subsequent heat treatment in a solvent changed the morphology from fibrillar into "segmented ribbon" structure. Isothermal crystallization at a temperature of about 30 degreesC below the dissolution temperature, in general, resulted in aggregation of rod crystals. The polymer chains were oriented normal to the rod crystals. The width of the rod crystal increased with average molecular length, but saturated to a value much smaller than the average molecular length. In the shorter molecular length range, the rod crystals clustered in a fanned-out manner, while with a medium molecular length (ca. 70-120 nm), all rods crystals in a cluster aligned parallel to each other and were of the same length. With longer molecular length (more than ca. 180 nm), the rod growth slowed because of small diffusion constants of molecular chains to the growing face. Based on observation of the morphology and the crystallization process, an isothermal crystallization mechanism is proposed. Because of the rigidity and wide length distribution of polymer chains, the chain ends were inevitably included within the crystals, resulting in crystal defects such as axial shifts, lattice curvatures, and edge dislocations, all of which were observed directly by lattice imaging.

DOI： 10.1081/MB-100102478

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Visualized Polymers. Patterns Formed by Polymeric Systems. II. Structure of Extruded-Blown Film of High Density Polyethylene. Reviewed

MURAKAMI Syozo, KOHJIYA Shinzo, UCHIDA Tetsuya, SHIMAMURA Kaoru

Kobunshi Kagaku 56 ( 12 ) 828 - 831 1999

Language：Japanese Publisher：The Society of Polymer Science, Japan

Structure of the extruded-blown film of high density polyethylene was studied by X-ray diffraction, SEM, and SPM. Lamellar bundles were piled up along the extrusion direction and oriented perpendicular to the extrusion direction. Close observation by SPM revealed that one lamellar bundle which looked like a single lamella by SEM was actually composed of ca. 6 lamellae. We propose that formation of such lamellar bundles may be due to self-vibration by rubbing with a die during the extrusion of melt.

DOI： 10.1295/koron.56.828

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Crystallization of poly (p-phenylene benzobisoxazole) from dilute solution Reviewed

Kaoru Shimamura, Tetsuya Uchida, Makoto Suzuki, Chunxiao Zhang

Sen'i Gakkaishi 54 ( 7 ) 374 - 378 1998

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

PBZO's having average molecular length of 27,49 and 128 nm were crystallized from dilute solution in conc.H2SO2. At high crystallization temperature, the shorter PBZO (L∼30nm) formed lath shaped lamellar crystals. Electron diffraction indicated that the long axis of the lamella to be along the crystallographic b-axis forming 100 twins, and that the molecular chains was perpendicular to the lamella. High resolution electron micrograph showed that 100 lattice fringe had an orientation distribution and curved within one crystallite. Decrease in crystallization temperature and/or increase in the chain length changed the morphology essentially into flat fibrils. Branchings through repetitive twinning across {100} and [formula-ommited] planes lead to a square network. Vacancies in the fibrillar network were finally filled by post lamellar growth resuting in a mosaic structure, except with PBZO of the longest molecular chain. Oriented rigid cilia on the lamellar surface facilitated the growth rate of daughter crystals and regulated their orientation. © 1998, The Society of Fiber Science and Technology, Japan. All rights reserved.

DOI： 10.2115/fiber.54.7_374

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Branched Poly(p-phenylene benzobisthiazole) Crystallized from Dilute Solution Reviewed

Kaoru Shimamura, Michio Ishitobi, Tetsuya Uchida, Makoto Suzuki

sen'i gakkaishi 50 ( 3 ) 101 - 104 1994

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

Poly(p-phenylenebenzobisthiazole) P (PBZT) chains with average molecular length of 61 nm have been reacted with trimesic acid to link each other. The product, a mixture of Y-, V-shaped and linear P (PBZT)'s, was dissolved into conc.SCU at a concentration of 0.1 wt%, and isothermally crystallized. The precipitate was composed essentially of curved rod-like crystals. Four or five crystals having different length coagulated each other with many branches at an angle of ca 60°. This morphological feature was in contrast to that of pure linear P (PBZT) precipitate in which several tens straight rod-like crystals of the same length were oriented parallel to each other to make a group. This difference in morphology between linear P (PBZT) and the mixture of Y, and V-shaped and linear P (PBZT)'s was well explained by the crystallization mechanism of P (PBZT). 100 lattice fringe was observed throughout the central area of the rod-like crystal. This means that the center was composed of linear part of Y-, V-shaped and linear polymers, which were accomodated normal to the rod. In some area, the 001 lattice fringe crossed 100 lattice fringe at an angle of ca 75°, suggesting that P (PBZT) unit cell might not be Fratini's monoclinic type. On both sides of the 100 lattice fringe, there were dark belts. These belts corresponded to thick parts which were composed of the other counterparts in the Y- and V-shaped poly mers. © 1994, The Society of Fiber Science and Technology, Japan. All right reserved.

DOI： 10.2115/fiber.50.3_101

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