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Volume 61, Issue 2
Displaying 1-10 of 10 articles from this issue
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Satoshi USUKURA, Yuiichi IKEDA, Hiroaki KOUZAI2004 Volume 61 Issue 2 Pages 95-101
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSWe have introduced a oxidation decomposition of large scrap tires and small scrap tires using hydrogen peroxide (H2O2) /formic acid (HCOOH). The optimum conditions were H2O2 10mL, HCOOH 20mL, 60°C, 1-2 hours against a 20g sample. The results of the determination of the distillates by IR spectroscopy and other analysis indicate that the water-soluble and methanol-soluble components are composed of relatively low-molecular weight compounds containing -OH, C=O and-COOH groups as well as active oxygen and sulphur, though there is a small difference between the two portions. The remaining portion after the oxidative distraction is composed of rubber material and softening agent. These materials were thermally decomposed separately. The thermal decomposition material was carbon black.View full abstractDownload PDF (1343K) -
Yukihiko INOUE, Tadahiro SATO, Atsushi KOBAYASHI, Noritaka OHTANI2004 Volume 61 Issue 2 Pages 102-106
Published: February 25, 2004
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESSThis report describes the swelling behavior of cationic acrylamide gels which contain dodecylsulfate counter ions in water/organic solvent mixtures. The gels, which shrank in water, exhibited a sharp volume increase when the organic solvent content of the solvent mixture reached a certain concentration. The concentration varied with ion content of the gels and with the kind of organic solvents. This volume increase was thought to be caused by the destruction of the aggregate of dodecylsulfate ions that had formed in the gels.View full abstractDownload PDF (1035K) -
Kenji KIKUCHI, Yoshihiko UENO, Takuji OKAYA2004 Volume 61 Issue 2 Pages 107-113
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe aqueous polymerization scheme of acryl amide with a redox system composed of cysteine and persulfate ion at controlled pH as well as the hydrogen ion generation scheme the during polymerization in this system were studied kinetically. The analyses of these reaction schemes were performed with a numerical method. The initiation reaction in this system was based on the formation of complexes composed of persulfate ion, cysteine and acrylamide. The propagation reaction was found to be the reaction between acrylamide monomer and the complex formed from polymer radical and acrylamide. The order of the polymerization reaction of acrylamide of 1.8 was concluded to be due to the complex formation reactions.View full abstractDownload PDF (1238K) -
Jun TAKAHASHI, Hideki WATANABE, Jun NAKAMOTO2004 Volume 61 Issue 2 Pages 114-121
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSImpact resistance and transparency of methylmethacrylate-butadiene-styrene resin (MBS resin) with a bimodal distribution of rubber particle sizes were investigated. Rubber-modified MBS resin was selected as contributing large rubber particles. Emulsion graft polymer was selected as contributing small rubber particles. The blends were evaluated focusing on falling weight impact strength. The falling weight impact strength was improved by the bimodal distribution, but the tendency was different for Charpy notched impact strength. The transformed rubber particles and voids were observed in the TEM photographs of whitened area, and crazing was not observed. Not only the falling weight impact strength but also transparency was improved by the bimodal distribution.View full abstractDownload PDF (3558K) -
Takashi KUWAHARA, Kenji OSHIMA, Takeshi YAMAUCHI, Masato SHIMOMURA, Sh ...2004 Volume 61 Issue 2 Pages 122-126
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESS3-Methylthiophene/thiophene-3-acetic acid (3MT/T3A) copolymer films were fabricated by electrochemical polymerization and glucose oxidase (GOD) was immobilized covalently on the films. Conductivity of the copolymer films was found to increase with decreasing content of T3A units. An almost constant amount of GOD was immobilized on the copolymer films whose contents of T3A units were larger than 30%. The activity of immobilized GOD was not affected remarkably by 3MT/T3A ratio in the copolymer films used. Amperometric sensing of glucose with the GOD-immobilized copolymer films gave the result that large response currents were observed by use of the copolymer films with a low content of T3A units. The result suggests that the sensitivity depends on the conductivity of the copolymer films as well as the activity of immobilized GOD.View full abstractDownload PDF (1104K) -
Shoji YOSHIMOTO, Masaki KATO, Yasushi OHNISHI2004 Volume 61 Issue 2 Pages 127-132
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPolypyrrole composite films were prepared by chemical oxidative polymerization of pyrrole using poly (vinyl alcohol) (PVA) or poly (vinyl acetate) (PVAc) as a matrix polymer. These films were applied to measure their resistance changes by exposing to methanol vapor. It was found that the surface morphologies of composite films vary with the matrix polymer. On exposure to methanol vapor, the PPy-PVA film exhibited an increase in its resistance, similar to that of a p-type semiconductor. On the contrary, PPy-PVAc decreased in filmresistance. The results indicate that the matrix polymer plays an important role for defining the responses of film resistance.View full abstractDownload PDF (2082K) -
Masato SHIMOMURA, Ryo TOGASHI, Kenji OSHIMA, Takeshi YAMAUCHI, Shinnos ...2004 Volume 61 Issue 2 Pages 133-138
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSCopolymerization of acrylic acid and acrylamide was carried out in a redox system consisting of mercapto groups introduced onto the surface of magnetite particles and ceric ions, and acrylic acid-acrylamide copolymer was grafted onto the particles. Glucose oxidase (GOx) was immobilized on the magnetite particles by condensation with carboxyl groups of the grafted copolymer. An optimum value of pH for the GOx immobilized on the copolymer-grafted magnetite was observed between that for native GOx (pH 4-5) and that for the GOx immobilized on poly (acrylic acid) -grafted magnetite (pH 7). It was found that the value of optimum pH showed a tendency to increase with increasing amount of acrylic acid units in the grafted copolymer. These results were attributed to the effect of remaining carboxyl groups of the grafted polymer to acidify the surface of magnetite particles. This effect was confirmed by a clear correlation observed between the zeta potential of magnetite particles and content of carboxyl groups on the particles.View full abstractDownload PDF (1189K) -
Yasuhiko ONISHI, Yasuo KIKUCHI2004 Volume 61 Issue 2 Pages 139-143
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDEAE-dextran is an important substance used for transfer of nucleic acids into cultured mammalian cells. The transfection of a mammalian cell is accomplished via the complexation between nucleic acids and DEAE-dextran. Such complexes were thus synthesized using the RNA from a yeast under various conditions including reaction time and pH, and analyzed by IR absorption spectroscopy and DSC. From the relation between the yield, pH, and reaction time, the optimum pH was in the range 5-10. The relation between the weight ratio of RNA/DEAE-dextran in the complex, pH, and reaction time indicated the ratio to be 0.25-0.55 in the pH range 5-10. The IR absorption spectra and DSC curves confirmed that the complexes were formed by the coulomb force between a single and tandem DEAE-group in DEAE-dextran and phosphoric acid in the RNA.View full abstractDownload PDF (2358K) -
Eiji SATO, Tatsuhiro TAKAHASHI, Kiyohito KOYAMA2004 Volume 61 Issue 2 Pages 144-148
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIt was found that both ends of the vapor-grown carbon fiber (VGCF) were clearly observed by SEM on the cover glass through dispersing VGCF in a polycarbonate (PC) /tetrahydrofuran (THF) solution and decomposing PC by heat treatment. By using this method, the length of three kinds of VGCF before and after mixing was measured: untreated VGCF (average diameter: 150nm), VGCF treated for densification, and VGCF which was melt-mixed with PC using a twin screw extruder. SEM analysis suggested that the average length of VGCF has become short by densification treatment or melt mixing from 6.7μm to 3.9μm or to 3.0μm, respectively. The present study proposed a new simple method to evaluate VGCF length, and demonstrated the evidence for breakage of VGCF by mixing.View full abstractDownload PDF (2266K) -
Takafumi YAMABE, Touhei YAMAMOTO2004 Volume 61 Issue 2 Pages 149-151
Published: February 25, 2004
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNew hydrophilic crosslinked polymers comprising poly (vinyl alcohol) (PVA) and poly (ethylene glycol) (PEG) units were synthesized using sulfuric acid as a dehydration catalyst. When the molecular weight of PEG unit was high, the degree of the reaction was low. In contrast, a high degree of the reaction was attained when a low molecular weight PEG was used as a crosslinker.View full abstractDownload PDF (612K)
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