Sen'i Gakkaishi
Online ISSN : 1884-2259
Print ISSN : 0037-9875
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Volume 66, Issue 10
Displaying 1-13 of 13 articles from this issue
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  • Application of Dithiol Compounds in Supercritical Carbon Dioxide to Improve the Adhesive Properties of Copper-Plated p-Aramid Fibers
    Magali Belmas, Isao Tabata, Kenji Hisada, Teruo Hori
    2010 Volume 66 Issue 10 Pages 229-235
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2115/fiber.66.229
    JOURNAL FREE ACCESS
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    Supercritical carbon dioxide (scCO2) has been used to impregnate the organometallic complexes in a synthetic polymer prior to electroless copper plating. However, this method has not been applied to highly crystalline and highly oriented polymers, such as p-aramid fibers. In this study, triazine dithiols were used to create a network that consisted of Kevlar® fibers, the organometallic complex palladium (II) hexafluoroacetylacetonate [Pd(hfa)2], and a metal layer. This network improved the adhesion of a copper layer that was added by electroless plating. Three triazine thiols were used, two of which were soluble in scCO2 and one of which was soluble in water. Pretreatment of the Kevlar® fibers comprised two steps : 1) impregnation with a thiol compound, using sc-CO2 or the thiol-water solution ; and 2) impregnation with an organometallic metal complex using sc-CO2. Electroless plating was performed to coat the treated Kevlar® fibers with a layer of copper. By changing the experimental conditions (i.e., pressure, temperature, thiol concentration, and order of impregnation), we found that the triazine thiol improved the electrical resistivity and adhesion of the copper layer.
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  • Role of the Stereocomplex Crystallites in the PLLA/PDLA Mixed Spinning Dope on the Stereocomplex Formation in the Wet-spun Fibers
    Lee Jun Jae , Hideki Yamane
    2010 Volume 66 Issue 10 Pages 236-242
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2115/fiber.66.236
    JOURNAL FREE ACCESS
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    Wet-spinning of the PLA fibers was carried out from the mixed solution of PLLA and PDLA in CHCl3 held for various periods of time after preparation. The solution immediately after preparation indicated a low viscosity and a good spinnability. The viscosity and the storage modulus increased and the spinnability deteriorated with increasing holding time indicating a partial network formation with stereocomplex crystallites as crosslinking points. The as-spun fiber obtained from the solution held for a long time contained both the homo-crystal and the stereocomplex crystal as revealed by WAXD measurements. Although the HC crystal in the fiber spun from the solution held for short time was not eliminated, the SC crystal turned to be a major crystalline form in the fiber after drawing and annealing processes at an elevated temperature, when the fibers were spun from the solution held for long time. These results indicate that the stereocomplex crystallites in the mixed solution of PLLA and PDLA promote the stereocomplexation during the coagulation process. Furthermore, the stereocomplex crystallites dispersed in the fiber also promote the stereocomplexation in the fiber during the annealing process acting as a nucleating agent for the stereocomplex crystal.
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  • Impregnation of Cyanuric Chloride into Synthetic Fabrics (PET and PP) by Supercritical Carbon Dioxide and its Application in Immobilizing Natural Biomacromolecules
    Wen-Xiao Ma, Satoko Okubayashi, Kazumasa Hirogaki, Isao Tabata, Kenji ...
    2010 Volume 66 Issue 10 Pages 243-252
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2115/fiber.66.243
    JOURNAL FREE ACCESS
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    Biomacromolecules (sericin or chitosan) were immobilized onto the surface of synthetic fibrous fabrics (PET and PP) via a cross-linking agent of cyanuric chloride. Prior to the immobilization of biomacromolecules, cyanuric chloride was introduced to the fabric surface by an impregnation treatment in scCO2. The impregnation process was optimized by a variety of treatment parameters, such as ressure, temperature and time, and with or without co-solvent. The immobilization process was performed in an aqueous system. A detailed surface characterization was conducted after each process step using the following techniques : ATR-IR, XPS and SEM. The hydrophilicity of the modified fabrics was assessed by measuring water contact angle and wicking rate. The results show improvements in surface wettability and water absorption ability in the odified fabrics of PET and PP, especially for the CC-PET fabrics finished by biomacromolecules (sericin or chitosan).
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  • Preparation, Structure Analysis and Enzymatic Degradation of Poly [(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] Gel-films
    Taizo Kabe, Toshihisa Tanaka, Ken-ichi Kasuya, Kazuki Ito, Masaki Taka ...
    2010 Volume 66 Issue 10 Pages 253-260
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2115/fiber.66.253
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    Gel-films of poly[(R)-3-hydroxybutyrate-co-(R)-3- ydroxyhexanoate] (P(3HB-co-3HH)) with 12 mol% 3HH comonomer were prepared from a dilute solution of 1,2-dichloroethane by rapid quenching and slow drying. Uniaxial drawings were applied to the gel-films at room temperature. The gel-films were possible to stretch up to 8 times, leading to enhancements of the mechanical properties. The tensile strength, Young's modulus, and elongation to break of 8 times drawn gel-film were 151 MPa, 0.21 GPa, and 58 %, respectively. The orientation of lamella crystals in gel-films and drawn gel-films were analyzed by wide-angle and small-angle X-ray diffraction. In the drawn gel-films, a planer zigzag conformation consisting of extended molecular chains was observed. Furthermore, the lamella crystals in drawn gel-film were revealed to orient two directions, which are parallel and perpendicular to the film surface. It was indicated that a part of the oriented lamella crystal parallel to film surface rotated in the direction of perpendicular to the film surface during drawing of the gel-film. The drawings of gel-films accelerated the rate of enzymatic degradation by PHB depolymerase. The result was explained that the planer zigzag conformation in the drawn gel-films was easier to be broken down by the enzyme than the lamella crystals.
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Technical Papers
  • Effects of Ultraviolet Radiation on the Color of Compounded Papers Containing Wasted Tea Leaves
    Tetsuya Takahashi, Wakako Kasai, Tetsuo Kondo
    2010 Volume 66 Issue 10 Pages 261-266
    Published: 2010
    Released on J-STAGE: November 19, 2010
    DOIhttps://doi.org/10.2115/fiber.66.261
    JOURNAL FREE ACCESS
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    Influence of ultraviolet irradiation on papers containing wasted tea leaves was studied. Ultraviolet irradiation generally caused reddish coloration. Irradiation under dry atmosphere caused stronger coloration than under ambient conditions. Presence of oxygen did not cause significant difference in coloration. Thin-layer chromatographic analysis showed disappearance of chlorophylls a and b, and did not disappearance of theaflavin by UV irradiation. The results strongly suggest that the coloration is caused by photochemical conversions of catechins to reactants (theaflavin-like compounds).
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