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Volume 57, Issue 2
Displaying 1-7 of 7 articles from this issue
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Sadaatsu YAMAGUCHI, Masayoshi TATEMOTO, Masaki TSUJI2000 Volume 57 Issue 2 Pages 59-66
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSFine particles of ca. 30nm in diameter were morphologically discussed on the basis of the transmission electron microscopic [TEM] observations of the emulsion particles of fluoro rubbers and fluoro resins such as vinylidene fluoride-hexafluoropropene copolymer, poly (vinylidene fluoride) [PVDF] and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer [PFA]. Fine particles were also observed on the fractured surface of a PVDF sheet obtained by injection molding. A test piece cut out from this PVDF sheet was dissolved in N, N-dimethylacetamide [DMA] and the resultant PVDF solution was cast onto water. The thin film of PVDF was formed on the water surface. Particles of ca. 0.2-0.3 μm in diameter were observed in this film. The solution of PVDF was poured into well-stirred water, and accordingly fibrous precipitates were obtained. Fine particles of ca. 20-40 nm in diameter were observed on the surfaces of the fibrous precipitates by the three-stage replica method. Consequently it seems that molecular chains constituting the fine particles are not entangled randomly in the molten state or in the concentrated DMA solution, but only the chains located at the boundary between fine particles are entangled and the remaining chains inside of a particle are isolated from another particle.View full abstractDownload PDF (12011K) -
Shin-ichi INOUE, Mihoko HIRAKO, Hiroshi OKAMOTO2000 Volume 57 Issue 2 Pages 67-71
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPolyurethane elastomer was prepared from polycaprolactone (PCL), diphenylmethane diisocyanate (MDI), 1, 4-butanediol (1, 4-BD) and Trimethylolpropane (TMP) by prepolymer method. This amine catalyst was used: 1, 4-diazabicyclo- (2, 2, 2) octane (DABCO). Effects of the catalyst on molecule structure and physical properties of polyurethane elastomer were also studied. When a catalyst was used, the reaction rate was rapider than with the non-catalyzed system. In the observation of the polarizing microscope, some spherulites of small hard segments were found dispersed in the soft segments. In the defferential scanning calorimetry (DSC) measurements, the transition width which originated from the glass transition temperature (Tg) of amorphous hard segments become larger, and it became clear that phase mixing of the hard segment advances. In the mechanical properties, by using amine catalyst, the elastic modulus in the extension rose in comparison with non-catalyzed PUE, and the build-up of the stress was observed in the extension over 300%. A remarkable elongation drill effect was shown. Also, the stress relaxation slowed down, and so the stress continued throughout the long term and the elasticity rose.View full abstractDownload PDF (2704K) -
Minoru TSUBOTA, Katsura NAGANUMA, Takao UEHARA2000 Volume 57 Issue 2 Pages 72-77
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIn this paper, we propose a detection method of Tg for the cross-linked polymer particles by applying the dynamic viscoelasticity measurements. The typical kinds of polymer particles were dispersed in amino alkyd resin solution, and the baked coating films of these composites were prepared. The temperature dependence curves of tanδ for these films showed that two components existed along with the phase separation structure of polymer blend. From the temperature of the tanδ peak corresponding to the polymer particles, we obtained a reasonable Tg for all particles used, but some of them we could not detect by differental scanning calorimetry (DSC) method. The merits of Tg evaluation method from tanδ were clarified, and compared with those of DSC method.View full abstractDownload PDF (1172K) -
Hiroyuki SUZUKI, Ion SAKAI, Kaori OTSU, Akiyoshi KAWAGUCHI2000 Volume 57 Issue 2 Pages 78-85
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSBy two-staged roll-drawing of the three layer sheets where a ultra high molecular weight polyethylene (UHMW-PE) layer is sandwiched by ultra high molecular weight isotactic polypropylene (UHMW-iPP) layers, we tried to prepare a film which exhibits excellent mechanical properties. The temperature range available to roll-draw at the first stage of the stacked sheet is 125-135°C and that at the second stage of the specimens drawn once is 130-145°C The highest draw ratio (DR) was performed at a drawing temperature of 135-140°C at the second stage. By differential scanning calorimetry (DSC) of the thus-prepared specimens, we observed endothermic peaks originating from various crystalline states, i. e. folded-chain crystals and extended-chain crystals even at low DR of about 20. From the X-ray diffraction of the films, it was recognized that the roll-drawing easily induces the double orientation of PE. By comparison with the specimen which was uniaxially drawn to same DR for the tensile modulus and strength, the advantage for the mechanical property of the roll-drawn specimen in two-stages was recognized.View full abstractDownload PDF (3789K) -
Hiroyuki SUZUKI, Hidekazu NAKANISHI, Takanori KATOH, Shigeru IMAI, Aki ...2000 Volume 57 Issue 2 Pages 86-94
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPoly-p-phenylene (PPP) thin films were deposited on non-heated silicon (100) substrate by the synchrotron radiation (SR) ablation method using as-synthesized PPP powder as a source. The deposited thin films were characterized by Raman scattering spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Raman spectra and the FT-IR spectra showed that the thin films consisted of PPP molecules which had comparatively long molecular chains equivalent to those for the as-synthesized powder. The XRD spectra showed that the thin films had comparatively high crystallinity without heating the substrate. Stick-like and assembled organization of the surface of the thin films was observed from the SEM micrographs. In situ quadrupole mass spectrometry (QMS) of the product generated during SR irradiation to PPP showed that most of the species generated after decomposition by SR irradiation to PPP is the monomer. The process of the deposition of the PPP thin films using the SR ablation method was discussed from the results.View full abstractDownload PDF (3840K) -
Hidetoshi HIRAHARA, Shirou ABE, Kunio MORI, Yoshiyuki OISHI, Ichirou T ...2000 Volume 57 Issue 2 Pages 95-99
Published: February 25, 2000
Released on J-STAGE: July 27, 2010
JOURNAL FREE ACCESS2, 4-bis- (4-morpholinyl trithio) -6- (N-allyle-1H, 1H, 2H, 2H-perfluorododecylamino) -1, 3, 5-triazine (RfTDM) was synthesized from 6N-allyl-1H, 1H, 2H, 2H-perfluorododecylamino-1, 3, 5-triazine-2, 4-dithiol and 4, 4′-morpoline disulfide under acidic media. The fluorination of acrylonitrile butadiene rubber (NBR) treated with RfTDM solution was investigated using contact angle measurments, X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR) FTIR and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The surface of NBR treated with RfTDM solution showed IR absorption peaks of triazine ring at 1544 cm-1 and of fluoro methyl fluoro metylene groups at 1300-1100cm-1. XPS revealed that CF3 groups of RfTDM was oriented at the surface of NBR. The fragments of the fluorine were confirmed by the TOF-SIMS analysis of the surface of NBR surface-treated RfTDM, RfTDM was adsorbed on the NBR surface. The contact angle for the water on the NBR surface which was treated with RfTDM was 115 deg. As RfTDM treatment time increased, the surface free energy of NBR surface decreased. The surface of NBR showed a wetting property guite similar to that of the polytetrafluoroethylene. The RfTDM treatment is a method for giving waterrepellent and oil-repellent functions on the NBR surface.View full abstractDownload PDF (958K) -
Youichi KUROKAWA, Yuko IKEDA, Motoi KOUNO, Takayuki ISHIZAKA2000 Volume 57 Issue 2 Pages 100-104
Published: February 25, 2000
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSS. cerevisiae cells have been entrap-immobilized on titanium iso-propoxide-cellulose acetate fiber by using the gel formation. Entrapped cells were compared with native cells for ethyl alcohol fermentation and β -keto ester (ethyl acetoacetate) biotransformation. The entrapped fibers can be used in phosphate media, in which conventional entrapped alginate will dissolve. However, it was found that, when the cells grew with an increase of reaction period, then one part of the grown cells were released from entrapped fiber.View full abstractDownload PDF (2374K)
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