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Volume 54, Issue 10
Displaying 1-22 of 22 articles from this issue
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Shinichi Sakurai, Akio Yoshida, Shigeyoshi Furuhara, Shunji Nomura1998 Volume 54 Issue 10 Pages 491-495
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSTime evolution of phase separation in a polymer blend solution under a temperature gradient was studied using polystyrene (PS), polybutadiene (PB), and dioctylphthalate (DOP). This study is aimed at making a highly organized structure by using convection. A blend solution with PS/PB/DOP=2/2/96 by weight was placed into the spacer (thickness 0.1 and 0.3mm) of which top and bottom temperatures were kept at 50 and 60°C, respectively. Phase separating processes were observed with a phase-contrast microscope. For 0.3-mm thickness, a polygonal cellular pattern due to convections was formed and phase-separated droplets were mainly arranged in the boundary region of each polygonal cell. For 0.1-mm thickness, quite different structures and a grow process were observed. At a dynamically steady state, doubly-surrounded island-sea structures were observed, where a larger droplet contains a plenty of tiny droplets which are arranged near the interface.View full abstractDownload PDF (2634K) -
Yoichi Nakashima, Mitsuru Tahara, Hirokazu Kimura, Toru Takagishi1998 Volume 54 Issue 10 Pages 496-501
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe surface structures of wool fibers treated with the glow discharge under atmospheric pressure and the low-temperature plasma were mainly examined by SEM. The ruggedness morphologies, which were caused by the oxidation-etching effects, were observed on the surface of specimens treated with oxygen low-temperature plasma. The morphology of the specimens treated with low-temperature plasma of helium gas flow was little changed compared with original one. In the case of glow discharge under atmospheric pressure, numerous granules with a diameter of ca. 0.15μm appeared on the cuticle layer. These granules were completely soluble in methanol. According to the XPS spectra, such granular materials consist of substances containing large amount of carboxyl group. It was suggested that such granules were composed of polar compounds with lower-molecular weight which were different from the original substance of wool fiber. It is likely that the granular materials are degraded products of the proteins in surface layer generated partly by the glow-discharge energy and remained on the surface of wool fibers due to the atmospheric pressure.View full abstractDownload PDF (2447K) -
Koji Ishizu, Takashi Ikemoto, Ayako Ichimura1998 Volume 54 Issue 10 Pages 502-505
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe ribbon-like nanopolymers were prepared by the crosslinking reaction of poly (α-methylstyrene)-block-poly (4-vinylpyridine) (PMS-block-P4VP) diblock copolymer films exhibiting P4VP cylindrical microdomains, with the vapour of 1, 4-dibromobutane in the solid state. It was indicated by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) that these crosslinked products had a structure of ribbon-like nanopolymers.View full abstractDownload PDF (1740K) -
Asako Hirai, Masaki Tsuji, Fumitaka Horii1998 Volume 54 Issue 10 Pages 506-510
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSAcetobacter xylinum produces cellulose in the form of a twisted thin ribbon assembly. Handedness of the twisted ribbon assembly was examined by transmission electron microscopy (TEM). Special care for correct up-and-down setting of specimens and photographic films was taken to determine the handedness of the twisted assembly by TEM. The ribbon cellulose assemblies were prepared on TEM grids using ATCC 23769 and ATCC 10245 and then shadowed with Pt-Pd. They all showed right-handedness. Splayed microfibrils were prepared from smooth colony of ATCC 23769 by the addition of carboxymethyl cellulose sodium salt (CMC) (DP=80 and DS=0.57) into the culture medium. A bundle of them was twisting together in one body in the right-handed manner.View full abstractDownload PDF (3197K) -
Tomoko Hongo (nee Hirasaki), Chihiro Yamane, Masatoshi Saito1998 Volume 54 Issue 10 Pages 511-515
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe surface morphology of various regenerated cellulose fibers was observed by atomic force microscopic method under dry and wet states. For Lyocel, long and slender microfibrils with ca. 10_??_20nm diameter were aligned along the fiber axis. Commercially available cupro (Cupro-1) had fibrils with ca. 80_??_200nm diameters. On the surface of anti-fibrillation type cupro (Cupro-2) and viscose rayon (Rayon), the well developed microfibrils were not clearly observed and anisotropy of the particles constructing the microfibril or aggregate was lower than those of Lyocel and Cupro-1. The tendency of fibrillation occurring under wet state was in the order of Lyocel>Cupro-1>Cupro-2_??_Rayon and this order was just corresponding to the degree of the anisotropy of the particles. The surface morphology was changed by wetting in the order of Rayon_??_Cupro-2>Cupro-1>Lyocel. The degree of connection of the particles along the fiber axis (DCP) was also in the latter order. The degree of crystalline orientation was just in reverse order. The decrease of the tensile strength by wetting was larger for the fiber with lower DCP. DCP and the anisotropy were considered to govern the lowering of the wet tensile strength and the fibrillation tendency for the regenerated cellulose fiber.View full abstractDownload PDF (1400K) -
Rumiko Fujioka, Yuri Inamasu, Sei-ichi Manabe, Kiyohisa Imada1998 Volume 54 Issue 10 Pages 516-519
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSWe intend to reveal the fine structure of regenerated cellulose fibers in a solvent from the change in interference color observed by polarizing microscopy. Two kinds of cellulose hollow fibers, which show different contribution in the orientation between the molecular chains and the intermolecular hydrogen bond (plane orientation), were used. The interference colors of fibers changed with the immersing solvent. The orientation of the solvent molecules adsorbed on the interfacial surface (order adsorption) was deduced from the interference color. This order adsorption was affected by the orientation property of the fiber. The thermal molecular motion and the change in fine structure can be evaluated quantitatively through the change in interference color with increasing temperature. The temperature dependence of the color related closely to the diffusion of solvent molecules.View full abstractDownload PDF (1627K) -
Seiji Tokino, Yoshio Wada, Mitsuo Ueda, Tomiji Wakida1998 Volume 54 Issue 10 Pages 520-522
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSPoly (p-phenylene terephthalamide) films, poly (phenylene sulfide) films and poly (m-phenylene isophthalamide) fibers were irradiated with a XeCl excimer laser to modify their surface structure. The change in surface morphology of laser-irradiated polymer materials was found to be dependent on the laser irradiation angle. At an irradiation angle of 60° or 45°, anisotropic roll -like structure was created by the laser ablation. The friction coefficient of the poly (m-phenylene isophthalamide) fibers changed with the laser irradiation angle. The fibers irradiated at an irradiation angle of 90° did not show any directionality in the friction coefficient, while the fibers irradiated at an angle of 60° or 45° showed the directionality in the friction coefficient.View full abstractDownload PDF (1530K) -
Sadaatsu Yamaguchi1998 Volume 54 Issue 10 Pages 523-526
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe tensile strength and the morphology of polytetrafluoroethylene skived tapes and poly (vinyliden fluoride) sheets molded at 665Pa were investigated by tensile testing with an autograph and by transmission electron microscopy.
The tensile strength of the tapes and sheets molded at 665Pa was greater by about 10% than that molded at atmospheric pressure. The bands observed at the surface of the polytetrafluoroethylene skived tape molded under reduced pressure were about 1.4 times wider than those at the surface of the tape molded at atmospheric pressure. Spherulites were observed at the surface of poly (vinylidene fluoride) sheet molded at atmospheric pressure, but were not recognized at the surface of the sheet molded at 665Pa. It seems that at atmospheric pressure a microvoid containing air and/or gases worked as a nucleus of the spherulite.View full abstractDownload PDF (1859K) -
Suong-Hyu Hyon1998 Volume 54 Issue 10 Pages 527-531
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe surface morphological changes in poly-L-lactide (PLLA) fibers subjected to in vitro hydrolysis at 37°C and 100°C have been investigated by observation with scanning electron microscopy.
PLLA was melt-spun in air at 200°C with an extruder of screw-type. Hot drawing and heat treatment of the fibers were conducted at 80_??_160°C. The wide-angle X-ray diffraction patterns of the drawn fibers showed appreciable crystalline orientation. Hydrolytic degradation of as-spun and drawn fibers was conducted in distilled water at 37°C and 100°C. The tensile strength after 6 months at 37°C dropped only 10 % with no change in water. On the other hand, hydrolysis at 100°C caused a 100 % decreased in tensile strength for fiber within 20 hr. SEM examination of these fibers revealed regular patterns of cracks running in the vertical direction to the fiber axis.View full abstractDownload PDF (2007K) -
Eri Munekane, Tetsuo Kanamoto, Roger S. Porter1998 Volume 54 Issue 10 Pages 532-537
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSUltrahigh molecular weight polyethylene reactor powder has been drawn in the crystalline state by two-stage coextrusion at 120°C to a total extrusion draw ratio (EDRt) of 24. EDRt is a product of the EDR's for the two stages. The flaws generated by coextrusion draw have been characterized by polarized photomicroscopy, wide-angle X-ray diffraction, and atomic force microscopy. The effect of flaws within drawn products on the stress/strain behavior was also observed. Two kinds of flaws, i.e., kink bands running at an angle of 45-75° to the fiber axis and significant variations of sample thickness along the fiber axis, have been observed. The generation of these flaws, which were not present in a superdrawn single crystal mat, was found to be strongly dependent on the combination of the first-stage EDR and the second-stage EDR. The mechanism for the formation of flaws is not known at present, and is currently under study.View full abstractDownload PDF (2187K) -
Tatsuhiro Takahashi, Hirokazu Nakajima, Yuichi Masubuchi, Jun-ichi Tak ...1998 Volume 54 Issue 10 Pages 538-543
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSUniaxial elongational viscosity of low density polyethylene (LDPE) gave the strain-hardening property. However, talc-filled LDPE showed almost no strain-hardening property and glass-fiber-filled LDPE exhibited the strain-softening property. The cause of almost no strain-hardening property or strain-softening property was discussed from flow observation of internal deformation using visual model experiments. Silicone gums including a glass bead or a glass fiber with a black silicone gum marker were elongated. The internal strain in a glass-bead-filled system was larger than the external strain along the elongational axis, and the received internal strain was larger around a particle than far way from a particle. The internal strain in a glass-fiber-filled system did not depend on the location when the initial orientation of the fiber was perpendicular to the elongational direction. While, the received internal strain next to the fiber without the both edges was almost none when the initial fiber was parallel to the elongational direction. Nonuniformities of internal flow by the addition of fillers seem to be associated with no strain-hardening property or strain-softening property.View full abstractDownload PDF (2086K) -
Fernando A. Novillo L., Masahiro Fujita, Masaki Tsuji, Shinzo Kohjiya1998 Volume 54 Issue 10 Pages 544-549
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSSolution-cast thin films of poly (ethylene 2, 6-naphthalate) (PEN) were isothermally crystallized at 190°C on the highly oriented ultra-thin friction-transfer layer of polytetrafluoroethylene (PTFE), after being melted at 300°C. Transmission electron microscopy (TEM) of the films showed that PEN crystallized in an oriented fashion on the layer. Selected-area electron diffraction (ED) indicated that the crystals in the PEN films are mostly the α-form, as expected from our thermal condition for crystallization. The ED pattern from the untilted specimen was characterized by the fairly intense arc-shaped 010 reflection on the equator. A series of ED patterns, which were obtained from the same specimen area tilted at various angles around the axis parallel or perpendicular to the chain axis of PTFE in a TEM column, suggested that the crystallites of PEN α-form are preferentially oriented with their chain axis being parallel to the chain axis of PTFE and moreover, with their (100) planes being parallel to the surface of the PTFE layer.View full abstractDownload PDF (2528K) -
Tetsuya Tanigami, Kaoru Nemoto, Koji Yamazaki, Nobuyuki Maruyama1998 Volume 54 Issue 10 Pages 550-554
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe phase structure consisting of mm-sized domains has been found in the blend films of two types of at-poly (vinyl alcohol) s with 99 and 89 mol% of the degrees of saponification, named samples Ao and Bo, respectively, around a 40/60 (=Ao/Bo (wt/wt)) blend composition. The domains strongly contacted with their surrounding matrix against mechanically applied force. However, the domains Bo-rich could become an empty hole by soaking the film in water. These results indicate possibility of producing porous films from the phase separated blend films.View full abstractDownload PDF (2037K) -
Tamaki Mitsuno, Ryoko Goto, Kazuo Ueda1998 Volume 54 Issue 10 Pages 555-561
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSEffect of pressure stimulation to the waist on the skin temperature of the hand was examined by thermography in 2 women subjects. They were pressured around their waists on all sides by using a waistband of 2.5cm width. Pressure stimuli of 2-minute duration were applied twice at 4-minute intervals and their intensities ranged from 5 to 20 Torr (from 6.8 to 27.2 gf/cm2). Waistband pressures, developed between the waistband and the abdominal skin, were measured by a hydrostatic pressure-balanced method. In both subjects, the apparent skin temperature of dorsum manus decreased when their waists were pressured by even a 5 Torr. It can be concluded that analysis of the skin temperature is useful to examine the effect of weak pressure on the human body.View full abstractDownload PDF (1615K) -
Junzo Masamoto, Kimihiro Kubo1998 Volume 54 Issue 10 Pages 562-567
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSFor use as electrical and electronics parts, automobile and mechanical parts, toughened poly (phenylene sulfide) (PPS) is desired. Our investigation centered on improving the toughness of PPS and developing elastomer toughened PPS. Using chemically-treated PPS and an olefinic elastomer with a functional group, we developed elastomer toughened-PPS using a reactive extrusion processing method. In the PPS matrix, the elastomer is finely dispersed. While the notched Izod impact strength of the original PPS is about 10 J/m, elastomer-toughened PPS has a notched Izod impact strength of around 500 J/m. The notched fracture surface of elastomer-toughened PPS is observed by using a scanning electron microscope. We concluded that the mechanism for the toughening is attributed to energy absorption by matrix yield. We checked how the difference in the reactive extrusion processing method affects the elastomer dispersion. When PPS and olefinic elastomer were extruded without a chemical modifier, it gave a large elastomer particle size and brittle material. When PPS and olefinic elastomer were extruded with a chemical modifier (this reactive extrusion process is called the one-step extrusion), it gave a mixed combination of elastomer with large and small particle sizes and a tough material. When chemically modified PPS was extruded with olefinic elastomer (this reactive extrusion process is called the two-step extrusion), it gave a uniformly dispersed elastomer with a small particle size. Considering the fact that both the reactive one-step extrusion and two-step extrusion methods gave a tough material with a same order, elastomer particles with a small size were thought to contribute to the toughness of PPS.View full abstractDownload PDF (2912K) -
TOSHIO HAYASHI1998 Volume 54 Issue 10 Pages P344-P349
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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TATSUO HIYOSHI1998 Volume 54 Issue 10 Pages P350-P354
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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MORIO MIYAGI1998 Volume 54 Issue 10 Pages P355-P358
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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TAKEYUKI KAWAGUCHI1998 Volume 54 Issue 10 Pages P359-P364
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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KOHJI TASHIRO1998 Volume 54 Issue 10 Pages P365-P369
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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YOSHIKAZU TAKATERA1998 Volume 54 Issue 10 Pages P370-P373
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
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TAKAKO TOKUYAMA1998 Volume 54 Issue 10 Pages P374-P375
Published: October 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (787K)
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