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Volume 52, Issue 9
Displaying 1-15 of 15 articles from this issue
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Shigemitsu Murase, Kouji Kakumoto, Kazushige Kudo1996 Volume 52 Issue 9 Pages 450-456
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSStructure and properties of ultra-high speed spun nylon 66 [poly (hexamethylene adipamide)] fibers prepared at take-up speeds of 5 to 12km/min were investigated through the X-ray and thermal analyses and the measurements of mechanical properties. With an increase in the take-up speed, both Young's modulus and dynamic storage modulus increased monotonously, while tenacity reached a maximum at around 6km/min. Birefringence and amorphous orientation function also showed a maximum. In contrast with these results, density showed a tendency of saturation at high-speed region. The existence of void in the filament was also suggested by the smallangle X-ray scattering measurement. From the wide-angle X-ray diffraction analysis, the increase in the crystalline orientation function, crystal perfection index and the thickness of lamellar were observed with an increase in the take-up speed. Thus, it was concluded that highly ordered crystalline structure was formed in the high-speed spinning of nylon 66 fibers. The existence of peak in tenacity was related with the formation of the void in the filament and the increase of Young's modulus was related with the ordering of crystalline structure.View full abstractDownload PDF (910K) -
Nobuo Ogata, Sugio Kawakage, Tatsuo Ogawa, Teruaki Yanagawa, Takashi O ...1996 Volume 52 Issue 9 Pages 457-464
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSNylon 6-clay hybrid (NCH) was a nanocomposite consisting of nylon 6 and montmorillonite; the silicate layers of montmorillonite were well dispersed individually in the matrix of nylon 6. Five extruded strands with different clay contents and films were prepared. The structures of the NCH extrudates and NCH films were investigated by wide angle and small angle scattering methods. In NCH extrudates, silicate layers were oriented along the extrusion direction and the fiber axis of the γ-type crystallites of nylon 6 was oriented perpendicular to the extrusion direction. In NCH films, not only the hydrogen-bonded sheets of nylon 6 crystallites but also the surface of the silicate layer were found to be parallel to the film surface. Such preferred orientations of the silicate layer and the nylon 6 crystallites suggested the presence of an interaction between them. This interaction hindered the crystal transformation from γ to α types, which took place during the heat treatment and drawing process.View full abstractDownload PDF (2226K) -
Kiyoko Kawasaki, Toshiro Suzawa1996 Volume 52 Issue 9 Pages 465-472
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSInterfacial electrical properties of ultrafine polyester fiber and regular polyester fiber and deposition of polymer latices onto these fibers were studied. The polymer latices used were polystyrene [PS] and polystyrene/acrylamide [P(St/AAm)] copolymer latices, both prepared without emulsifier. Conductometric titration and ζ-potential measurement of these fibers showed that acidic groups are much more abundant on the ultrafine fiber polyester much more than on the regular polyester fiber, and that acidic groups of the former are likely to be strong acids, while those of the latter are weak acids. The relative swelling degree of the ultrafine polyester fiber was greater than that of the regular polyester fiber. These facts indicate that the ultrafine polyester fiber is more hydrophilic than the regular polyester fiber. The ζ-potential decreased and deposition of latices onto the both fibers increased at acidic pHs. The deposition of the latices onto the ultrafine polyester fiber were much greater at acidic pHs than a neutral and alkaline pHs. The same tendency was observed with the regular polyester fiber. The P(St/AAm) latex deposited onto the ultrafine polyester fiber more strongly than the PS latex. This tendency was the same as with the regular polyester fiber. These results indicate the bridging effect between the polymer chain of P(St/AAm) latex and these fibers.View full abstractDownload PDF (550K) -
Kiyohiro Inoue, Hideki Kikuchi, Shigeo Asai, Masao Sumita, Seigo O-oya1996 Volume 52 Issue 9 Pages 473-480
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDifferent samples of poly (L-lactic acid), which were prepared from the melt via quenching (at -50°C) followed by annealing and via slow cooling, were analyzed by WAXS and DSC measurement. The results suggested that the amorphous regions of quenched film are different from the amorphous regions of the quenched film annealed at 60°C, while other quenched samples annealed at 80-120°C seemed to have disordered crystallites. Hydrolysis degradation tests, which were carried out on those samples in 1N NaOH solution at room temperature, revealed that the samples treated at 100°C were degraded more rapidly than the quenched samples. This suggests that annealed samples contain easily hydrolyzable sites, such as voids and crystal defects. It was also observed that the hydrolyzed samples have three different patterns of degradations: 1) decrease of thickness with a regular wearing, 2) the edge of film shows complicated surface boundary and 3) a cracked film surface of small pieces. The photographs of sample surfaces were also taken and analyzed by an image analysis technique. From these observations, degradation process can be analyzed by means of Fractal dimensions and the Fractal model (modified random von Koch curve).View full abstractDownload PDF (985K) -
Tooru Taga1996 Volume 52 Issue 9 Pages 481-487
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSST/amylose graft product which had been prepared using ceric ammonium nitrate as initiator and from which homo polystyrene had been almost completely removed by tetrahydrofuran extraction was re-extracted with 10% NaOH aq. solution to yield a transparent extract solution. UV spectrum determined for the extract showed the absorption intrinsic to phenyl group. ST/cellulose graft product which had been prepared from gel cellulose by the same procedures as described above was subjected to the extraction with 85% phosphoric acid to give a transparent extract solution. The UV spectroscopy on the extract solution indicated the presence of phenyl group in the solution.
Molecular weights of the graft polystyrene chains separated from the extracts by means of complete hydrolysis of polysaccharide chains were far smaller than those of trunk polymers.
It may be concluded that polysaccharide graft copolymers whose graft polymer chains are far smaller than trunk polymers in molecular weight dissolve in the good solvents for the trunk polymers, under suitable conditions.View full abstractDownload PDF (494K) -
Yoshihiko Onogi, Aoi Yabuuchi, Chikako Matsuda1996 Volume 52 Issue 9 Pages 488-492
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSCotton cloth coated with a fluorocarbon polymer lost its water repellency with rubbing but the repellency was recovered by a heat treatment. Rubbing of the cloth reduced its water repellency due to detachment of the water repellent film covering the textile fibers. The repellency also decreased by the introduction of water molecules into the water repellent film by rubbing with other cloths. These observations were verified from changes in the contact angle of water and electric surface resistance caused by the heat treatment of the rubbed cloths. Water molecules could also be introduced by dipping the finished cloth into hot water. The introduced water molecules could not be removed completely by vacuum drying at room temperature.View full abstractDownload PDF (352K) -
Masamichi Morita, Hiroko Ogisu, Motonobu Kubo1996 Volume 52 Issue 9 Pages 493-499
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSWater repellency of perfluoroalkylethyl acrylate (FA)/n-alkyl acrylate (AA) copolymers was dependent on the side chain length of the AAs. The surface properties were studied by dynamic contact angle, static contact angle and freeze-dried XPS, and the bulk ones by wide-angle X-ray diffraction and DSC. Water repellency was discussed from a standpoint of the molecular mobility of perfluoroalkyl (Rf) groups on the surface. The advancing contact angles for water were 120° and independent of the side chain length of AAs. The phenomenon was attributed to the orientation of Rf groups in air regardless of side chain length of AAs. On the contrary, the receding contact angles showed small values of about 45° for the carbon number of alkyls of AAs (n) below 8 and increased suddenly with increasing n above 12. From these results, the mechanism of water repellency was explained as follows. Low water repellency at n below 8 results from the regression of Rf groups from the water-solid interface to minimize the interface free energy. High water repellency at n above 12 shows that the motion of Rf groups was restricted due to crystallization of side chains. This mechanism was supported by other measurements.View full abstractDownload PDF (482K) -
Fumio Taki1996 Volume 52 Issue 9 Pages 500-503
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDescaled wool fibers were obtained by the treatment with potassium hydroxide in dehydrated butanol at 50°C for 17 h under gentle agitation. The modification of the cortex was examined by amino acid analysis and the damage tests of the cortex. The amino acid contents of the descaled wool samples were consistent with those of cortical cells reported by Bradbury and Peters. The optical anisotropy was well retained. These results suggest that the descaled wool fibers were obtained whose cortex structure was almost unmodified by the present treatment.View full abstractDownload PDF (1155K) -
YUICHI IBARAKI1996 Volume 52 Issue 9 Pages P357-P361
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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TERUYUKI MATSUKI, [in Japanese], [in Japanese]1996 Volume 52 Issue 9 Pages P362-P365
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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ROKURO MORISHITA1996 Volume 52 Issue 9 Pages P366-P369
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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HARUO NIWAYA1996 Volume 52 Issue 9 Pages P370-P374
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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AKIHISA INOUE1996 Volume 52 Issue 9 Pages P375-P381
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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YASUHIRO OI, MITSURU WAKITANI1996 Volume 52 Issue 9 Pages P382-P384
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
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MASAYUKI ONOUE1996 Volume 52 Issue 9 Pages P392-P395
Published: September 10, 1996
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (321K)
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