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Volume 73 (2016)
- Issue 6 Pages 491-
- Issue 5 Pages 389-
- Issue 4 Pages 341-
- Issue 3 Pages 225-
- Issue 2 Pages 139-
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Volume 73, Issue 4
Displaying 1-8 of 8 articles from this issue
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Special Topic on Fiber Materials II
Original Papers
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Toshiaki MIYATA, Akiyoshi TAKENO, Yuta MISHIMA, Shinya TAKAHASHI2016 Volume 73 Issue 4 Pages 341-346
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: May 17, 2016JOURNAL FREE ACCESSMicrobubbles with diameters less than 50 µm have some unique properties different from millimeter-sized bubbles. They are already used in various industrial applications, but their use in textile industries is limited. The ozone microbubbles produced by pressing gas through a porous film have a high oxidation potential. In this paper, we describe the surface modification of polyester by such bubbles. The concentration of dissolved ozone increases with increasing ozone gas concentration and decreasing water temperature. The degree of surface modification was estimated by X-ray photoelectron spectroscopy and cation dye-affinity (K/S). The effect on polyester fabrics increased with a higher concentration of ozone and lower temperature, partly also because ozone degrades in hot water. The apparent activation energy of the reaction between dissolved ozone and the polyester surface is constant and independent of the dissolved ozone concentration. The localized heating of the polyester surface enhances the modification efficiency exceptionally.View full abstractDownload PDF (783K) -
Yasuo GOTOH, Yuki NEIWA, Yu HIRASAWA, Sijun XU, Jiangchao SONG, Hideak ...2016 Volume 73 Issue 4 Pages 347-353
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: May 24, 2016JOURNAL FREE ACCESSWe investigated the influence of of graphene oxide (GO) on the tensile properties of high-strength and high-modulus poly(vinyl alcohol) (PVA) fibers. The fibers were prepared by gel-spinning of PVA/dimethyl sulfoxide solutions containing a small amount (0.5 wt%) of GO and hot drawing. It was found that GO in the PVA matrix was well dispersed via hydrogen bonds, and was oriented with respect to the fiber axis. For the PVA fiber with a strength of over 2 GPa and a modulus of 40–50 GPa, addition of GO brought about a small decrease in strength and elongation at break and increase in Young’s modulus by 3–5 GPa. We explain the change of the tensile properties by GO addition through the strength relationship between shear stress and adhesion force acting at the PVA-GO interface. Addition of GO increases not the tensile strength but the Young’s modulus, improving the performance of PVA fibers.View full abstractDownload PDF (812K) -
Tetsuya DANNO, Emi HASEGAWA, Yuichi KONOSU, Mie MINAGAWA, Masatoshi TO ...2016 Volume 73 Issue 4 Pages 354-360
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: July 08, 2016JOURNAL FREE ACCESSLiquid crystal polymer (LCP) nanofibers were prepared by electrospinning from hydroxypropyl cellulose (HPC) aqueous solutions at various concentrations and temperatures. At room temperature, the HPC aqueous solution exhibited an isotropic-cholesteric phase transition at 42 wt%. By increasing temperature, the solutions showed a biphasic structure—a mixture of LC and isotropic phases at 35–50°C. Smooth and bead-free HPC fibers were obtained by electrospinning from all, the isotropic, cholesteric, and biphasic solutions. In all the electrospun fibers, HPC molecules oriented parallel to the fiber axis with a spacing of 11 Å. In addition, the molecular orientation parameter along the fiber axis showed high values between 0.80 and 0.86 regardless of the difference in the structure of the aqueous solution.View full abstractDownload PDF (816K)
Notes
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Yuko IWAMI, Shiori TOMITAKA, Masanori NATA, Seiji UJIIE2016 Volume 73 Issue 4 Pages 361-365
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: May 19, 2016JOURNAL FREE ACCESSNovel thermotropic liquid-crystalline cellulose derivatives were synthesized by the addition reaction of hydroxypropylcellulose with isocyanate. The liquid-crystalline cellulose derivatives exhibited columnar mesophases on heating and cooling. The cellulose derivatives formed a water-absorbing resin and their resinous gel films showed water-absorbency and stability with time. The resin plates of the cellulose derivatives were obtained by a hot press process at liquid-crystalline temperatures. They showed a tensile strength that was stronger than that of polypropylene.View full abstractDownload PDF (551K) -
Estimation of the Core-Shell Formation Efficiency of Electrospun Collagen/Polylactic Acid NanofibersArata KATO, Shin-ichiro SUYE, Satoshi FUJITA2016 Volume 73 Issue 4 Pages 366-369
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: May 17, 2016JOURNAL FREE ACCESSNanofibers are expected to become useful as medical materials including tissue engineering scaffolds, wound dressings, and carriers for drug delivery systems (DDS), because of their high specific surface area, porosity, anisotropy and the molecular order. Especially, the potential of core-shell nanofibers, that are composed of two types of materials for core and shell, are drawing attention to DDS materials because it is possible to suppress the diffusion of the drug from the core material through the shell material to realize a more precise controlled release. To use core-shell fibers in DDSs, the detailed characterization of the structure, including core-shell ratio, the surface area, and the core-shell formation efficiency is required. However, the structural analysis of individual fibers has not yet been fully carried out, although bulk properties have been well examined. Here, to obtain key structural information for DDS materials, we estimated the efficiency of polymer incorporation into complete core-shell fibers from cross-sectional images of the core-shell nanofibers by SEM observation.View full abstractDownload PDF (589K)
Regular Topics
Comprehensive Papers
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Influence of Interfacial Adhesion on Fatigue Resistance of Polypropylene/Calcium Carbonate CompositeKouichi KOUKA, Shigeki HIKASA2016 Volume 73 Issue 4 Pages 370-376
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: June 03, 2016JOURNAL FREE ACCESSWe investigated the influence of both interfacial adhesion and filler diameter on fatigue resistance of polypropylene (PP)/calcium carbonate (CaCO3) composites. Maleic anhydride grafted Polypropylene (PP-MAH) was used as compatibilizer for interfacial adhesion. Several kinds of CaCO3 having mean diameters from 0.9 µm to 20 µm were used as fillers. The fatigue lifetime increases by using an interfacial adhesive. Also, the fatigue lifetime of the composite including small diameter filler was larger than that of the composite including large diameter filler. The mechanism of fatigue fracture was evaluated by normalized stress/life-time (S-N) diagrams. The fatigue fracture according to adding a filler with a diameter of 20 µm and 0.9 µm was not changed by interfacial adhesion. However, the fatigue fracture of 6 µm and 3 µm fillers was changed by interfacial adhesion.View full abstractDownload PDF (947K)
Original Papers
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Shoya IMAMOTO, Hiroaki KOUZAI2016 Volume 73 Issue 4 Pages 377-383
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: June 28, 2016JOURNAL FREE ACCESSIn this study, we synthesized phenothiazine-based polymers having polar functional group at the chain ends. We then carried out hybridization of the obtained polymers with silica. The weight average molecular weight (Mw) of the obtained polymers were 4000~5700. Thus, there were soluble in organic solvents such as chloroform and THF. The polymers were thermally stable and showed a 10% thermogravimetric loss around 280°C. Fluorescence spectrum of poly[10-(2-ethylhexyl)phenothiazinyl-alt-phenylene] (P1) in THF showed peaks at 490 nm an 520 nm, supporting light blue emission. In addition, a similar emission was confirmed from solid-state P1. In the case of a P1/SiO2 hybrid, the peak of photoluminescence was observed at 480 nm to emit blue light. Thermal stability and weather ability of the P1/SiO2 were also investigated.View full abstractDownload PDF (744K)
Notes
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Wataru ITOU, Yuki IDA, Tokio HAGIWARA2016 Volume 73 Issue 4 Pages 384-387
Published: July 25, 2016
Released on J-STAGE: July 25, 2016
Advance online publication: May 23, 2016JOURNAL FREE ACCESSFour N-(4-halogenophenyl)maleimides (4-Hal-PMI) monomers, N-(4-fluorophenyl)maleimide (4FPMI), N-(4-chlorophenyl)maleimide (4CPMI), N-(4-bromophenyl)maleimide (4BPMI), and N-(4-iodophenyl)maleimide (4IPMI) were synthesized and obtained as yellow needle crystals. A positive relationship between the Hammett’s substituent constants (σ) and 1H NMR chemical shifts (δ) of the vinylene protons of all 4-Hal-PMI were observed. Each anionic polymerization of 4-Hal-PMI with lithium tert- butoxide took place at the vinylene moieties and gave the correspondent poly(4-Hal-PMI) in 27–50% yields after 24 h at －60°C. A negative relationship was seen between the yields of poly(4-Hal-PMI) and the Hammett’s σ of each substituent of 4-Hal-PMI.View full abstractDownload PDF (410K)
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