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Volume 55, Issue 1
Displaying 1-12 of 12 articles from this issue
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Hoonsik Shin, Mitsuo Ueda1999 Volume 55 Issue 1 Pages 1-6
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSFixation of chitosan on cellulosic fabrics with using a cross-linking reaction of polycarboxylic acid has been investigated. Cotton fabrics that was cross-linked with polycarboxylic acid such as citric acid (CA) and butanetetracarboxylic acid (BTCA) showed to have appreciable amount of free carboxylic acid residues on the fabric that came from the polycarboxylic acid without participating the cross-linking reaction. Chitosan could be fixed on the fabric with good fastness to acid washing by padding and following curing process. Relatively high wrinkle recovery characteristics of the cross-linked and chitosan fixed fabric was obtained. The fixation of the chitosan on cotton fabric could also be done by the simpler process that consists of padding of mixture of polycarboxylic acid and chitosan onto untreated cotton fabric followed by high-temperature curing. With this process, simultaneous chitosan fixation could be achieved with the cross-linking reaction of polycarboxylic acid with cotton substrate. Intermolecular ester linkage formation by the polycarboxylic acid was suggested by the FTIR measurements.View full abstractDownload PDF (418K) -
Siripong Premjet, Akira Shimamoto, Yoshito Ohtani, Kazuhiko Sameshima1999 Volume 55 Issue 1 Pages 7-12
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSWe previously reported that the cellulose production by Acetobacter xylinum ATCC 10245 is greatly increased by the addition of lignosulfonate into the standard cultivation medium. This effect was shown to occur with various sources and bacterium strains. But the mechanism of the yield increase is not clear. In this report we examined the relationship between final pH of the media and the yield of cellulose with various types and concentrations of buffer to clarify the role of buffer components and the lignosulfonate on the bacterial cellulose production. The results showed that the intermediate acids, citric acid and succinic acid, in the TCA cycle presumably relating to the dissimilation system of cellulose played an important role on the cellulose synthesis, and the lignosulfonate strongly related to these reactions. Therefore, the role of cellulose dissimilation system in the cellulose synthesis should be further investigated.View full abstractDownload PDF (431K) -
Tadahiro Izumoto, Hideo Umeda, Shinichi Sakurai, Junzo Masamoto, Shunj ...1999 Volume 55 Issue 1 Pages 13-20
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSPolystyrene-block-polyethylenebutylene-block-polystyrene (SEBS) triblock copolymers are widely utilized as thermoplastic elastomers. In this study, solubilization of poly (phenylene ether) (PPE) into polystyrene (PS) microdomains was examined in order to improve the heat resistance of the SEBS triblock copolymers, where the PPE homopolymer has a higher glass transition temperature than PS and is generally known to be totally miscible with PS homopolymers with any composition. An ordinary solvent-cast method was employed for the sample preparation. As a result, macroscopic phase separation took place, although a small quantity of PPE was blended. The macroscopically phase-separated structures and microphase-separated structures were analyzed by the small-angle X-ray scattering technique and complementarily by the transmission electron microscopic observation. An appreciably broad interface between the macroscopically phase-separated domains was observed in SEBS/PPE solvent-cast samples. Based on the assumption that the cast solvent is more or less accumulated in the interface, the mechanism of forming such a broad interface is presented.View full abstractDownload PDF (3233K) -
Yutaka Ohkoshi, Hirohiko Shirai, Yasuo Gotoh, Masanobu Nagura1999 Volume 55 Issue 1 Pages 21-27
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe intrinsic birefringence value of Poly (L-lactic acid) was estimated experimentally for the drawn and annealed fiber, in which almost all of the crystals involved are the α-form. The value 0.030-0.033 was obtained using Stein's formula by substituting the results of structural analysis for highly drawn and annealed samples. The extrapolated value 0.030 was also obtained by assuming the affine deformation. On the other hand, as the intrinsic birefringence value of the α-form crystal, -0.013 was also obtained by summation of bond polarizability using crystal structure data. The experimental value is more believable because the contribution of convalent bond alone was included in the calculationView full abstractDownload PDF (473K) -
Daisuke Asahina, Yoshiharu Miyashita, Yoshiyuki Nishio1999 Volume 55 Issue 1 Pages 28-33
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSHydroxypropyl derivatives of chitosan with different degrees of substitution (DSs) were synthesized successfully via etherification of chitosan with propylene oxide. Phase behavior and liquid-crystalline characteristics of aqueous solutions of hydroxypropyl chitosan (HPCt) were studied by light absorption, polarized optical microscopy (POM), and small-angle light scattering. Aqueous solutions of a highly substituted HPCt (DS=3.25) were phase-separated and became turbid at an elevated temperature of >40°C. The observed cloud point was shifted to higher temperatures with increasing HPCt concentration in the range examined, i.e., 5-60wt%. The phase separation behavior of the aqueous HPCt solutions was affected appreciably by addition of inorganic salts thereinto. POM observations revealed that an optically anisotropic monophase prevailed in the concentrated solutions containing ≥50wt% HPCt (DS=3.25). Oriented HPCt films prepared from the concentrated solutions under shear, exhibited a so-called banded structure characteristic of sheared or elongated liquid-crystalline polymers.View full abstractDownload PDF (1358K) -
Minoru Kimura, Hiromi Uchimura, Keiichi Satoh, Atsushi Sawatari1999 Volume 55 Issue 1 Pages 34-38
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe quantitative relation between drying shrinkage and strain-to-failure of bleached softwood kraft pulpsheet was investigated. The amount of drying shrinkage was calculated by measuring the dimensional change of the sheet having various degrees of partial shrinkage restraint before and after drying. The calculation was made based on the fact that no shrinkage of wet sheet on the ferrotype plate occurred in the standard drying method. The amount of shrinkage taking place in the drying process was found to contribute quantitatively to an increase in strain-to-failure in the elongation test. It was also shown that a large amount of strain-to-failure of a freely dried or partially restrained sheet was due to the following two components: one resulting from a structural feature originally introduced into the fiber or sheet network by beating, the other resulting from the sheet shrinkage introduced during drying. Acoustic emission from all the paper sheets was detected primarily at the final stage of the elongation test, regardless of the degree of drying shrinkage of the samples. This result indicates that no critical structural breakage causing emission of elastic wave occurred in the plastic deformation due to drying shrinkage.View full abstractDownload PDF (326K) -
YOSHIHISA KANO, SABURO AKIYAMA1999 Volume 55 Issue 1 Pages P2-P8
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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SHUICHI NOJIMA1999 Volume 55 Issue 1 Pages P9-P13
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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MAMORU OKADA1999 Volume 55 Issue 1 Pages P14-P18
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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GISELA BUSCHELE-DILLER, [in Japanese]1999 Volume 55 Issue 1 Pages P20-P25
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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RYOHEI YAMAMOTO1999 Volume 55 Issue 1 Pages P26-P29
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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TOSHIHIRO HIRAI1999 Volume 55 Issue 1 Pages P30-P35
Published: January 10, 1999
Released on J-STAGE: November 28, 2008
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