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Volume 54, Issue 5
Displaying 1-14 of 14 articles from this issue
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Dong-Jin Lee, Toshiyuki Uryu1998 Volume 54 Issue 5 Pages 246-252
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThermotropic poly (imide-urethane) PIUnTp's and PIUnTm's (n: the number of methylene unit, 5, 6, 8, and 11; p: para-type unit; m: meta-type unit) containing no mesogenic unit were synthesized by polyaddition of N, N'-bis [2-methyl-4- (ω-hydroxyalkoxy) phenyl]- 2, 3, 6, 7-naphthalene dicarboximides (BMNDIn) with a para-type 2, 5- or a meta-type 2, 4-tolylene diisocyanate (2, 5- or 2, 4-TDI). The poly (imide-urethane) PIUnTp's and PIUnTm's showed liquid crystallinity in the cooling stage under shearing. For example, a para-type poly (imide-urethane) PIU6Tp exhibited liquid crystallinity in the temperature range from 247°C to 226°C and a meta-type poly (imide-urethane) PIU6Tm exhibited liquid crystallinity in the temperature range from 242°C to 221°C in the cooling stage. The liquid crystallinity was examined by DSC measurement, polarized optical microscope observation, and X-ray diffractometry.View full abstractDownload PDF (1053K) -
Kazutaka Itoh, Yuugo Uegaki, Kenji Okazaki, Sanro Tachibana1998 Volume 54 Issue 5 Pages 253-260
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSTreatment of the pulps prepared from non-woody plants, abaca and kenaf with two commercially available pectinases, pectinase PL _??_AMANO_??_ and Ultrazym containing CMC-ase, xylanase and β-glucosidase was conducted to investigate the effect of the pulp properties on the pectinases treatment. We found that large amounts of parenchyma cells in the both kenaf and abaca pulps were removed by the two pectinases treatments. Seventy to almost one hundred percent of the parenchyma cells could be removed from the both pulps by the 24 hours' treatment. However, the weights of the kenaf and abaca pulps treated with the pectinases were decreased by 4 to 28%, especially the loss of the weights was increased with increase in amounts of CMC-ase, β-gulucosidase and xylanase coexisted in the pectinases. The water retention values of the kenaf and abaca pulps were decreased by 28 to 80% by the treatment with pectinase PL _??_AMANO_??_. On the contrary, the values of the kenaf pulps were increased by 10 to 53% by the treatments with Ultrazym. The physical properties of the abaca pulps treated with pectinase PL _??_AMANO_??_ generally made little difference from those of the untreated pulps. However, the breaking length in the physical properties of the abaca pulps was improved by 5 to 36% by the treatment with the pectinase. The properties of the kenaf pulps treated with the pectinase were lowered in those of the untreated pulps.View full abstractDownload PDF (1635K) -
Tadakazu Miyata, Takeyuki Yachida, Toru Masuko1998 Volume 54 Issue 5 Pages 261-269
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSChanges of orientation and crystallinity in uniaxially drawn poly (L-lactide) (PLLA) films were studied by differential scanning calorimetry, x-ray diffractometry, optical and viscoelastic methods. After drawing amorphous PLLA films at 90°C in air, we observed that their crystallinity, orientation of crystallites, refractive index, and storage moduli at 30°C increased monotonically with increasing draw ratio (D. R.); however, these physical properties were saturated at D. R. of ca. 2.5. To draw the unoriented film brought about intermolecular crystallization of the PLLA chains effectively at 90°C. Most crystallites thus formed in the drawn films were found to be the a-form and oriented into the drawn direction to a saturated level at D. R.=2.5_??_3.0. Alternatively, when as-crystallized PLLA films were drawn at 150°C to about 10 times of the original length, they showed a unique x-ray fiber diagram where continuous scattering intensities imposed on the diffraction spots were located on three layer lines. Long period of the drawn film annealed at 170°C indicated a larger value than that of the as-drawn film.View full abstractDownload PDF (1684K) -
Sijia Min, Toshinobu Nakamura, Akira Teramoto, Koji Abe1998 Volume 54 Issue 5 Pages 270-276
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSIn this paper, the release and the permeation characteristics of model drugs of crosslinked porous silk fibroin gel (CPFG) and its solubility and degradability were investigated. CPFG was prepared by using ethylene glycol diglycidyl ether (EGDE) as a crosslinking agent. It was found that with an increase of pH of the bulk solution, the release rate of the a cationic compound from CPFG was lowered and that of an anionic one was quickened. However, the release rate of the non-ionic compound was independent witk pH of the solution. These release rates of the charged drugs were changed by modifying -COOH residues of fibroin. The permeation diffusion rate of the compounds in CPFG decreased with the decrease of pore size (the increase of the density) of CPFG. Moreover, The diffusion rate was also affected by an electrostatic interaction between compounds and CPFG. In neutral or weakly acidic solution, a small amount of fibroin was dissolved from CPFG, and the amount of dissolved fibroin increased in acidic or alkaline solution. CPFG can also be degraded by protease.View full abstractDownload PDF (1121K) -
Kiyohiro Inoue, Seigo O-oya, Mun-soo Lee, Shuuichi Akasaka, Shigeo Asa ...1998 Volume 54 Issue 5 Pages 277-284
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSThe characteristics of the alkaline degradation process and the mechanical properties of polyester blends of poly (L-lactic acid) (PLLA) and poly (butylene succinate) (PBSU) were studied. The blends were immiscible in the amorphous states from the DSC measurement results. The elongation of PLLA/PBSU blends were large (several hundred percent), however the elongation of PLLA was small (several percent). In regard to the weight decrease of alkaline hydrolysis tests, PLLA had the fastest rate of decrease and PBSU had the slowest rate of decrease. The degradation rate of PLLA/PBSU 75/25 blends and 50/50 blends were close to PLLA. A weight decrease was observed in the PLLA/PBSU 25/75 blends. The degradation rate can be adjusted by blending the PLLA in the PBSU. The results from the measurements of DSC and WAXD showed that the increase of degree of crystallinity was very limited. The characteristic globular cracks of the child (fractal) forms were observed in degraded pure PLLA by means of a scanning electron micrograph. The surfaces with the general unevenness were seen in degraded pure PBSU. The special structures (which were mixed hierarchically) were seen in the blends. Although PLLA/PBSU blends were immiscible, the blends had the structures which were hierarchical. It may contribute to the mechanical properties.View full abstractDownload PDF (2577K) -
Junzo Masamoto, Naoaki Yamasaki, Wataru Sakai, Takashi Itoh, Naoto Tsu ...1998 Volume 54 Issue 5 Pages 285-289
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSIn a previous report, we noted a new direct reaction between 1 mole of trioxane and 1 mole of ethylene oxide and the formation of a novel cyclic formal of 1, 3, 5, 7-tetraoxacyclononane. We have now determined a new reaction and novel cyclic compound from the reaction of trioxane and ethylene oxide. The novel cyclic compound was separated and collected using a micro-distillation apparatus and gas chromatographic method. Its chemical structure was confirmed using 1H-NMR, 13C-NMR, mass spectrum and elemental analysis. The new isolated novel cyclic compound was 1, 3, 5, 7, 10-pentaoxacyclododecane, which might be formed by the direct reaction of 1 mole of trioxane and 2 moles of ethylene oxide. In the commercial base acetal copolymer, which was produced by the copolymerization of trioxane and ethylene oxide, it is known that there is a consecutive two units sequence of ethylene oxide, and this consecutive 2 ethylene oxide unit sequence might be postulated to come from the ring opening-polymerization of the novel cyclic formal of 1, 3, 5, 7, 10-pentaoxacyclododecane.View full abstractDownload PDF (343K) -
Mariko Sato, Hiroko Hasegawa, Haruko Yamano, Tadashi Nakanishi, Toshin ...1998 Volume 54 Issue 5 Pages 290-292
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSA new apparatus for measuring the sweat rate, utilizing a capsule with two hygrosensors of electrostatic capacity type, was designed and constructed. In this apparatus, the net value of sweat rate was estimated from the difference between the indicates of the two hygrosensors equipped at the upstream and downstream sides for the sweat collection window of the capsule. The apparatus is able to detect a small amount of perspiration accurately, and sufficient to follow the rapid change of the sweating activity.View full abstractDownload PDF (217K) -
MASAKATSU OKUMURA1998 Volume 54 Issue 5 Pages P155-P159
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (958K) -
HIDEO SEKIYA1998 Volume 54 Issue 5 Pages P160-P165
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
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HIROYUKI NAGAI1998 Volume 54 Issue 5 Pages P166-P172
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
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MASAYUKI SATO1998 Volume 54 Issue 5 Pages P173-P176
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
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SACHIKO MATSUMURA1998 Volume 54 Issue 5 Pages P177-P184
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESS -
HARUTAKA TOYODA1998 Volume 54 Issue 5 Pages P185-P188
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
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MASAKO NIWA1998 Volume 54 Issue 5 Pages P189-P194
Published: May 10, 1998
Released on J-STAGE: June 30, 2008
JOURNAL FREE ACCESSDownload PDF (1322K)
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