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Volume 48, Issue 3
Displaying 1-15 of 15 articles from this issue
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Katsufumi Tanaka, Kiyohito Koyama1992 Volume 48 Issue 3 Pages 105-111
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSMelt spinning behavior of polyimide filaments and their mechanical properties at temperature range up to 400°C were investigated. The region of elongational deformation was narrow and was less than 2cm from the spinneret under the spinning condition at the extruded temperature of 404°C, the extrusion rate of 1.88×10-3cm3/s and the take-up velocity of 47.2cm/s. Elongational viscosity of the deformation region ranged from 105 to 107 poise. Activation energy for the elongational flow was calculated to 80kcal/mol and it was much larger than that of a linear type PPS. The narrow deformation region, and the large elongational viscosity and activation energy were discussed with molecular rigidity of the polyimide. Temperature dependence of dynamic storage modulus (E′) of the annealed filaments taken up above 47.1cm/s showed plateau and terminal zone at temperatures higher than the primary dispersion temperature of about 240°C. E′ in the plateau zone and the temperature at the beginning of the terminal zone of the filaments increased with increasing the take-up velocity. Maximum value of E′ at 325°C was 2×109 dyn/cm2. It was indicated that the different features of E′ above the primary dispersion temperature were associated with not only crystallinity but also molecular orientation in the filaments.View full abstractDownload PDF (823K) -
Kazutaka Itoh, Sanro Tachibana, Masashi Sumimoto1992 Volume 48 Issue 3 Pages 112-119
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSTreatment of both formaldehyde and creosol dispersed in linter pulp by either CBM and VBM furnished three condensation products I_??_III. Addition of creosol to pine chips, “rough pulps” (Asplund pulps), and the mill-made “1R-pulps” (TMP), followed by the treatment with laboratory refiner also afforded products I_??_III. Effect of pH of 4.0, 7.0, and 10.0 on the yields of condensation products I_??_III was also examined for “rough pulps” and “1R-pulps” by refiner treatment. The higher the pH value, the yields of reaction products I and II increased.View full abstractDownload PDF (473K) -
Kyohei Joko, Joichi Koga1992 Volume 48 Issue 3 Pages 120-126
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe liquid retention properties of wool fibers were investigated for those structurally modified by chemical and mechanical processes, such as treating with solvents and enzyme, heating in 8.0M LiBr solution and stretching in steam.
The extraction of nonkeratinous proteins with organic solvents and pronase was found to cause an increase in the liquid retension of wool fiber. Particularly, the removal of nonkeratinous proteins had marked effects on the retractive forces opposing the swelling pressure of the liquid in the cell membrane complex.
The supercontracted wools in which the original oriented α-structure was transformed to disoriented β-structure in the microfibril, had high liquid retension values at pH2 and 8, distant from the iso-electric point, pH5, whereas the stretched wools in which the oriented β-structure was effected, was little affected in the liquid retention throughout the pH range examined. These results suggest that the extent of the liquid retention of wool is dependent not on the secondary structure of the microfibrillar peptide chains, but on the orientation of the peptide chains which is closely associated with the retractive forces opposing the swelling pressure of liquid in the microfibril.View full abstractDownload PDF (469K) -
Masanobu Nagura, Yasuhiro Arai, Yutaka Ohkoshi1992 Volume 48 Issue 3 Pages 127-132
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSHighly elastic and high water-content hydrogels were prepared by coagulation of concentrated aqueous solutions of poly (vinyl alcohol) (PVA) and poly (allyl amine) (PAlAm) blends in an autoclave at 2 atm and at 120°C, followed by dehydration in methanol and re-swelling in water. The elastic moduli of the hydrogels increased with increasing PAlAm content and were higher than those of the PVA hydrogels obtained by repeated freezing and thawing. This was explained based on the presence of rigid phase due to the formation of polymer complex between PVA and PAlAm. The water enclosed in the network had lower mobility than the free water.View full abstractDownload PDF (837K) -
Tokuju Goto, Tomiji Wakita, Toshio Nakanishi, Yasushi Ohta1992 Volume 48 Issue 3 Pages 133-137
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDewaxing of gray cotton fabric is an important operation in the dyeing process, Instead of the conventional wet scouring process, oxygen low temperature plasma treatment was applied to gray cotton fabric. The low temperature plasma treatment was useful technic to remove the surface cotton wax. In order to confirm the practical effect, two kinds of cotton fabric which were treated with the conventional scouring and the low temperature plasma processes, were processed subsequently bleaching, mercerizing, dyeing, and finishing under the same conditions. The qualities of both fabrics were almost the same, but it seems likely that the consumptions of chemicals, water, and energy by low temperature plasma process are much less than those of conventional one. The scouring time by conventional process was reduced to one twentyth by the low temperature plasma process.View full abstractDownload PDF (339K) -
Takuma Jinda1992 Volume 48 Issue 3 Pages 138-140
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSAromatic polyether-esters were synthesized from hydroxy acid-type monomers, in order to obtain melt-processable, crystalline aromatic polymers. Poly (oxy-1, 4-phenyleneoxy-1, 3-phenylenecarbonyl) had a melting temperature of 292°C and poly (oxy-1, 4-phenyleneoxy-1, 4-phenyleneoxy-1, 4-phenylenecarbonyl) had those of 307, 326°C (double peaks). Both polymers could be melt-spun to yield fibers having moderate tensile properties and fairly good heat durability at 220°C.View full abstractDownload PDF (138K) -
Zuglul Haider Ayub, Kiyoshi Hirabayashi, Mitsuo Arai1992 Volume 48 Issue 3 Pages 141-144
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSAqueous silk fibroin gelled when it was kept for a required time under suitable conditions. The gelation time and the physical properties of fibroin gel could be controlled by adjusting pH and concentration of the silk fibroin solution. Gelation occurred when the electrostatic repulsion between the macromolecules was sufficiently reduced near and at the isoelectric point of silk fibroin (pI=3.8-3.9). The strength of the gel at the isoelectric point was weak due to an insufficient formation of a network structure. Gel strength and gelling rate were greatly dependent on pH and concentration of the silk fibroin solution. The formation of network structure depended on the amount of β-structure developed in the gel.View full abstractDownload PDF (642K) -
SOICHI TAKAGI1992 Volume 48 Issue 3 Pages P93-P98
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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KENGO OHASHI1992 Volume 48 Issue 3 Pages P99-P106
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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SEIICHIRO TOMIZAWA1992 Volume 48 Issue 3 Pages P107-P115
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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KENICHI TERAGUCHI1992 Volume 48 Issue 3 Pages P116-P119
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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SATORU ITOH1992 Volume 48 Issue 3 Pages P120-P125
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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MAMORU SHIMAKURA1992 Volume 48 Issue 3 Pages P126-P133
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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TOSHIFUMI MORIHASHI1992 Volume 48 Issue 3 Pages P134-P139
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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HIDEO MAEDA, SHIGERIU OKAMOTO1992 Volume 48 Issue 3 Pages P140-P144
Published: March 10, 1992
Released on J-STAGE: November 28, 2008
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