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Volume 37, Issue 7
Displaying 1-10 of 10 articles from this issue
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TATSU KAMBARA1981 Volume 37 Issue 7 Pages P238-P242
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
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YOSHIHITO OSADA1981 Volume 37 Issue 7 Pages P243-P251
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
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MASAKATSU OHGUCHI1981 Volume 37 Issue 7 Pages P252-P259
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
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KOHICHI NAKAMURA1981 Volume 37 Issue 7 Pages P260-P267
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
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Osamu Sangen, Hiroyuki Yokote, Hidehiko Nakano, Yoshitake Yamamoto1981 Volume 37 Issue 7 Pages T265-T272
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDynamic mechanical properties of segmented polyester-ether elastomers were determined by the viscoelastic spectroscopy.
Poly (ethyleneterephthalate) [T] and poly (ethyleneterephthalate-coisophthalate) [T/iPh] were used as the hard segments, while poly (ethyleneglycol) [E], poly (tetramethyleneglycol) [G] and their blended polyethers [E/G] as the soft segments.
Temperature dependence of elastomers composed of varying species of polyether as the soft segment on the dynamic modulus E′ and on the loss tangent (tan δ) was discussed. Effects of variations in the soft segment concentration and in its molecular weight on E′ and tan δ were also investigated.
A single loss peak due to the glass transition occurring in the non-crystalline phase consisting of a mixture of soft and hard segments was observed in T-E elastomers because of good compatibility of E with the hard segment. While, for T-G, especially in the case of hard-soft weight ratio was 50:50, two broad and weak peaks were observed separately in high and low temperature regions, indicating the improvement of the phase segregation between hard and soft segments.
The decrease in the loss peak area and the rise of the dynamic modulus in transition region suggested the crystallization of the soft segment of molecular weight 1500 or above.
Incorporation of iPh sequences in T-E elastomer improved the mixing of extended hard segment with the soft segment phase, which enhances the interaction between soft and hard segments.View full abstractDownload PDF (513K) -
Hiroshi Sakabe, Takeaki Miyamoto, Hiroshi Inagaki1981 Volume 37 Issue 7 Pages T273-T278
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSStructural changes in cast films of α-helical protein fraction isolated from reduced and S-carboxymethylated wool keratin (SCMKA) were investigated by X-ray diffraction. Two types of SCMKA films were prepared from the aqueous and formic acid solutions. Stretching of the films was successfully performed up to about 300% extension in 70% aqueous ethyl alcohol. It was found that (i) in addition to α-helical structure, the film cast from the formic acid solution contained partly β-structure, (ii) stretching up to 100% caused only the orientation effect of coiled-coil α-helical structure in both types of the cast films and (iii) at 200% extension, the oriented β-structure appeared in the films. The results were discussed in relation of the stress-elongation curves of SCMKA films in aqueous alcohol solutions.
The formation of β-structure was also accelerated by heating the films in steam, and the oriented films were obtained by stretching in steam to about 300% extension. On the other hand, when heated in vacuo, both types of SCMKA films showed no change in the X-ray diffraction patterns at temperatures up to 100°C, suggesting that water molecules may play an important role on the β-structure formation by heating. If the heating was carried out at 200°C for 3h in vacuo, the 5.1 Å reflection of coiled-coil α-helical structure vanished completely, while the 4.7 Å reflection characteristic of β-structure remained unchanged, indicating that the degradation temperatures of the two crystalline forms are different.View full abstractDownload PDF (2755K) -
Takuma Jinda, Takashi Kawai1981 Volume 37 Issue 7 Pages T279-T283
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSSeveral random copolyamides were synthesized from chloro-p-phenylenediamine, terephthaloyl chloride and other comonomers, using N-methylpyrrolidinone (NMP) as polymerization solvent. The copolyamides were wet-spun and heat-drawn. Only copolymers with 4, 4′-diaminodiphenylether or 1, 4-bis (p-aminophenoxy) benzene (each 30_??_40mole%) yielded fibers having a tenacity of 20g/d or more. Initial moduli of these fibers were 430_??_570g/d depending on the comonomer content. Another random copolymers composed of p-phenylene (35_??_45mole%)-, chloro-p-phenylene (20_??_35mole%) and 4, 4′-oxydiphenylene (30_??_40mole%) terephthalamide were soluble in NMP and they also gave fibers with similar high tenacity and initial modulus. Flex fatigue endurances of these fibers were somewhat superior to that of Kevlar®, but their tenacities retained at elevated temperatures were rather inferior.View full abstractDownload PDF (363K) -
Haruo Sanuki, Takeshi Shikama1981 Volume 37 Issue 7 Pages T284-T289
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSBlended assemblies of two different fibers were prepared. One of the two fibers belongs to a group of fibers, which absorb water well as single assemblies, e. g. cotton, rayon, and acrylic. The other belongs to a group of fibers, which hardly absorb water as single assemblies, e. g. wool, polyester, and polypropylene. In this report, cotton/polyester, rayon/polypropylene, and acrylic/wool blended assemblies were used. Dependences of wetting behavior of these blended assemblies on the blended ratio and the porosity were discussed.
The experimental procedures are as follows. Sample assemblies suspended from a strain gauge were immersed into water. Apparent weight of the sample assemblies in water were followed by the strain gauge as a function of elapsed time and the relations between retained air index (Va/Vc) and the time were obtained.
As a result of this study, each combination of fibers showed the characteristic wetting behavior. Since blended assemblies of acrylic with wool gave a result extremely different from the others, the wetting behavior of blended assemblies of rayon with wool was also measured to understand the wetting behavior of blended assemblies of acrylic with wool.View full abstractDownload PDF (513K) -
Aspergillus niger FERM J-1 AND Cladosporium cladosporioides FERM J-8Mutsuko Sato1981 Volume 37 Issue 7 Pages T290-T300
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDeterioration of polyurethane yarn was investigated with crude enzyme solution of fungi.
Two types of polyurethane yarns including ether type only or ester type mainly in the part of soft structure were tested. Two fungi, Aspergillus niger FERM J-1 and Cladosporium cladosporioides FERM J-8 were employed. The test pieces of yarns were immersed in the enzyme solutions from the fungi at given pH (3.5, 4.0, or 6.5). The mixture was shaken at 30°C for two weeks. The incubated yarns were observed by scanning electron micrography and some physical properties of the yarns were examined. Furthermore, the chemical changes of the yarns and the liberations of carboxyl group and ammonia were measured.
The tensile strength, viscoelasticity and extension behavior were remarkably changed. On the enzymatic digestion, various types of degradation were caused by the hydrolysis of several different type bonds in these polymers. Protease and esterase activities were in Asp. niger and Clad. cladosporioides. Urease was only detected in Asp. niger. These enzymes were inducible enzymes. Hydrolysis took place with enzymes of endo type.View full abstractDownload PDF (1725K) -
Koushi Fukunishi, Yasuhiko Hirose, Nobukazu Takahashi, Mototeru Nomura1981 Volume 37 Issue 7 Pages T301-T306
Published: July 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSSolvent dyeing of nylon 6 with 18-crown-6 complexed orange II was studied. Successfully isolated crown ether-dye complex was proved to be 1:1 complex [I] of Orange II (K) and 18-crown-6. Equilibrium sorption of the complexed dye (K) by nylon 6 from perchloroethylene, chloroform, and acetonitrile shows apparently Langumuir type isotherm both in the absence and presence of chloroacetic acid. Such dyeing phenomena were interpreted in terms of the ionic interaction between nylon 6 and the complexed dye in the aprotic solvents. The presence of chloroacetic acid in the complexed dyeing accelerates the rate of dyeing and changes the endothermic sorption into the exothermic one. When the dye is absorbed on the fiber, [I] decomposes to release free crown ether into solution.View full abstractDownload PDF (389K)
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