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Volume 48, Issue 6
Displaying 1-9 of 9 articles from this issue
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Makoto HOSHINO, Jin Cherl SONG, Takashi YOSHIDA, Toshiyuki URYU1991 Volume 48 Issue 6 Pages 341-346
Published: June 25, 1991
Released on J-STAGE: November 22, 2010
JOURNAL FREE ACCESSThe chemical structure of a keratin hydrolysate-Fe (II) ion complex, which is used as fire-extinguishing foam for petroleum fires, was studied by means of 13C NMR spectroscopy. Lower-field shift of three peaks in the 13C NMR spectrum of keratin hydroly-sate was observed after adding Fe (II) salt to keratin hydrolysate solution in deuterium oxide. It was assumed that the coordination of Fe (II) ion with the protein occurred at pendant amino groups of amino acid residues in the keratin hydrolysate. To analyze the structure of the protein-Fe (II) complex, poly-L-ornithine and poly-L-lysine were used as model polypeptides. Reaction of polyornithine with Fe (II) salt gave the peak broadening and lower-field shift in the 13C spectrum, suggesting that the coordination of Fe (II) ion to pendant amino groups of the protein might occur. The Cu (II) ion also formed a complex with poly-L-ornithine. Although no peak shift of poly-L-lysine was observed due to the addition of Fe (II) salt, the addition of Cu (II) salt to poly-L-lysine solution caused strong peak broadening at the two peaks (Cδ and Cε). These results show that polyornitine and polylysine have an ability to form metal ion complexes. They suggest that such amino acid residues as ornithine and lysine might form a Fe (II) complex in the keratin hydrolysate fire-extinguisher.View full abstractDownload PDF (925K) -
Kenichiro SUETSUGU1991 Volume 48 Issue 6 Pages 347-351
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe tensile strength of the composite in which the adhesive condition between polymer and filler was insufficient was investigated theoretically on the assumption that all fibers were arranged in one direction Parallel to each other. The variation of the ratio Hs/Hs (0) (Hs, conductive function, Hs (0); concentration c=0wt%) according to sorts and concentration of filler-surface modifiers was investigated for composite materials such as polycarbonate/glass fibers. Conductive conditions become better according to the increase of the concentration of filler-surface modifier, and finally converge to be constant. Moreover, conductivity of graft agent tends to be higher than that of conventional silane filler-surface modifier. These results revealed that the conductivity Hs of the load on fibers through the matrix was a significant factor to describe inssufficient adhesive conditions of polymer/filler.View full abstractDownload PDF (966K) -
Kenichiro SUETSUGU1991 Volume 48 Issue 6 Pages 353-357
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSIn the case of nylon RIM materials mixed with milled glass, mica, and glass flakes under nitrogen gas, flexural modulus was improved according to increases of weight percent and average aspect ratio; this was different in the case of the tensile strength of fiber reinforced RIM materials. Little difference was found between flexural modulus of molds products made by a low pressure treatment method and that of molds products made by the conventional method. The fiexural modulus was little influenced by adhesive conditions between polymer and filler. For the flexural modulus, when a load was put on the direction Perpendicular to the test pieces, not only extended load but also compressed load were created at both sides of the test piece. This compressed load was influenced by the adhesive condition of polymer/filler and did not show such a great difference between good adhesive condition and not good condition. Consequently, the flexural modulus of nylon RIM materials was litle influenced by the adhesive conditio of filler/polymer, and good flexural modulus could be obtained on condition that nylon RIM materials were mixed with filler under nitrogen gas.View full abstractDownload PDF (1034K) -
Tohru MARUNO, Kouzaburou NAKAMURA1991 Volume 48 Issue 6 Pages 359-363
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSNovel fluorine-containing epoxyacrylate resins and epoxymethacrylate resins have been synthesized from two epoxy resins, diglycidylether of bis (1, 1, 1, 3, 3, 3-hexafluoro-2-hydroxyisopropyl) cyclohexane and diglycidylether of 4, 4′-bis (1, 1, 1, 3, 3, 3-hexafluoro-2-hydroxyisopropyl) diphenylether. Four synthesized resins can be cured by UV-irradiation, they show extremely low refractive indices of 1.428-1.495 due to their high fluorine contents of 29-34wt%. Cured resins are highly transparent to wavelengths from 0.5 to 1.6μm; they demonstrate high adhesive strengths to quartz glass, more than 85kgf/cmcm2. These resins have a particular utility for the formulation of optically transparent adhesives, since they improve matching of the refractive index with that of optical glass. The adhesive composition provides very high return loss more than 40dB at the joints of optical fibers.View full abstractDownload PDF (867K) -
Kuniyoshi ITOYAMA1991 Volume 48 Issue 6 Pages 365-371
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe partition function for a folded- crystalline chain incorporated into lamellar crystals is formulated as a function of chain-flexibility parameter by the generating function method. The correlated-walk problem of enumerating statistical weights for configurations of a polymer chain confined by one wall is solved for the body-centered-cubic lattice as generalization of the random-walk model treated by Roe. According to the results calculated for the “switch-board” model (SB-M) of loop formation, the chemical potential of the crystalline chain is less dependent on chain flexibility. Furthermore, a simplified three-phase model, in which polymer chains are preferentially stretched perpendicular to the lamellar surface in the interface region between the crystalline and amorphous regions, is used to avoid chain overcrowding in the amorphous region of SB-M. The results calculated for the three-phase model show that the crystalline chain becomes thermodynamically less stable with decreasing chain stiffness. Additionally, in the vicinity of melting temperature the sizes of loops and cilia grow much larger due to a substantial increase in the interface thickness.View full abstractDownload PDF (1255K) -
Yuko TANAKA, Katsutosi TANAKA1991 Volume 48 Issue 6 Pages 373-379
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSDynamic mechanical properties and thermomechanical properties of epoxy resin composites filled with silica microballoons were studied by varying degas time and mixing procedure of components and fillers. The glass transition temperature (Tg) of the composites was high when the resin and the filler were mixed prior to the addition of curing agent. But Tg of the composites was lower when the resin and the curing agent were mixed prior to the addition of the filler. The Tg decreased with further degassing. These facts indicates the preferential absorption of curing agent on fillers. The storage modulus depends on the surface area of the filler corresponding to the pores with radius larger than 3.75nm. Tg, impact strength, flexural strength and linear thermal expansion coefficient of composites filled with silica microballoons pretreated with silane coupling agent (SC) were higher than those of composites filled with untreated fillers. This result indicates that the SC pretreatment might prevent the absorption of curing agent on the filler.View full abstractDownload PDF (3021K) -
Yukihiro NAKANO, Hideki YAMANE, Yoshiharu KIMURA, Toshio KITAO1991 Volume 48 Issue 6 Pages 381-389
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSLiquid crystalline copolyester (LC) comprising 80mol% p-hydroxybezoic acid and 20mol% poly (ethylene terephthalate) (PET) as a minor component was blended with bisphenol A poly (carbonate) (PC) as the major component. Morphological studies revealed that the dispersion state of LCP component in PC matrix, in terms of the average size of LCP component, improved with increasing molecular weight of PC and with increasing revolution speed of the rotor of the kneeder used. The shape of the LCP component in the melt spun blend fibers depended on the initial dispersion state of as blended samples. Both tensile modulus and strength of the blend fibers increased linearly with increasing aspect ratio of LCP component. The reinforcement of PC matrix by LCP component was clearly achieved in tensile modulus. However, because of the lack of sufficient adhesion between LCP and PC, the tensile strength of the blend fibers was lower than that of PC fibers.View full abstractDownload PDF (4360K) -
Kenichiro SUETSUGU1991 Volume 48 Issue 6 Pages 391-394
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe relation between tensile modulus and flexural modulus was investigated for many composite materials, snch as polycarbonate/glass fiber (GF), polypropylene/GF, and polyamide/GF. In materials of inlection moldings, tensile modulus and flexural modulus showed an almost linear relation, except for a few materials whose matrices were crystalline or whose adhesive conditions betweeen polymer and filler were not good. For this reason, great differences between the two were not found. The reason why in some exceptional cases tensile modulus and flexural modulus tend to slip from the linear relation could be that the tensile modulus had tendency to be influenced by the adhesive conditions of pdymer/filler and thus the tensile modulus became lower because of bad adhesive conditions.View full abstractDownload PDF (659K) -
Takashi KATO, Atsunori KOSHIRAI, Toshiyuki URYU1991 Volume 48 Issue 6 Pages 395-398
Published: June 25, 1991
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSA thermotropic aromatic polyester based on phenylhydroquinone and 1, 6-diphenoxy-4, 4′-dicarboxylic acid was prepared by melt-polycondensation. The polyester showed a nematic phase from 155 to 180°C. Injection-molded samples of the polyester at nematic and isotropic states gave tensile strengths of 1.1×103 and 0.8×103kgf/cmcm2, respectively. SEM observations indicated that the polyester was anisotropically oriented when it was injection-molded at a nematic state. No orientation was observed for the injection-molded sample at an isotropic state. These results suggest that it is possible to control the anisotropy of mechanical properties of thermotropic polyesters with low melting and isotropization temperatures.View full abstractDownload PDF (2233K)
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