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Predecessor
Volume 51, Issue 2
Displaying 1-12 of 12 articles from this issue
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Takahiro NIWA, Satoru HASEGAWA, Jun MIZUKAMI, Hideo SAITO, Sadao HIBI1994 Volume 51 Issue 2 Pages 77-85
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPoly (ethylene terephthalate) films produced by rolling at a draw ratio 2.5×1.0 were stretched three times by off-axis angle re-drawing where constant deformation was given for thickness direction in the film, and X-ray pole figures of films were obtained. The crystalline orientation distribution function was applied to obtain the orientation distribution of each diffracted plane nomal for the rolled and off-axis angle re-drawn films. The calculations were compared with the measured pole figures.View full abstractDownload PDF (1310K) -
Masamitsu MIYA, Toshiharu HAMADA, Tomoo SHIOMI, Kiyokazu IMAI1994 Volume 51 Issue 2 Pages 87-92
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSPoly (vinyl alcohol) (PVA) gel membranes were prepared by UV irradiation to a mixture of PVA, dextran, and sensitizer, followed by removal of dextran by hydrolysis. Dextrans with various molecular weights were used to control the lattice size of the gel network. The lattice size of the membrane was estimated from the swelling measurements to depend on the molecular weight and concentration of dextran. The PVA membrane with a controlled lattice size was cationized by aminoacetalization with 2, 2-diethoxyethylamine. The charged membrane thus prepared was supplied to measurements of amino acid permeability. In consequence, permeability of amino acids depended on the lattice size of the membrane and the molecular weight of amino acids as well as the pH values of the solutions. This suggests that amino acids may be separated owing to the differences in the molecular weight and charge through the charged PVA membrane with a controlled lattice size.View full abstractDownload PDF (1092K) -
Kazuyuki KUWANO, Yonetoshi YAMAZAKI, Shinichi OTSUBO, Shinji HASEGAWA, ...1994 Volume 51 Issue 2 Pages 93-98
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effect of thixotropic agents in paints was studied using a rheometer which makes possible instant changes of the shear rate from a high value to a low value. The viscoelastic properties of two kinds of paints, containing different kinds of thixotropic agents, were studied in comparison with the properties of a paint which does not contain any thixotropic agent. From shear rate dependences of steady shear viscosity and apparent steady-state compliance, it was confirmed that a structure is formed in the paints at low shear rates, but destroyed at high shear rates. The structure once destroyed requires several minutes for recovery. The effect of thixotropic agents in paints should be carefully reconsidered.View full abstractDownload PDF (1006K) -
Hideo HAYASHI, Masa-aki KAKIMOTO, Yoshio IMAI1994 Volume 51 Issue 2 Pages 99-106
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effect of molecular weight of poly [N, N′- (oxydi-p-phenylene) isophthalamide] (aramid) on the properties of poly (ether sulfone) (PES) /aramid polymerization blended and solution blended films were investigated. The polymerization blended films were prepared by the polycondensation of N, N′-bis (trimethylsilyl) -substituted bis (4-aminophenyl) ether with isophtaloyl chloride in the PES solution in NMP, and the resulting blend solutions were directly cast into films. The compatibility of the polymerization blended films was not affected by molecular weight of the aramid over the inherent viscosity range of 0.5-2.7dl/g. Melecular weight of the aramid had no influence on the tensile modulus or tensile strength of the polymerization blended films because of their homogeneous merphology, whereas the properties of the solution blended films reduced at low molecular weight level of the aramid for the heterogeneous morphology. The elongation at break of the polymerization blended films from the aramid with moderate to high molecular weights was about 90%, indicative of tough and ductile films.View full abstractDownload PDF (1830K) -
Masae TAKAHASHI, Masako OOKUBO1994 Volume 51 Issue 2 Pages 107-113
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSCellulose III (Cell III) and Cell IV were prepared from Cell I and Cell II, and the effects of starting cellulose materials on the transition between cellulose polymorphys were studied by wide angle X-ray scattering and CP/MAS 13C NMR to elucidate, in particular, the factor, chain conformation or chain packing, affecting the CP/MAS 13C NMR spectra of the polymorphs. The CP/MAS 13C NMR spectra of the cellulose polymorphs were affected by chain conformation of the starting cellulose materials. The facility in transformation was attributed to chain packing, because the transformations from Cell I to Cell III and from Cell II to Cell IV, of which chain packings are very different from each other, were not facile.View full abstractDownload PDF (1016K) -
Shintarou KANBAYASHI, Takaaki ARAI1994 Volume 51 Issue 2 Pages 115-120
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThermodynamic parameters for polyelectrolyte complex (PEC) formation of carboxymethylcellulose (CMC-H) with different charge densities were determined. Poly (diallyldimethylammonium chloride) (PDDACl) and methyl glycol chitosan (MGCh) were used as polycations. Large negative standard free energy was gained by the formation of PEC in each system. The PEC formation of CMC-H of a low charge density showed a marked tendency to be exothemic and could be classified as an enthalpy dominating reaction On the other hand, the reaction of CMC-H with a large charge density showed a smaller exothermic tendency, and hence large positive entropy was gained, indicating the reaction to be an entropy dominating type. The molecular chain structures and the charge densities of PDDACl and MGCh had no effects on the temperature dependence of the PEC formation.View full abstractDownload PDF (1056K) -
Yoshio KASASHIMA, Yoshinori HARADA, Fumihiko AKUTSU, Kiyoshi NARUCHI, ...1994 Volume 51 Issue 2 Pages 121-126
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSMethyl methacrylate (MMA) -tri-n-butylborane (TBB) resins containing a suitable monomer which can promote adhesion to dentin have been developed. The effectiveness of 4-vinylbenzoic acid (4-VBA) and 3-vinylbenzoic acid (3-VBA) in MMA on the bonding to bovine dentin was studied. The highest tensile bond strengths were 14.2MPa in 1.0 wt% 4-VBA and 10.2MPa in 1.0wt% 3-VBA. The bond strengths to dentin were signficantly improved by 4-VBA or 3-VBA, but the hybrid layer formed by the diffusion of monomers into the demineralized dentin and by polymerization in situ did not contain so many copolymers. The bond strengths of 3-VBA were significantly lowered and the copolymer contents in the hybrid layer were lower than those of 4-VBA. These results were attributed to the polymerization before the diffusion of enough monomers into dentin. The rate of copolymerization with MMA is higher in 3-VBA than that in 4-VBA.View full abstractDownload PDF (2470K) -
Yoshio KASASHIMA, Yoshiyuki KATAYAMA, Fumihiko AKUTSU, Kiyoshi NARUCHI ...1994 Volume 51 Issue 2 Pages 127-132
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effectiveness of 4-vinylphthalic acid (4-VPA) and 4-vinylphthalic anhydride (4-VPAN) dissolved in methyl methacrylate (MMA) on the bonding to bovine dentin pretreated with 10-3 was studied in order to improve the adhesion of MMA-tri-n-butylborane (TBB) resin. 4-VPA concentrations in MMA were 0.0-2.5wt%. The highest tensile bond strength was 14.9MPa in 1.5wt% 4-VPA. However, the tensile bond strength was improved to 13.9 MPa in 5.0wt% 4-VPAN. There was no significant difference in tensile bond strength in 0.0-2.5wt% 4-VPAN. The hydrolysis rate of 4-VPAN was too slow to promote monomers into the pretreated dentin, which was identified with IR. The hydrolyzed 4-VPAN, 4-VPA, was a key element and 4-VPA in 4-VPAN as an impurity or the 4-VPAN hydrolyzed on the dentin was the effective element. The monomer which promotes adhesion to dentin needs to have both hydrophobic and hydrophibic groups.View full abstractDownload PDF (2596K) -
Hideo HAYASHI, Masa-aki KAKIMOTO, Yoshio IMAI1994 Volume 51 Issue 2 Pages 133-136
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSThe effect of molecular weight of poly [N, N′- (oxydi-p-phenylene) isophthalamide] (aramid) on the crystallization of the aramid in the poly (ether sulfone) (PES) /aramid polymerization-blended films and solution-blended films was investigated. The crystallinity of the armid in the polymerization-blended films after annealing decreased remarkably with increasing molecular weight of the aramid, while it tended to decrease more slowly in the solution. blended films.View full abstractDownload PDF (1053K) -
Hiroshi TSUBAKIHARA, Masakatsu YANOSHI, Kazuyuki OKADA, Akihiko SAKAMO ...1994 Volume 51 Issue 2 Pages 137-139
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSFree-standing films with smooth surfaces were obtained by evaporation of the solvent for dissolving chemically synthesized polyaniline powder. The films were clamped in a permeability cell, Permeability measurements were performed at 90, 110, 130, and 150°C with various inorganic gases. Activation energy and ability of gas separation are also discussed. After the heating, the polymer chains should be crosslinking with each other. which leads to the enhancement of the ability of gas separation, and the decrease in thegas permeability and the activatien energy.View full abstractDownload PDF (626K) -
Humihiko YAZAKI, Kiyotaka SUZUKI, YUBIN Zheng, Ryutoku YOSOMIYA1994 Volume 51 Issue 2 Pages 141-143
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSMechanical properties of Poly (ether ether ketone) (PEEK) /liquid crystalline copolyesters (LCP) blends have been investigated. They were improved and the ESCA adsorption caused by the calbonyl group was reduced by the addition of PEEK oligomers to the blends. The improvement of mechanical properties may be due to the formation of crosslinking by the oligomers, resulting in the improved compatibility between PEEK and LCP during the blending process.View full abstractDownload PDF (802K) -
Hiroshi TSUBAKIHARA, Hajime HIGUCHI, Kazuyuki OKADA, Akihiko SAKAMOTO1994 Volume 51 Issue 2 Pages 145-148
Published: February 25, 1994
Released on J-STAGE: March 15, 2010
JOURNAL FREE ACCESSFree-standing films were obtained by solution casting of polyaniline. Conductivities of the films were measured as functions of the protonation state (doped in pH 0.5-6 H2SO4 solution) and heating temperature. The conductivity increased with decreasing pH and heating temperature and is correlated with the background absorbance at high wavenumbers in the IR spectrum. The conductivity could estimated from the observed background peak in the IR spectrum.View full abstractDownload PDF (582K)
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