KOBUNSHI RONBUNSHU
Online ISSN : 1881-5685
Print ISSN : 0386-2186
ISSN-L : 0386-2186
Volume 35, Issue 12
Displaying 1-11 of 11 articles from this issue
  • Toshihiro KASHIMA, Kuniomi ETO
    1978 Volume 35 Issue 12 Pages 751-758
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    The behavior of melting temperature (MT) for annealed copolyester (I) was studied by differential scanning calorimeter (DSC). MT of I of terephthalic acid series was observed to increase by heattreatment below the MT of I. The MT of the annealed I was found to deviate from the Flory equation for the MT of random I. (1) In the case when I is composed of acid or glycol both having long aliphatic chain, the degree of increase in MT is remarkable, while for I having benzene ring the tendency is small. (2) With decreasing crystallinity of I the MT increases. X-ray diffraction measurements show that this increase is independent of the spacing.
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  • Hiroshi UENO, Shinya OTSUKA, Kazuo TAIRA, Akira KISHIMOTO
    1978 Volume 35 Issue 12 Pages 759-764
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Short-time (30ms) adhesion of Nylon 12 was examined from the view point of the diffusion properties of polymer molecules. Diffusion coefficients DA of Nylon 12 in melt, which were measured by the microspectrophotometry using a dye-tagging technique, showed much larger values than the bulk diffusion coefficients DB which were estimated from melt viscosity and seemed to correspond to the self-diffusion coefficients of molten Nylon 12 molecules. Apparent activation energy for diffusion EDA was much smaller than that for viscous flow Eη or EDB. Molecular weight dependence of DA was weaker than that of DB. The diffusion behavior suggests that the short-time adhesion of these polymer films is accounted for the segmental diffusion of Nylon 12 chains. This was also supported by the similar behavior observed in the local diffusion coefficients DL which were estimated from the fluorescence depolarization measurement for molten Nylon 12. The behavior of lap shear strength of Nylon 12 laminated on steel plate conducted for the short-time and the moderate time (120s) adhesion was consistent with the molecular mechanism.
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  • Yohji IMAI, Eiichi MASUHARA, Koichi TAKAKURA, Osamu NAKAJI, Shuzo YAMA ...
    1978 Volume 35 Issue 12 Pages 765-770
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Poly (vinyl alcohol) -acrylonitrile graft copolymer membranes show good mechanical strength and solute permeability, but are poor in water permeability. The present work was undertaken to improve water permeability of the membranes without the decrease in the strength. The graft copolymer membranes were soaked in a mixed solvent of dimethyl sulfoxide and dimethylformamide at 60°C for 3 minutes and then immersed in water. Water content, mechanical properties, permeability of uric acid, vitamine B12 and water of the treated membranes were measured. Permeability was greatly improved by treatment with the solvent of suitable composition. The improvement is considered to be primarily owing to the increase in microporosity of the domains of polyacrylonitrile. The graft copolymer membranes had segregated microphase structure and the polyacrylonitrile phase was dispersed in the poly (vinyl alcohol) matrix.
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  • Kaoru FURUKAWA, Katsuo TAKE, Chiaki TSUKAMOTO, Toshio OZEKI, Osamu YOS ...
    1978 Volume 35 Issue 12 Pages 771-778
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    After-polycondensation of polycaprolactam was investigated using a pilot plant consisted of a pressurized continuous reactor, an atmospheric equilibrium reactor, and a vacuum evaporator. The properties of the polymer obtained from the first reactor coincided with those estimated from equilibrium polymerization experiments in a closed system. After-polycondensation process in falling thin film and the evaporation of caprolactam in the evaporator were analyzed by treating the falling liquid as a hydrodynamic system. It was found in this analysis that the rate of polycondensation in the falling film system can be well explained using the rate constants deduced from static polymerization experiments. Meanwhile, at the bottom of the evaporator, the rate of polycondensation was lowered because of the difficulty in removing the water from the system. By adopting a modified equation for the bottom part, the polycondensation process in the evaporator could be completely explained. It was also deduced that there was a critical limiting depth of the reaction system to make the water evaporation from the polymer impossible. Analysis of the whole experimental data indicates that the reaction rate depends upon other factors such as contents of chain stabilizers and H3PO4, temperature, pressure of steam, and retention time.
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  • Tomoyuki KASEMURA, Katsumi SUZUKI, Fumio UZI, Takashi KONDO, Toshio HA ...
    1978 Volume 35 Issue 12 Pages 779-786
    Published: December 25, 1978
    Released on J-STAGE: March 25, 2010
    JOURNAL FREE ACCESS
    Poly (vinyl alcohol) -acrylonitrile graft copolymer membranes show good mechanical strength and solute permeability, but are poor in water permeability. The present work was undertaken to improve water permeability of the membranes without the decrease in the strength. The graft copolymer membranes were soaked in a mixed solvent of dimethyl sulfoxide and dimethylformamide at 60°C for 3 minutes and then immersed in water. Water content, mechanical properties, permeability of uric acid, vitamine B12 and water of the treated membranes were measured. Permeability was greatly improved by treatment with the solvent of suitable composition. The improvement is considered to be primarily owing to the increase in microporosity of the domains of polyacrylonitrile. The graft copolymer membranes had segregated microphase structure and the polyacrylonitrile phase was dispersed in the poly (vinyl alcohol) matrix.
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  • Hiroyoshi KAMATANI, Shigeji KONAGAYA
    1978 Volume 35 Issue 12 Pages 787-794
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Polycondensation of bis (2-hydroxyethyl) terephthalate (BHET) was studied in the presence of mixed complexes [M (II) (acac) 2 (BHET); M=Mn, Co, Zn] which were prepared by the reaction of BHET with bivalent metal acetylacetonates [M (II) (acac) 2 (H2O) 2] inacetone. The structure of the mixed complexes was speculated from the measurements of infrared spectra, reflectance curves, thermal analysis and elemental analysis. Polycondensation was initiated when the acetylacetone was released from the mixed complex by the ligand exchange reaction. The rate of polycondensation was found to be proportional to the square of the hydroxyl group concentration. The both rate of polycondensation and of the side reaction which leads to the formation of an ester diethylene glycol increased as the kind of metals in the catalyst changed in the following order: Mn (II) <Co (II) <Zn (II). It was concluded on the bases of the kinetics of the reaction and the structure of the complexes that increased nucleophilicity of the hydroxyl groups due to the coordinaton of BHET to the metal plays an important role in accelerating the reactions.
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  • Bunichiro YAMADA, Minoru YOSHIOKA, Takayuki OTSU
    1978 Volume 35 Issue 12 Pages 795-801
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    The absolute values of propagation rate constant (kp) and termination rate constant (kt) of N, N-dimethylacrylamide were determined by means of a rotating sector method in bulk at 30°C. The overall rate of polymerization initiated with α, α′-azobisisobutyronitrile was found to be proportional to square root of the initiator concentration and to the monomer concentration, indicating that the polymerization proceeded by a chain mechanism involving the termination by the coupling or disproportionation of growing radical. The absolute values of kp and kt determined at 30°C were 27200 and 3.54×109 l mol-1, s-1, respectively. Reactivities of N, N-dimethylacrylamide and poly (N, N-dimethylacrylamide) radical were discussed on the basis of the rate constants of cross-propagation reactions in the copolymerization with other monomers. Although N, N-dimethylacrylamide was as reactive as common conjugated monomers, the polymer radical was found to be much more reactive than common conjugated polymer radicals such as polystyrene or poly (methyl acrylate) radical. The unexpected high reactivity of the polymer radical seems to be accounted for by the decrease in the interaction of the unpaired electron of the radical with the carbonyl π electrons due to the independent interaction of the lone pair electrons on the nitrogen with π electrons of the carbonyl group.
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  • Toshio MATSUKURA, Takatoshi KINOSHITA, Akira TAKIZAWA, Yoshiharu TSUJI ...
    1978 Volume 35 Issue 12 Pages 803-805
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Water sorption capacity of Poly (tetrahydropyran-2, 6-diyliminocarbonyl) [I] is about 3 times as high as those of nylon 6 and nylon 66 and almost the same order of that of wool. The sorption isotherm of I is independent of temperature. This suggests a large number of relatively weak polar sites are present in I. Water vapor permeability coefficient P of I is one order higher than that of cellophane membrane at high relative vapor pressure, and the relative vapor pressur dependence of P is smaller than the case of cellophane membrane. The activation energy of water vapor diffusion coefficient is relatively small, and is 7.6 and 4.1 kcal/mol at the relative vapor pressure 0.2 and 0.8, respectively. These values are close to that of water permeability, 6.9 kcal/mol. Above results suggest that the interaction between polar sites in I is relatively weak and the polymer has a relaxed structure.
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  • Yoshio IMAI, Mitsuru UEDA, Masahiro II
    1978 Volume 35 Issue 12 Pages 807-809
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Aromatic polysulfonates of high molecular weights have been prepared from aromatic disulfonyl chlorides and sodium salts of bisphenols by the interfacial polycondensation in methylene chloride-water system using quaternary ammonium salts as a phase-transfer catalyst. Aromatic polysufonates obtained were soluble in a wide range of solvents including methylene chloride and tetrahydrofuran. Thermogravimetry showed that these polymers began to decompose around 300°C both in air and nitrogen atmospheres.
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  • Kiyokazu IMAI, Unpei MAEDA, Masakazu MATSUMOTO
    1978 Volume 35 Issue 12 Pages 811-813
    Published: December 25, 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
    Poly (vinyl alcohol) derived from the solution polymerization of vinyl acetate in dimethyl sulfoxide has been characterized by swelling degree in water, clouding rate in aqueous dimethyl sulfoxide solution, and aging tendency of concentrated aqueous solution. The results showed that the polymer was apparently different in the properties as compared with conventional poly (vinyl alcohol) obtained from the polymerization in bulk or in methyl alcohol, indicating that dimethyl sulfoxide solvent gives polymers with low regularity or crystallinity.
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  • 1978 Volume 35 Issue 12 Pages 828
    Published: 1978
    Released on J-STAGE: February 26, 2010
    JOURNAL FREE ACCESS
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