Kobunshi Kagaku
Online ISSN : 1884-8079
Print ISSN : 0023-2556
ISSN-L : 0023-2556
Volume 20, Issue 219
Displaying 1-15 of 15 articles from this issue
  • Masataka Okuyama, Tomomi Yanagida
    1963 Volume 20 Issue 219 Pages 385-390
    Published: July 25, 1963
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Dynamic viscoelasticity of polyvinylchloride (PVC) resins is measured at -150°C-+50°Cby the vibrating reed method (100-200 c/s). Viscoelasticity of these specimens is also measured at 15°C by the free torsional vibration method (0.05-1.7c/s). The samples are homopolymers plasticized by either dioctyl adipate (DOA) or tricresyl phosphate (TCP), copolymers of VC and vinyl acetate (VAc), and polyblend of PVC and PVAc.
    It is concluded that;(1) the β transition of PVC is not due to the movement of the end group of the molecules
    (2) the flexibility of PVC resins at low temperatures is due to the shape of the a absorption and the temperature at which this absorption appears and it does not depend on the, βabsorption.
    (3) plasticizing mechanism of the plasticizer is different from that due to the copolymerization.Addition of the plasticizer shifts the foot of a peak to lower temperature, while the copolymerization results in the appearance of a new, characteristic peak at 30°C. The new peak seems to be due to the micro-Brownian movement of the segments of VAc only, which are more flexible than VC chains. 4′ Department of Polymer Science, Osaka University (Nakanoshima, Kita-ku, Osaka)
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  • I. Permeation of Water Vapor through the Layer of Skim-milk Powder
    Teruo Makino, Shin-ichi Taneya
    1963 Volume 20 Issue 219 Pages 391-394
    Published: July 25, 1963
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    We observed various cases of one-dimensional diffusion phenomenon of water vapor passed through the layer of skim-milk powder. The assembly employed consists of three cylindrical dishes, one of which includes salt solution which maintains a dish at a constant humidity and the other contains absorbent and powder respectively. When a steady state is reached in the layer of powder, moisture content of powder becomes a equilibrium value. From these results, we can calculate the diffusion constant by two ways.
    The values of D obtained from sorption rate in powder and apparent Dd* from time lag of permeation is 4.37×10-6 (cm2/sec) and 3.50×10-4 (cm2/sec), respectively.
    Thus, the fact that Da* is larger than D may be due to the capillary flow of water vapor;i.e., at the initial stage of sorption, water vapor passes through pores between the powders as capillary flow and at the final stage, after moisture contents of the powder reached a steady state, diffusion also occurs as capillary flow.
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  • Masao Inoue, Hisao Yamada, Tokushige Fukami, Mikio Takagi
    1963 Volume 20 Issue 219 Pages 395-402
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    The effects of injection molding conditions spiral flow and molding shrinkage were measured for polystyrene using a spiral test mold in a Meiki injection molding machine with screw type preplasticizer. i) The relation among the spiral flow length X (cm), the melt temperature Tr (°C), the injection pressure P (kg/cm2), the mold temperature Tn, (°C) and the injection rate V (cm8/sec) is represented as follows: X=-21.4+0.00077 (Tr-125)(P+240) +0.058 Tm +0.14 V. ii) The molding shrinkage of spiral moldings along the direction of flow is smaller in the part close to the gate and larger close to the other end of the spiral, and the increasing rate of shrinkage in the former part is larger than in the latter. iii) The smaller shrinkage is obtained with higher melt temperature and higher mold temperature all over the spiral, and the effect of mold temperature is larger than that of melt temperature. The smaller shrinkage under higher injection pressure is obtained close to the gate and the effect is little close to the other end. The effect of injection rate is little.
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  • Yoshio Ishii, Yuya Yamashita, Shigeru Sumi
    1963 Volume 20 Issue 219 Pages 403-407
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    Al (OBut) 3 is an active catalyst for the polymerization of ethylene oxide and the catalytic activity is further increased by partial hydrolysis. The rate of polymerization and the degree of polymerization were investigated with Al (OPri), and Al (C) (Bu′), by varying the degree of hydrolysis and the catalyst concentration. We assume the coordinate polymerization with monomer adsorption as the rate determining step. Ti (OPr′), itself was ineffective, but was activated by partial hydrolysis. The partialy hydrolyzed Ti (OPri) 4 was further activated by Al Et3.
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  • Hiroshi Kawakami, Noboru Mori, Masao Sumi
    1963 Volume 20 Issue 219 Pages 408-412
    Published: July 25, 1963
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Bulk polymerization of vinyl acetate initiated with tri-n-butyl boron was studied kinetically at 10°C.
    The rate of polymerization was found to be expressed by an equation R p=const.[I]. The chain transfer constant of tri -n- butyl boron was 0.9. The apparent activation energy for the polymerization was calculated to be 6.0-6.5 kcal/mol.
    A number of polymerizations were carried out in the temperature range from -30°C to + 30°C. The average degrees of polymerization of polyvinyl acetate increased at first with increaing polymerization temperature and then decreased, passing through a maximum at about 30°C.
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  • I. Single Crystal of a-Amylose
    Nishio Hirai, Takeshi Yasui, Saburo Fujita, Yuhiko Yamashita
    1963 Volume 20 Issue 219 Pages 413-416
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    Corn starch was extracted with distilled water at 70°C. Butanol was added to the solution and amylose crystal was prepared in a-form. The crystals were studied by electron micrographs and low- and wide-angle X-ray analysis.
    It was confirmed that the crystals are about 100A thick, the spirals of amylose molecule in the lamellae were folded and their directions are normal to the wide surface of the lamellae.
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  • II. Relation between Molecular Weight Distribution and Mechanism of Polymerization
    Yutaka Sakurada, Minoru Ueda
    1963 Volume 20 Issue 219 Pages 417-422
    Published: July 25, 1963
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    Studies on the polymerization of a-methylstyrene by Al t3-Ti C14 catalytic system at various polymerization conditions, especially relation between aging conditions of catalyst and limiting viscosity number [r] of polymers obtained by the polymerization at -78°C, lead us to suppose that the two active species, i. e.(a) the intermediate complex (Ti C13) + (Al Et3 C1)- and (b) Al Et2 C1, are responsible for the polymerization in this system and the ratio of the two species vary with the progress of aging of the catalyst.
    To ascertain this conjecture, the poly-a-methylstyrene samples polymerized using the catalyst aged at four different aging conditions were fractionated by column elution method and the molecular weight distributions (MWD) thus obtained were compared.
    Results indicate that the MWD of polymer prepared with catalyst aged at -78°C has quite different charactristics from that of polymers obtained by the polymerization of a-methylstyrene in the presence of catalyst aged at 0°C. The MWD of the former has a peak around the MW of 5×104 and ranged only to ca. 6 x 105, whereas MW of the latter range up to ca. 2×106 irrespective of aging time. This latter is essentially the same distribution range as the sample polymerized in the presence of A1Et2 C1 only. The only difference observed within the latter samples is the shape of MWD curve, i. e. fractions of lower MW range decrease and on the contrary higher MW parts increase with the progress of aging of catalyst, indicating the increase of (b) species on the course of aging.
    These two facts obtained clearly indicate the consistence of our previous supposition on active species in the course of polymerization of a-methylstyrene at -78°C in the presenceof Ziegler catalyst.
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  • III. Polymerization of a-Methylstyrene with Various Alkylaluminums and Ti Cl, Catalyst Systems
    Yutaka Sakurada, Kiyokazu Imai, Masakazu Matsumoto
    1963 Volume 20 Issue 219 Pages 422-429
    Published: July 25, 1963
    Released on J-STAGE: February 20, 2012
    JOURNAL FREE ACCESS
    The polymerization of a-methylstyrene initiated by Al Et, Cl3-n, (n=1, 2)-Ti CI4 systems or Al R3-Ti Cl4 systems of different size R (alkyl group) at -78°C was studied. For Al Etn Cl3, Al Et C12 and Al Et2C1, and for Ai R3, Al Et3, Al (i-Bu) 3 and Al (Hex) 3 were used respectively. The conversion and the degree of polymerization (DP) at a definit time are influenced distinctly by the kinds of alkylaluminums and by the aging conditions of the catalyst systems. The order of catalyst activity defined by the DP of the polymers are as follows:
    _??_
    The corresponding DP varied within the range from 500 to 3000 for the first series and from 800 to 5000 for the second series respectively. It is speculated that the cause of the above mentioned phenomena due to the different counter anions of active species. The structure of the active species are discussed on the basis of the reaction process of A1R3 or A1Eta Cl3-n with Ti Cl4.
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  • IV. Properties of Poly-α-Methylstyrene Prepared with Various Catalysts
    Yutaka Sakurada, Kiyokazu Imai, Masakazu Matsumoto
    1963 Volume 20 Issue 219 Pages 429-435
    Published: July 25, 1963
    Released on J-STAGE: February 20, 2012
    JOURNAL FREE ACCESS
    Properties of poly-α-methylstyrene by AlEt3-TiCl4 at -78°C were compared from the standpoint of the stereoregularity with those of poly-a-methylstyrene by BF3·EOEt2 and TiCl4at -78°C, and by metallic Na and K at room temperature. Since crystallization of these polymers is very difficult, glass transition temperature, infrared absorption spectrum, density and solubility were measured in amorphous state. Some differences depending on the polymerization conditions were observed in glass transition temperature and infrared spectrum. The glass transition temperature of the polymer prepared with AlEt3-TiCl4 catalyst is 117°C, and that of the polymer prepared with metallic K catalyst is 107°C.(The degree of polymerization of both polymers is ca. 3000) The intensity of absorption peak at 885 cm-1 in the infrared absorption spectrum is affected by the polymerization conditions. These differences may result from differences in the stereoregularity of the polymer. The density is 1.0610±0.0005 independent of polymerization conditions. However, when the polymer is heated above the glass transition temperature, it changes to 1.0630±0.0005. The solubility in methyl ethyl ketone depends on the polymerization conditions, but the relationship between the solubility and the stereoregularity of the polymer is not clear. The following shows the order of catalyst activity defined by the stereoregularity estimated from the results of glass transition temperature and infrared spectrum.
    _??_
    “The stereoregularity ” used here may mean “the isotacticity.”
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  • V. X-Ray Diagram of Poly-a-Methylstyrene
    Yutaka Sakurada, Takani Mochizuki, Masakazu Matsumoto
    1963 Volume 20 Issue 219 Pages 436-442
    Published: July 25, 1963
    Released on J-STAGE: December 22, 2010
    JOURNAL FREE ACCESS
    X-ray scattering intensity curves of poly-a-methylstyrene prepared with various catalysts were obtained. They consist of two amorphous halos having maxima at the scattering angle of ca. 10°, and 16°, respectively. The spacings corresponding to these halos are 9.1 Å and 5.4 Å. The intensity ratio of the inner halo to the outer one increase and the scattering angle of the inner halo decrease with increasing stereoregularity of the polymer respectively. The order of the catalyst activity defined by the stereoregularity is as follows:
    AlEt3-TiCl4=BF3·OEt2>TiCl4>Na>K
    The intensity ratio of the two halos increases with rising temperature when the polymer is heated above the glass transition temperature and also increases when treated with solvent such as methyl ethyl ketone or n-heptane.
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  • I. Properties of Methylolbenzoguanamine
    Hiroshige Ohno
    1963 Volume 20 Issue 219 Pages 443-449
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    The reaction of benzoguanamine with formaldehyde was studied in detail, and the results were summerized as follows.
    1) The condensation products of benzoguanamine with formaldehyde (mono-, di-, tri-, and tetra-methvlolbenzoguanamines) were obtained in crystalline state from weak alkaline solution.
    2) The functionality of benzoguanamine against formaldehyde is 3.5, and activation energy is 1.3 kcal/mol and heat of reaction is 3.8 kcal/mol.
    3) The methylolbenzoguanamine is easily alkylated in alcoholic solution by acidic catalyst. The alkylated products are identified by the paperchromatography using the Tollens' reagent and hydrogen iodide as detecting reagents.
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  • III. Optical Study on Deformation Mechanism of Nylon 6 Spherulites
    Tadayoshi Aihara, Osamu Yoshizaki, Eiichi Nagai
    1963 Volume 20 Issue 219 Pages 450-455
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    It has been ascertained by X-ray measurement that the positive spherulite which is obserbed in undrawn gut of Nylon 6 spun from the melt through a wide nozzle has a crystalline modification (γ-form) different from the structure (α or β-form) well established by Bunn.
    When subjected to drawing, its form changes from a sphere to an ellipsoid and, in the extreme, to a cylinder.
    It is revealed that the birefringence measured at the circular section of an elongated spherulite has a larger positive value with respect to the direction of radius than that found for the unelongated one.
    The morphological change accompanies the transformation of crystalline form from γ to α(or β), resulting in parallel alignment of the molecular chains along direction of cylindrical axis of the elongated spherulite.
    Based on the general concept about polymer spherulites in which molecular chains are oriented tangentially, the above phenomenon was analysed with the measured values of refractive indices along three directions of the oriented films having the two different kinds of crystalline structures (γ and α(or β) form). From the determination of the molecular chain (unit cell) arrangement in the spherulites before and after deformation, it has been concluded that the deformation mechanism of the spherulites by stretching is essentially consistent with that assumed before by us for the film made from the formic acid solution and also for the single crystal obtained from the glycerine solution, both having the same crystalline structure as that in the spherulites.
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  • Ichiro Sakurada, Yasuyoshi Sakaguchi, Jun Nishino, Takehisa Iwagaki
    1963 Volume 20 Issue 219 Pages 456-460
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    Acrylic acid was polymerized in bulk or solvents of low polarity such as benzene at relatively high temperature with radical initiators. Potentiometric titrations of aqueous solutions of the polymers were carried out using NaOH, (n-Butyl) 4NOH and Ba (OH) 2. These polymers showed somewhat higher pK-values than those of polyacrylic acid samples obtained by polymerization in water or derived from usual polymethyl acrylate, indicating that they have a more isotactic structure. On the other hand, the potentiometric titration behaviors of polymethacrylic acid samples obtained by radical polymerization were practically independent of the nature of solvents used for the polymerization. Some discussions were given for the results.
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  • Taro Suminoe, Noboru Yamazaki, Shu Kambara
    1963 Volume 20 Issue 219 Pages 461-466
    Published: July 25, 1963
    Released on J-STAGE: October 14, 2010
    JOURNAL FREE ACCESS
    Copolymerization of propylene-butadiene by AlEt3-TiCl4 catalyst and copolymerization of ethylene-propylene by AlEt3-VCI4 catalyst were carried out. In both cases copolymers obtained by the catalysts prepared in the presence of only propylene gave more propylene content than that obtained by the catalyst prepared in the presence of both monomers. In ethylenepropylene copolymerization both kinds of catalysts, prepared in the presence of only ethylene and monomer mixtures gave copolymers having the same composition. From the IR spectra measurement and the fractional precipitation of ethylene-propylene copolymer, it was found that the copolymer molecules contained comparatively long sequences of methylene unit.
    From these results, it was concluded that the copolymerization activity of the catalysts varried with the kind of the olefin present during the catalyst forming, and the difference of the activity was assumed to be due to the substantial change of the catalyst or variation of the surface structure of the catalyst species which affects to the absorption of monomers on the catalysts. In ethylene-propylene copolymerization a tendency to produce a block copolymer was found.
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  • Taro Suminoe
    1963 Volume 20 Issue 219 Pages 467-472
    Published: July 25, 1963
    Released on J-STAGE: February 18, 2011
    JOURNAL FREE ACCESS
    In the copolymerization reaction the reactivity of the Ziegler type catalyst prepared in the presence of two monomers was controlled by the more reactive monomer. In the case of ethylene-isoprene copolymerization it was found that the presence of a small amount of more reactive ethylene in large amount of less reactive isoprene scarcely affected the catalytic activity. The two kinds of copolymers were obtained, one of which was exclusively consisted of isoprene and the other of both isoprene and ethylene. By infrared spectrum analysis, it was found that the copolymer obtained was to be a block copolymer, and contained more 3, 4 additions of isoprene than that in the homopolymer obtained in the same polymerization condition.
    From these results, the followings are concluded. The kind of monomer which added to the end of the glowing polymer chain is controlled by the monomer unit of the growing end. Two or more kinds of active site are presented in this catalyst system.
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