Kobunshi Kagaku
Online ISSN : 1884-8079
Print ISSN : 0023-2556
ISSN-L : 0023-2556
Volume 24, Issue 270
Displaying 1-12 of 12 articles from this issue
  • Shizunobu Hashimoto, Yasuhiko Nagasuna
    1967 Volume 24 Issue 270 Pages 625-632
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The synthesis and these physical properties, such as the apperaance, the melting point, the solution viscosity, and the melt spinnable property of co-polyesters containing pyridine ring in the main chain, have been studied in detail. Co-polyester of 2, 6-dimethy 1-3, 5-dicarbethoxy pyridine, dimethyl terephthalate, and ethylene glycol were prepared by the melt polymerization. On the other hand, those of pyridine dicarboxylic acid dichloride (isocinchomeronyl chloride or dinicotinyl chloride), aliphatic dicarboxylic acid dichloride (succinyl chloride or adipyl chloride), and bisphenol A were prepared by the interfacial polymerization.
    Independently of the molar ratio of the component of the reactants, all of the co-polyesters produced by the melt polymerization were yellow solids, while all of the co-polyesters given by the interfacial polymerization were colorless solids. The co-polyesters having higher melting point, even if they have been produced by the latter method, turned brown in the melting processes.
    The eutectic curves for these co-polyesters were prepared with the change of the molar ratio of the acid components in each of all co-polymerizations. Furthermore, the heats and the entropies of the fusion per the repeating unit were established on the basis of the Flory's fusion theory for the random co-polymer.
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  • Shizunobu Hashimoto, Yasuhiko Nagasuna
    1967 Volume 24 Issue 270 Pages 633-639
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The thermal stabilities of the polyimides, which were prepared from 2, 3, 5, 6-pyridine tetracarboxylic acid and aromatic diamines in polyphosphoric acid have been stadied.
    Polyphosporic acid was used as a condensation agent as well as a solvent for this reaction. The raection was carried out below 180°C, because the reactants decomposed and no polyimides were obtained above 220°C.
    The presence of phoshorous in the polyimides prepared gave lower thermal stabilities. As these polimides have pyridine rings in the main chain, their thermal stabilities were lower than that of corresponding polypiromerit imides.
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  • Yasuyoshi Sakaguchi, Jun Nishino, Masaru Tanaka, Katuyuki Tamaki
    1967 Volume 24 Issue 270 Pages 640-644
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    o-Vinyl benzoic acid (o-VBA) was synthesized and polymerized by using radical initiators, Poly-o-VBA (B) polymerized in a dilute aqueous sohltion of pH 7 showed different infrared absorption spectrum, solubility and potentiometric titration curve from those of poly-o-VBA (A) polymerized in benzene. From the results, it seems that the both polymers may have different stereoregulalities from each other. Furthermore, aqueous solution of P-o-VBA (B) showed a lower pH-value and a higher conductivity than those of poly-p-vinyl benzoic acid polymerized under the similar condition. This may be mainly attributed to a larger intrinsic ionizability of carboxyl groups of the o-polymer.
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  • Yasuyoshi Sakaguchi, Jun Nishino, Syota Nakamura, Katsuyuki Tamaki
    1967 Volume 24 Issue 270 Pages 645-648
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    N, N-dimethyl acrylamide (I), N, N-diisopropyl acrylamide (II), N-tert-butyl acrylamide (III), tetra-n-butyl ammonium acrylate (IV) and diethyl methylenemalonate (V) were polymerized in bulk or in benzene using a radical initiator. The polymers from (I), (II), (III) and (V) were hydrolysed to polyacrylic acid (PAA), and the polymer of (IV) was converted to PAA through cation exchange. Aqueous solutions of these PAA's were potentiometrically titrated with sodium hydroxide. The pH-values were in oder of usual PAA PAA from (I) >PAA from (III) >PAA from (II) PAA from (IV) PAA from (V) >PAA from triphenylmethyl acrylate. Conductometric titration curves of the PAA's were also compared to each other, and such differences of titration curves between PAA samples were discussed in connection with their stereo-regularities.
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  • Hitoshi Yamaoka, Katsuo Nishiyama, Koichiro Hayashi, Seizo Okamura
    1967 Volume 24 Issue 270 Pages 649-654
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The gamma-ray induced polymerization of p-chlorostyrene (Cl-St) and p-bromostyrene (Br-St), and the copolymerizations of these monomers with styrene (St) were studied in methylene chloride solution.
    In the polymerization of Cl-St at 9°C, the kinetic order of the rate of polymerization (Rp) was 0.47 in reference to the dose rate. φγel (=φsm), which expresses the relative ratio of free radical production in the solvent and in the monomer, was determined as 5.4 from the effect of the monomer concentration on Rp. On the other hand, in the polymerization at -78°C, Rp was linearly proportional to the dose rate and the polymerization was strongly retarded by the addition of diethylamine (DEA).
    In the copolymerization of Cl-St with St, the monomer reactivity ratios (MRR) at 9°C were almost same as those obtained by conventional radical initiators and MRR at -78°C coincided with those obtained by cationic catalysts. When copolymerized at -40°C, the intermediate values of MRR between those at 9°C and -78°C were obtained. MRR determined in the presences of DEA and DPPH were in good agreement with those at 9°C and -78°C without additives, respectively.
    The similar results were also obtained in the polymerization of Br-St and the copolymerization of Br-St with St.
    From these results, it was concluded that the polymerizations at 9°C and -78°C proceeded by radical and cationic mechanism, respectively, and the both mechanisms were simultaneouly operative at -40°C.
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  • Toshinobu Higashimura, Yoshizo Kitagawa, Seizo Okamura
    1967 Volume 24 Issue 270 Pages 655-661
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    t-Butyl propenyl ether (tBPE) (cis-isomer) was polymerized by BF3·O (C2H5) 2 to compare with the polymerizability of t-butyl vinyl ether (tBVE). Although a homopolymer could be produced from tBPE, both its rate of polymerization and molecular weight were low. Also in the copolymerization of tBPE with tBVE, tBVE was less reactive than tBVE. In vinyl ethers having such a bulky alkoxy group as t-butoxy group, the introduction of methyl group into β-position decreased the reactivity of vinyl ethers due to the steric hindrance. This behavior is just reverse of n-alkyl propenyl ethers.
    Crystalline poly-tBPE could be obtained in the polymerization in toluene at low temperature, but in methylene chloride only amorphous polymer was obtained. These polymers were converted to poly- (β-methyl vinyl acetate) by acetylating agent (acetic anhydride and ZnCl2). However, pure poly- (β-methyl vinyl alcohol) could not be obtained by saponification of poly- (β-methyl vinyl acetate).
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  • Kenji Kamide, Masahiko Sanada
    1967 Volume 24 Issue 270 Pages 662-678
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    Thermal analysis by differential scanning calorimeter (DSC) was carried out on unorientated film of isotactic polypropylene in order to study the change in fine structure during heat-treatment. Fractions and whole polymers ranging in molecular weight from 4×103 to 4.7×105 are moulded into unorientated film by using the hot press method. It was acertained from NMR measurement on o-dichlorobenzene solution at 150°C that microtacticity was independent of molecular weight. Procedure of heat-treatment in detail was taken into consideration. From DSC thermogram, three characteristic temperatures are defined; Tm1, temperature of onset of melting, Tm2, temperature at which melting velocity reaches maximum, Tm3, temperature at which the trace of crystallites melts. Tm3 from DSC diagram is in very good agreement with the peak temperature of DTA (differential thermal analysis) curve. By comparing Tm3 with melting temperature obtained from dilatometry on welldeveloped crystals, Tm3 is proved to be the apparent melting temperature. Melting point is very s1 ightly influenced by annealing temperature except the narrow temperature range of heat-treatment, usually 150-170°C for polymer having molecular weight higher than 4×104, for which 160-165°C treatment gives maximum melting temperature. Temperature range of melting for fractions is narrower than that for whole polymers when temperature above 150°C is used as annealing temperature. Both Tm2 and Tm3 change little by heat-treatment below 150°C, but slightly increases to the saturated value at temperature above 155°C.
    Small peak or shoulder appears in DSC diagram corresponding to the heat-treatment in the range 70-150°C not only for annealed film but also for annealed solution grown crystals. Theappearance of the small peak is independent of annealing method, heating media, duration of heat-treatment, molecular weight and it's distribution. The peak temperature is several degrees higher than the annealing temperature. It is experimentally shown that the appearance of small peak can not be ascribed to melting of portion of lower degree of micretacticity, partial melting of β-form, transition of smectic form to monoclinic one, degradation, disorientation of crystallites before melting, and that small peak may be due to the melting of thermally unstable crystallites having monoclinic form of highly isotactic chains, which are formed during heat-treatment.
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  • Kenji Kamide, Hidehiko Kobayashi, Yukio Miyazaki, Chozo Nakayama
    1967 Volume 24 Issue 270 Pages 679-698
    Published: October 25, 1967
    Released on J-STAGE: July 27, 2010
    JOURNAL FREE ACCESS
    The light scattering and viscosity measurements were carried out on fractions in N, N′ -dimethylformamide at 20°C. The fractions chosen for this study were polymers prepared by suspension (S) or precipitation (P) polymerization in aqueous or organic (benzene (B) or n-heptane (H)) system with redox (R) or non-redox (nR) catalyst as initiator. Fractions were, in advance, characterized by high resolution nuclear magnetic resonance and infra-red spectra, leading to the conclusion that the degree of microtacticity of polymeric chains is almost constant independent of molecular weight and polymerization conditions. The larger values of refractive increment than those in literatures were obtained for (P-nR) polymer. For fractions polymerized in benzene, the fluorescence had a large effect on the Zimm plot giving the slope with minus sign for c=0 line in the range of small angle of scattering, even if 546mμ as incident light was used. The optical anisotropy of the chain effected little on this kind of distortion appearing in the Zimm plot. Apparent depolarization, of which the magnitude remarkably depended on the conditions of polymerization, decreased with increase of molecular weight. After corrections of fluoresoence, 0.01-0.02 as depolarization factor of scattered light was obtained irrespective of the molecular weight and the preparative procedure.
    Relationships between the intrinsic viscosity and molecular weight were determined for polymers except (P-nR (B)): [η] (dl/g) =4.66×10-4Mw0.71 and for (P-nR (B)) polymer: [η] (dl/g) =4.29×10-4Mw0.71. On the other hand, the identical relationships were obtained between the radius of gyration (SS2) z1/2 or second virial coefficient A2 and molecular weight irrespective of the polymerization conditions: (SS2) z1/2 (cm) =1.27×10-9Mw0.62 and A2 (ml/gg2) =4.94×10-2Mw-0.27. The correlationships among the parameters in the above equations were discussed in detail.
    Applicability of the Stockmayer-Fixman plot was examined. Flory constant K=3.1×10-3 for (P-nR (B)) polymer and 3.6×10-3 for other polymers were determined by egtrapolating the linear portion of the plot to Mw1/2. From viscosity measurements on the redox polymer in ethylene carbonate-water (85: 15, in weight) system at 44°C for which A2 vanishes, K=3.5×10-3 was estimated. The experimental results that the polymerization conditions influenced only the parameter Km in the Mark-Houwink-Sakurada equation [η] =Km Mwa, but not on a and molecular weight dependence fo (SS2) z1/2 or A2 were resonably interpreted by the recent solution theories.
    Fluorescence appearing in dimethylformamide solution did not depend on the content in amide, carboxylic acid and it's ester existing in polymer as abnormal structures. Fluorescence of the redox polymer was of ionic and that of (P-nR (B)) polymer was of non-ionic type.
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  • I. The case when the scissions of both random chains and crosslinkages occur
    Kenkici Murakami, Saburo Tamura, Yoshitaka Takano, Hiroyuki Kurumiya
    1967 Volume 24 Issue 270 Pages 699-705
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    To make clear the degradation mechanism of cross-linked polymers is a very urgent work in connection with the evaluation of polymer stability and chemical antioxidants.
    There have long been two extremely different opinions about the mechanism of scission of network chain polymers, especially about natural rubber vulcanizates. One is that only random chain scission of this vulcanizates occurs in the oxidation reaction from the experiments and theory by A.V. Tobolsky. Another is that only cross-link scission of them occurs in the oxidation reaction from the experiments and theory by Berry and Watson.
    The recent results of cross-linked polymers inculding this vulcanizates show that both scissions may occur at the same time in many cases.
    So the authors make an attempt to derive the general equation for both scissions for the purpose of the possibility for judging which scission occur preferably and of finding out the quantitative amounts of scission chains using the experimental results. We generalize the case that one cross-linkage is cut in the minimum model perfect chain network
    As the results, the next equation was derived for vulcanizates both scission occur
    (1)
    The equation (1) in the both cases of k→0 and k→∞, conforms to those proposed bTobolsky. Assuming the more practically probable mechanism in the scission of cross- linked polymer, the following equation (2) obtained by modification of equation (1) is derived.
    (2)
    The theoretical relation between Q (t) /M0 and Nt/N0 is shown and discussed.
    Then three kinds A, B and C of natural rubbers cured by sulphur were prepared, and D of that cured by peroxide was prepared. A, B and C have the different initial den- sities of cross-linking.
    The actual density, N0 for the four samples was obtained by using the equation of f (0) =N0RT (α-α-2) and by the swelling method using the equation of Flory-Rhener.
    According to the results obtained already, both scissions of main chains and cross-link sites occur at the same time for A, B and C, but the only mainchain scission occur or the sample D.
    So equation (3) is obtained for the sample D, because k=0 in the equation of
    (3)
    or
    (4)
    As the equation of is applicable for the samples of A, B and C, and qm (t) is equal for the four samples under the same condition, the equation (5) is established by subsutituting the equation (4) into the above equation.
    (5)
    Using the experimental data of (ft/f0) A, (ft/f0) D and the known value of N0, A, N0, D, and M0, KA is calculated from the equation (5).
    Similarly KB, KC are obtained.
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  • Improved theoretical equations for infinite network structure
    Kenkichi Murakami, Saburo Tamura
    1967 Volume 24 Issue 270 Pages 706-710
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    In the former paper, the theory in which the perfect network chain structure was assumed as the pyramid type was dealt.
    In this paper, the structure is assumed as the infinite network, and the assumptions that 2x-mer chains which appeared after the scissions of cross-link sites do not behave as the effective chains for stress, but behave as those after the scissions of neighbouring xmer chains was presented as the more real one and the improved theory taking these into account was derived.
    Furthermore, the theory in which both scissions of main chains and that of cross-link sites nearby occurs at the same time was derived.
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  • II. Effects of Some Conditions on Critical Shear Rate of Aqueous PVA Solutions
    Yukichi Go, Suzi Matsuzawa, Yoshiyuki Kondo, Kazuo Nakamura
    1967 Volume 24 Issue 270 Pages 711-714
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The effects of the solution temperature, the velocity of increase in the shear rate and the shearing stress on the coagulation of aqueous solutions of syndiotacticity-rich PVA were studied.
    PVAs derived from poly (vinyl formate) prepared at low temperatures and from poly (vinyl trifluoroacetate) were used.
    The results indicated that the lower the solution temperature or the slower the increase in the shear rate, the smaller the critical shear rate γc, and that the lower the solution temperature, the smaller the shear stress at coagulation point.
    Considering the results in the previous report together, it was concluded that the tacticity of PVA, the smaller the γc.
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  • III. The Study on the Dissolved State of Some Stereoregular Poly (Vinyl Alcohols) in Water with Viscometry
    Yukichi Go, Shuzi Matsuzawa, Kazuo Nakamura, Isoo Saito, Takao Hayashi ...
    1967 Volume 24 Issue 270 Pages 715-720
    Published: October 25, 1967
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The dissolved state of some syndiotactic-rich poly (vinyl alcohols) in water was studied with viscometry in order to clarify in detail the behavior of mechanical denaturation of aqueous PVA solutions.
    In the case of atactic PVA Einstein's hydrodynamic equivalent spheres existed in the closest Packing at the critical concentration of apparent activation energy of flow (Eη). The syndiotactic-rich PVA which was derived from poly (vinyl formate) prepared at 0°C and had nearly the same syndiotactic (diad) % with the atactic PVA showed a similar result with that of the atactic PVA solution in Eη-concentration (C) relationship. Therefore, mechanical denaturation occurs to PVA slightly differing in stereoregurality. On the other hand, PVA which was derived from poly (vinyl formate) prepared at -40°C and had a higher syndiotactic (diad) % than the atactic PVA showed a different result from that of the atactic PVA solution.
    PVA containing 5 mol % isopropenyl alcohol showed the different results from that of the atactic PVA solution in Eη-C relationship. Seemingly that the contact of methyl side chain with hydroxyl one takes the place of the contact between hydroxyl side chains.
    The extent of polymer concentration effective to the mechanical denaturation ranged from the critical concentration to the concentration at which all the contacts changed into the entanglements.
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