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Volume 14, Issue 146
Displaying 1-8 of 8 articles from this issue
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III. The Effect of Solvents on Reduced Viscosity of Dilute Dimethylpolysiloxane SolutionMasatami Takeda, Akira Yamada, Taeko Saito1957 Volume 14 Issue 146 Pages 265-269
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSThe dilute reduced viscosity of dimethylpolysiloxane has been measured in eight kinds ofsolvents. A general relation between [η] and k′ is applicable to the results. In the goodsolvent intrinsic viscosity [η] is larger and Hugginsk′ is smaller. Moreover the relationbetween (k′+β)(β is that given by Fuoss and Mead in their viscosity formula) and k′ ork′[η] 2 and [η] is agreed with the usual prediction fairly well. The order from the good to thepoor solvents ranked in cyclohexan, tetrahydrofuran, carbontetrachloride, n-heptan, benzene, toluene, chlorobenzene and methylethylketone. This result was also checked from the [η]-M relation, the latter quantity being obtained from osmotic pressure measurment.View full abstractDownload PDF (772K) -
V. Vapor Pressure of Acetone in Nitrocellulose SolutionHaruo Takenaka1957 Volume 14 Issue 146 Pages 270-276
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSVapor pressures of acetone solutions of three kinds of nitrocellulose were measured overall range of concentration and at every 5°C between 20-60°C. Newly designed glass systemswere employed for measurements. Remarkable hysterisis was observed with regard to thetemperature change in higher concentrations than75%View full abstractDownload PDF (2762K) -
Ryozo Inoue, Akira Ichikawa, Kaoru Furukawa1957 Volume 14 Issue 146 Pages 277-283
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSIn the synthesis of butadiene from ethylalcohol and acetaldehyde, one of the main reactionsis the polycondensation of acetaldehyde to crotonaldehyde, hexadienal etc. In this paper thepolycondensation of acetaldehyde in the presence of Ta2O5-SiO2 catalyst at elevated temperatures was studied. Velocity constants for the condensation of acetaldehyde to acetaldehyde, acetaldehyde to crotonaldehyde and crotonaldehyde to crotonaldehyde, and adsorption coefficients of acetaldehyde and crotonaldehyde were observed kinetically. The velocity constant decreasesand adsorption coefficient increases with the increase of the molecular weight of aldehyde inthe condensation product of acetaldehyde.The distribution of the reaction product was discussedon the basis of random polycondensation.View full abstractDownload PDF (1176K) -
I. The Quantitative Determination of Carboxyl Groups and its Content in Relation to the Conditions of the PreparationIchiro Sakurada, Osamu Yoshizaki1957 Volume 14 Issue 146 Pages 284-290
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSIt is shown that the carboxyl groups of polyvinyl alcohol may be quantitatively determinedby conductometric titration. The dissociation constant of the carboxyl group is found to be1.6×10-5 by electrometric titration. By heating polyvinyl alcohol with carboxyl groups in anaqueous solution of dilute hydrochloric acid the formation of lactone rings is observed. Fromthe mechanism of the polymerization of vinylacetate the carboxyl seems to be attached to apolyvinyl alcohol molecule as an end group. Polyvinyl alcohol fractions prepared from polyvinylacetate obtained by the bulk polymerization contain on the average one carboxyl groupper one polymer molecule, whereas those from polyvinyl acetate obtained by the solutionpolymerization in solvents with larger transfer constants such as acetone and ethanol contain 0.2 carboxyl group per one polymer molecule.View full abstractDownload PDF (1208K) -
III. Studies of Viscosity in DMF-Water SystemTakashi Shibukawa, Kohei Nakaguchi1957 Volume 14 Issue 146 Pages 291-294
Published: June 25, 1957
Released on J-STAGE: December 22, 2010
JOURNAL FREE ACCESSAs the results on the studies of the viscosities of PAN-DMF-water system, it was foundthe followings. 1) The intrinsic viscosity [η] decreases with the increasing amounts of waterin these systems. 2) Precipitation points under the dissolving condition of 40°C, 12 hrs., areon the ratio of 93.4: 6.6 (vol.ratio) of DMF: water, and at this point [η] at 30°C and 60°C have the same value. 3) A binary mixtures of DMF-H20 are good solvent when the contentof water are below 6.6% and are the poor solvent above 6.6%. 4) Above 6.6% Huggins' constant at 60°C is greater and below 6.6, ; smaller than that at 30°C.View full abstractDownload PDF (740K) -
IV. Studies of Viscosity in DMF-Ether-Heptane SystemTakashi Shibukawa, Kohei Nakaguchi1957 Volume 14 Issue 146 Pages 294-297
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSThe intrinsic viscosity [η] of PAN-DMF solution decreases with the addition of precipitant (ether-heptane), and Huggins' constant k′ increases with the addition. The precipitatingpowers vary with changes of the ratios of ether-heptane. When the amount of heptane areover a half, PAN-DMF-ether-heptane system becomes heterogeneous. Therefore these systemscannot be used for the fractionation. The series of the precipitation power was found to beas follows,
H20>Ethanol>Methanol>Butanol>Ether-Heptane>BenzolView full abstractDownload PDF (738K) -
VII. Redox Polymerization Catalized by the K2S2O8-AgNO3 SystemIsamu Yamazaki1957 Volume 14 Issue 146 Pages 298-305
Published: June 25, 1957
Released on J-STAGE: December 22, 2010
JOURNAL FREE ACCESSThe consumption rate of acrylonitrile initiated by K2S2O6-AgNO redox recipe, was investigatedin various conditions and the recipes was satisfactorily expressed by the following equation.
-dm/dt=kp(kd/kt)1/2 (ac/(1+kt1c/kmi+kt2a/kim))1/2m
in which kp, kd, kt kt1, and kt2: are velocity constants of the respective elementary reaction, and m: monomer concentration, c: initiator concentration, a: reductant concentration.View full abstractDownload PDF (1352K) -
VIII. Effect of KCNSAkira Takahashi, Isamu Yamazaki1957 Volume 14 Issue 146 Pages 305-310
Published: June 25, 1957
Released on J-STAGE: October 14, 2010
JOURNAL FREE ACCESSIt was found that inorganic rhodanates are very effective to the depression of the degreeof polymerization, and its action was determined in various monomer and initiator-concentrations. The over-all activation energy of the polymerization was measured to be 15 kcal/molin the presence of KCNS.View full abstractDownload PDF (853K)
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