All issues
Predecessor
Volume 28, Issue 2
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
XIII : THERMODYNAMICAL CONSIDERATION ON THE DEHYDROGENATION OF n-PARAFFINS BY QUINONES.SHU KAMBARA, NOBORU YAMAZAKI1955 Volume 28 Issue 2 Pages 66-69,126
Published: February 15, 1955
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSIn order to investigate, as a fundamental study of the vulcanization reaction, the behaviour of hydrogen, the structure unit of rubber hydrocarbon, the authors pursue this behaviour with dehydrogenation reaction, n-paraffins were used as the model of hydrocarbon and quinones as dehydrogenating agent. At first the reaction was considered thermodynamical functions the authors concluded that the reaction progresses as follows;-n-paraffin are dehydrogenated at reaction temperature of 100-150°C by quinones, and on calculating the change in free energy during the reaction of producing n-paraffins and hydroquinones, obtained the value of about-10 Kcal/mol.View full abstractDownload PDF (607K) -
XIV : LOW-TEMPERATURE DEHYDROGENATION REACTION OF n-PARAFFINS BY QUINONESSHU KAMBARA, NOBORU YAMAZAKI1955 Volume 28 Issue 2 Pages 70-72
Published: February 15, 1955
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSIn the previous paper (XIII), the authors found that according to the thermodynamical consideration, n-paraffins are dehydrogenated by quinones at 100150°C, and carried on experiments on this point. The authors found that n-paraffins are, in general, stable to quinones, but dehydrogenation occurs at the end with an increase in number of carbon atoms, though it is of a small quantity. The authors detected at the same time hydroquinones.View full abstractDownload PDF (510K) -
(II) COMBINED SULFUR OF MBT ACCELERATED VULCANIZED RUBBEREIICHI MORITA1955 Volume 28 Issue 2 Pages 73-78,125
Published: February 15, 1955
Released on J-STAGE: February 05, 2010
JOURNAL FREE ACCESSThe amount of various types of sulfur in gum mix accelerated with MBT were determined and the changes of these values with extension of cure were observed.
Preliminary study of the method which was originally used by Kambara and Ohkita (R. C. T. 25 209 (1952)) for the determination of thioketone-type combined sulfur in pure rubber-sulfur mix, using a H2O2-glacial acetic acid mixture (H2O2-HAc), was made as to its applicability to MBT accelerated compound. Experiments on the reactions of sulfer in compounds likely to be found in the vulcanizates, such as ZnS, MBT, MBTS, Zn salt of MBT, toward H2O2-HAC oxidation showed that the ZnS-type sulfur was completely converted and slightly more than one-half equivalent of the total sulfur in a mole of MBT-Zn salt was converted into sulfates, while MBT and MBTS were much less reactive. Considering these reactions and recent reports on the amount of MBT and its transformation products formed during vulcanization, the amount of sulfur within the value obtained by the H2O2-HAc oxidation after acetone extraction (SH2O2) due to the MBT originally added was negligible and consequently, the sulfur combined to rubber and removable by the H2O2-HAC treatment as sulfates, expressed as S2, may be given approximately as the difference of SH2O2 and ZnS-sulfur.
This Sα first increased and then decreased after passing through a maximum, which was about one-third of the total sulfur used in the mix, with extension of curing time. On the other hand, organically combined sulfur which was not removable by the oxidation treatment (Sβ) increased steadily with extention of cure, thereby, revealing that transformation of Sα, to Sβ occurred.
These changes of Sα and Sβ coincide with the case of pure rubber-sulfur vulcanizates observed by the forementioned workers.
As the mutual relation of changes in the amount of the different types of sulfur were identical for vulcanizates cured at 20, 40, and 60 psi steam pressure, irrespective of curing temperature, it seems that vulcanization reaction within this curing range were analogous in relation to sulfur. However, the re were no constant relation between Sβ and network density, derived from data on swelling, modulus or elongation at constant stress.
These latter results showed that higher network density was obtained at the lower curing temperature, revealing that thermal scission not involving sulfur changes occured at higher temperatures.View full abstractDownload PDF (1023K) -
(PART 1) ON THE LEAKAGE STOPPING APPARATUS OF THE HIGH PRESSURE STEAMSABURO YAMAMOTO, AKIRA ISE1955 Volume 28 Issue 2 Pages 79-86,125
Published: February 15, 1955
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSThe present oven curing procedures of the rubber insulaed wires have many working steps.
In order to simplify this process the writers have studied on the continuous vulcanizing machine, and reached to the practical use in their works.
In this paper the writers report on the leakage stopping apparatus of the high pressure steam for the continuous vulcanization and the abstract is as follows.
(1) The leakage stopping apparatus of the high pressure steam :
From the theoretical discussion of the labyrinth packing, they decided clearly that one labyrinth packing decreases the pressure of steam.
At the entrance part of labyrinth packing.
ΔPI=ρ2g (u1-u2)2
At the outlet part
ΔPII=ρ2g (u3-u4)2
Where ΔPI : ΔPII : decrease of pressure at the entrance part and at the outlet part.
ρ : density of steaitl.
g : acceleration of gravity.
u1, u2 : Velocity of the steam at the front anc back of the entrance part of labyrinth packing.
u3, u4 : velocity of the steam at the front and back of the outlet part of labyrinth packing.
(2) As the results of their practical tests, the mechanism using the labyrinth, rubber and water packing is the most suitable for the apparatus of the continious vulcanization.View full abstractDownload PDF (1130K) -
[in Japanese]1955 Volume 28 Issue 2 Pages 87-94
Published: February 15, 1955
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (1698K) -
[in Japanese]1955 Volume 28 Issue 2 Pages 95-102
Published: February 15, 1955
Released on J-STAGE: October 16, 2009
JOURNAL FREE ACCESSDownload PDF (1490K) -
[in Japanese]1955 Volume 28 Issue 2 Pages 103-111
Published: February 15, 1955
Released on J-STAGE: February 05, 2010
JOURNAL FREE ACCESS
- |<
- <
- 1
- >
- >|