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Volume 29, Issue 5
Displaying 1-10 of 10 articles from this issue
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Magnetic PropertyKOHJI TOHYAMA1973 Volume 29 Issue 5 Pages P167-P172
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
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YOSHINOBU NAYATANI1973 Volume 29 Issue 5 Pages P173-P179
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
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MASAKI KATO1973 Volume 29 Issue 5 Pages P180-P184
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
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Hiroshi Kawakami, Akira Miyoski1973 Volume 29 Issue 5 Pages T191-T196
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe change in fine structures, by hot-drawing and heat treatment (slack), of polyvinyl alcohol (PVA) fibers spun with aqueous solution of Na2SO4 (Fiber G) and NaOH (Fiber C) as coagulant was investigated by means of X-ray diffraction, differential thermal analysis and optical dichroism.
The fiber-forming process, i.e., the change of the solvent coaguelant composition along the spinning line, in NaOH solution is quite different from that in Na2SO4 solution. Fiber C has a higher drawability and less shrinkage compared with Fiber G.
By hot-drawing, longer crystalline and shorter amorphous regions are formed in Fiber C, than in Fiber G. The lattice distortions of the second-kind are also low in Fiber C. These difference of fine structure was remarkably reflected in the melting point and dimensional stability. It was assumed that the mobility of the molecular chains during hot-drawing and heat treatment depends on the comformation in as-spun fibers.View full abstractDownload PDF (366K) -
Hiroshi Kawakami, Akira Miyoshi, Kokichi Kimura1973 Volume 29 Issue 5 Pages T197-T204
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe relation between the fine structures and mechanical properties was investigated on polyvinyl alcohol fibers spun in coagulating baths of Na2SO4 (G) or NaOH (C), followed by hotdrawing and relaxation heat treatment.
Three mechanical loss peaks are observed around 20°C, 70°C and 120°C, which are known as βa, αa and βc absorptions, respectively. The intensities of these absorptions decrease with draw ratio, and increase with shrinkage ratio. The αa absorption is attributed to the microbrownian motion of amorphous chains and disappears when the amorphous orientation function Fa is extrapolated to 1. The fine structures of fiber G and fiber C are reflected on the relation between the peak intensity of αa absorption and Fa. The βc absorption is considered to be attributed to the low ordered amorphous region. Dynamic modulus E' increases and the lowering of E' by heating becomes smaller with the increase in the total orientation function Ft. Highly drawn fibers have higher Young's modulus, while highly relaxed fibers have lower modulus. Young's modulus is reasonably explained using a series model of crystalline and amorphous regions. The breaking strength and elongation are remarkably affected by the state of amorphous regions. The breaking strength and elongation strongly depend on Fa. Very high hot-drawing was possible for fiber C than fiber G. This is because for the high molecular orientation and the high modulus, high strength and low elongation.
The behaviours for the knot strength were different between fiber G and fiber C, reflecting the difference of the structures of amorphous region. It should be considered that the knot strength is related to other factors such as the length of amorphous region, in addition to Fa.View full abstractDownload PDF (443K) -
Jiro Shimizu, Kozo Shimazaki1973 Volume 29 Issue 5 Pages T205-T210
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe birefringence was measured along a liquid filament in the polypropylene (Chisso Co., Ltd. Grade No.1016) melt spinning process. According to the results, after the first gradual ascent of birefringence, it still increases abruptly and stops its development along the spin line. (Fig. 1) The first gradual and second abrupt ascents are attributable to the deformation of filament (attenuation) and the crystallization respectively.
It was found that the birefringence of the liquid filament can be related to the spinning stress as follows: where Δn0 is the birefringence in deformation domain and σ the stress (dyn/cm2) of filament.
The birefringence in the second abrupt increase region Δn is expressed as follows: where Δn′0 is the birefringence of the starting point of crystallization and is estimated by equation (1) from the spinning tension and the cross-section of take-up filament, and t (in sec) is the time for cooling down the filament from 110°C to 75°C. The second abrupt development of birefringence occurs mainly during this period (t).
When the spinning is performed without cooling air, equation (2) can be written in terms of the take-up speed and diameter of the filament instead of t.
In this way, the birefringence of a filament, immediately after take-up, is prescribed by the stress and the cooling speed of the filament.View full abstractDownload PDF (479K) -
Shinji Ogasawara, Shigetaka Kuroiwa1973 Volume 29 Issue 5 Pages T211-T215
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIt has previously been reported that the acid dyes such as Orange II (C. I. Acid Orange 7) and Diacid Supra Red 3B (C. I. Acid Red 35) formed 1:1 complexes with gallic acid residue of tannic acid (Chinese gallotannin) in the aqueous solutions by either hydrogen bonding or van der Waals bonding. In the present paper, the bonding type between these acid dyes and tannic acid is investigated spectrophotometrically.
The equilibrium constants for the complex formation were obtained by Scott's Method from the changes of absorbance of the dye solutions resulted from the complex formation. The changes of thermodynamic characteristic functions, i.e., ΔG°, ΔH° and ΔS° were calculated from these equilibrium constants in the usual manner. Comparison of ΔG° between the two dyes shows that Orange II has weaker affinity for tannic acid than that of Diacid Supra Red 3B. The values of ΔH° and ΔS, were -7.02Kcal/mol and -4.50cal/mol•deg for Orange II, and -10.1Kcal/mol and -13.8cal/mol•deg for Diacid Supra Red 3B, respectively. These ΔH° values (negative) are comparable to one (for Orange II) or two (for Diacid Supra Red 3B) moles of hydrogen bonding between nitrogen atom and hydroxyl group in general compounds (-4--7Kcal/mol), and the ΔH° value (negative) for Diacid Supra Red 3B is larger than that for Orange II. This suggests that the former dye forms energetically more stable complex with tannic acid than the latter one. The fact that the ΔS° values for both dyes are negative means that the complex formation is accompanied by an increase of restraining molecular species from the freedom in the solutions.
Since the pKa values of the dyes, which were estimated by means of spectrophotometric method, are both about 11, it is considered that a single intramolecular hydrogen bonding may be formed between one of the nitrogen atoms in azo group and the hydroxyl group in the respective dye molecule. However, the remaining nitrogen atom in the azo group has an ability to form the intermolecular hydrogen bonding with the hydroxyl group of other molecule. Since Diacid Supra Red 3B, in addition to this, has another nitrogen atom in the acetoamide group in a molecule, it is able to form the 1:1 complex with gallic acid residue of tannic acid by two hydrogen bonding, whereas Orange II forms the 1:1 complex by one hydrogen bonding. This reflects in the difference in ΔH° value between two dyes.
In any event, it may be concluded reasonably that the complexes of the acid dyes with tannic acid are formed principally by the hydrogen bonding between nitrogen atom in each dye and hydroxyl group of gallic acid residue of tannic acid.View full abstractDownload PDF (329K) -
Mamoru Nango, Akira Katayama, Nobuhiko Kuroki1973 Volume 29 Issue 5 Pages T216-T219
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe position of the -OH proton resonance of methanesulfonic acid has been measured at various dilution in several solvents containing -OH group, such as water, methanol and ethyleneglycol. In all solvents studied, a single resonance line was observed. The proton resonance of the -OH group moves first to low field and to high field with increasing dilution. From the dilution curves it was found that in water, methanol and ethyleneglycol this movement of the -OH signal to high field commences at the following concentrations (more ratio of the sulfonic acid to the solvents); 3:1, 2:1 and 4:1. This suggests that sulfonic acid forms 3:1, 2:1 and 4:1 complexes with water, methanol and ethyleneglycol where hydrogen bonds play major roles.
The chemical shifts for the ionizable proton in aqueous, methanol and ethyleneglycol solutions of methanesulfonic acid and benzenesulfonic acid have been measured at 34°C. In all cases studied, a single resonance line was observed and the proton chemical schifts dependedd upon the concentration of the acids. From the observed proton chemical shifts relative to the pure solvents, the degrees of ionization of the sulfonic acids have been calculated. The ionization constants estimated in the solvents were in the following order; water ≥ ethyleneglycol > methanol.View full abstractDownload PDF (242K) -
Masaaki Sugiura1973 Volume 29 Issue 5 Pages T220-T223
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe ζ-potential at the interfaces between degummed silk fibre and the aqueous solutions containing a number of trivalent metal nitrates was measured by means of the streaming potential method. The trivalent metals used were Al, Ga, In, Cr, Fe, Rh, Sc, Y, La, Sm, Tb, Er and Yb.
At pH 5.0, generally, the negative ζ-potential decreases with increasing concentration of metal salt. In the cases of Al, Ga, In, Cr, Fe, Rh and Sc, it reverses its sign at concentrations in the region of 10-6-10-4M and then approaches a limiting positive value which differs for each metal salt: the sequence for the reversal of charge concentrations is Fe<Ga<In<Rh<Sc<Al<Cr. In other cases, the ζ-potential does not reverse its sign at least up to the concentration of 2_??_10-4M: the curves of the ζ-potential for these metal salts nearly coincide with one another.
At pH 3.7, in the cases of Ga, Fe and Rh, a significant increase in the positive ζ-potential is observed at concentrations above 10-6M: the order of increasing ζ-potential is Fe>Ga>Rh. In the cases of Al, In, Cr and Sc, with increasing concentration of metal salt, the ζ-potential decreases and nearly becomes zero at concentrations in the region of 10-6-10-5M. At higher concentrations it rises slightly. In other cases, the ζ-potential decreases with increasing concentration of metal salt and reaches a negative value. The decrease in the ζ-potential is due to the adsorption of nitrate ions: this was discussed by measuring the ζ-potential for potassium nitrate.View full abstractDownload PDF (306K) -
Koji Furuta, Eiichi Kuze1973 Volume 29 Issue 5 Pages T224-T228
Published: May 10, 1973
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSA visual pattern recognizing method was applied to the evaluation of the fabric structures.
This paper describes a system using pattern-recognition techniques and picture processing techniques.
The pattern of fabrics is read by a two-dimensional optical-electric sensor connected to a digital computer and is represented by a two-dimensional array of points showing the transparency distribution of fabrics.
The computer extracts the feature information from pattern of fabrics using the concept of “Cell”. The cells are divided into five gray levels according to the threshold logic to separate the abnormal region from the normal and to classify the abnormal.View full abstractDownload PDF (1036K)
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