巻号一覧
25 巻, 8 号
選択された号の論文の6件中1～6を表示しています
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石崎 舜三, 蔵本 直哉, 大沼 紀幸1969 年 25 巻 8 号 p. 347-353
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーFatigue phenomena of tire cords should be considered as the behavior of composite material which consists of rubber, adhesive and textiles.
In this report, the fatigue mechanism of textiles is discussed. Polyethylene terephthalate bristle is used as a model sample of tire cords in order to reduce troublesome factoys in a fatigue test as much as possible.
The sample is fatigued under compressive and tensile deformation.
The results obtained may be summarized as follows;
(1) There is a great difference in behavior of fatigue between the tensile deformation and compressive deformation
In compression fatigue, the cracks at about 45°C to the fiber axis are observed in the sample and crack growth causes strength loss that leads to ultimate failure.
In tension fatigue, the oblique cracks do not appear in the sample and the strength of the sample scarcely decreases. But the data which show the decrease of density and the increase of absorption of para-ehlorophenol by fatigued sample imply that internal microscopic defects are produced in the sample.
(2) When the sample is deformed by cyclic tensile and compressive stresses which are of the same strain, the sample is fatigued mainly by compressive stress.
(3) The compression fatigue involves the processes of: Occurrence of cracks→growth of cracks→rupture by tensile stress.
(4) In the tire cords the fatigue mechanism works in the order as stated in (3) above抄録全体を表示PDF形式でダウンロード (1633K) -
岩倉 賢次, 藤村 敏一1969 年 25 巻 8 号 p. 354-359
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーIn this paper, the water-penetrating pressure in the composite fabrics of hydrophilic and hydrophobic yarns is discussed in relation to the wettability of the materials and the structure of fabrics.
The following results were obtained;
(1) The penetrating pressure P is given by the following equation as a function of the advancing contact angles of both component materials, θ1 θ2, radius of yarns, γ, the gap between the yarns, D, and the surface tension of liquid, γ,
P=γ(I/Rw+I/Rf)
Rw and Rf are calculated for the warps and the wefts, respectively.
(2) The observed pressure agrees approximately with the calculated value, except in the case where one of dvancing contact angles of the components is smaller than the critical angle. In such a case, the observed pressure is much lower than the calculated. However, the deviation becomes smaller when the hydrophilic yarns are neglected.
(3) Generally, the pressure reduces steeply with the decrease of the advancing contact angle of one component or with the increase of mixed ratio of the hydrophilic component.
(4) The water-penetrating pressure in composite fabrics of hydrophilic and hydrophobic yarns is dependent not only on the mixed ratio of yarns but also on the structure. Thus the proper design improves the comfortability of the apparel with little deterioration of water-repellency.抄録全体を表示PDF形式でダウンロード (361K) -
浅生 貞夫, 木下 陸肥路1969 年 25 巻 8 号 p. 360-367
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーA specific acoustic impedance of a fiber assembly was measured by the standing wave method, and an attenuation constant and a propagation velocity of a sound wave in the fiber assembly were computed by a following new method. Given the specific acoustic impedance Zl and Zl of fiber assemblies of l and 2l in thickness, Zl=W coth bl Z2l=W coth 2 bl where W is the characteristic impedance and b the propagation constant. As Zl and Z2l are measurable, b is calculated. The attenuation constant and the propagation velocity are obtained from the b as a function of frequency.
The relation between these values and factors relating to the structure of fiber assembly were investigated. The results are as follows:
(1) A sound absorption mechanism of a fiber assembly is explained by the frequency characteristic curve of specific acoustic impedance. The resistance part of the impedance varies largely with frequency under a certain structure of the assembly.
(2) The relation between the attenuation constant β and the porosity P (%) may be expressed by; β=A(100-P) where A is a constant decided by a fiber fineness, β increases nearly in proportion to the total surface area of fibers in a unit volume of the assembly.
(3) The sound propagation velocity in a fiber assembly of viscosity resistance type increases proportionally to log f (Hz) and decreases as the porosity of the assembly decreaese. A characteristic curve of sound propagation velocity in a fiber assembly of resonance type is considerably different from that of viscosity resistance type. In a low frequency range it is similar to the one of the viscosity resistance type, but at a critical frequncy in a middle or high frequency range the velocity increases discontinuously. The critical frequency becomes lower, as the porosity of the assembly is the smaller. Accordingly in a high frequency range the sound propagation velocity is larger in the fiber assembly of lower porosity than in that of higher porosity.抄録全体を表示PDF形式でダウンロード (558K) -
北条 舒正, 白井 汪芳, 大和 公子1969 年 25 巻 8 号 p. 368-372
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーThe formation of fibroin copper complexes in various pH ranges was investigated. Silk fibroin was dissolved in 9.3M lithium bromide at 40°C, and dialyzed thoroughly against water for four days.
The complexes of fibroin with cupric ion were formed at various pH ranges in aqueous solution. Titration curves and ultra violet absorption spectra of fibroin in solutions at various pH values with and without cupric ion were investigated.
An absorption maximum was observed at about 700 mμ in cupric fibroin solution at pH 7.5, where as the maximum was shifted to 540mμ in cupric fibroin solntions in higher pH than 8.5. The band which might be due to OH groups of the tyrosine residues was changed in the presense of cupric ion. The optical rotatory dispersion curves of silk fibroin and the copper complexes in aqueous solutions were measured. In solutions of the cupric complexes formed above pH 8.5, the cotton effect displays through at 540 mμ. The moffitt parameters, -a0, for the visible rotatory dispersion of cupric fibroin complex solution, fell sharply at pH 8.5 and b0 was crose to zero.
On the basis of the results mentioned above, it is presumed that the effect of cupric ion on silk fibroin solution is greatly reduced above pH 8.5.抄録全体を表示PDF形式でダウンロード (268K) -
高岸 徹, 片山 明, 黒木 宣彦1969 年 25 巻 8 号 p. 373-380
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーThe solubililities of disperse dyes such as azobenzene and p-hydroxyazobenzene in water and aqueous tetraalkylammonium halide (R4NX) solutions were determined at 5°C intervals from 5°C to 40°C. The tetraalkylammonium halides used in this work are tetramethylammonium bromide (Me4NBr), tetraethylammonium chloride (Et4NCl), tetraethylammonium bromide (Et4NBr), tetraethylammonium iodide (Et4NI), and tetra-n-butylammonium bromide (n-Bu4NBr). All experiments were carried ou_??_ below the critical micell concentration of R4NX.
From the results the thermodynamic parameters for the process (A) which consists of the transfer of one mole of the solute from a water environment to an aqueous R4NX solution have been calculated from the equations (1), (2) and (3).
Process (A): disperse dye in water (mole fraction N0)→ disperse dye in aqueous R4NX solution (mole fraction N)
In any case the solubilities of disperse dyes in aqueous R4NX solutions increase regularly with the R4NX concentration for any particular R4NX. It is to be noted that the effects of R4NX on the solubilities are in the follwing order, Me4NBr<Et4NCl<Et4NBr<Et4NI<n-Bu4NBr. This fact indicates that an increase in the solubitity by addition of R4NX is largely dependent on the alkyl chain length of the added R4NX and suggests that the hydrophobic portion of R4NX plays an important role in enhancement of the solubilities of disperse dyes in water. This salting-in maybe explained in terms of an interaction between the dye and the tetraalkylammonium ion, which is induced by the increase in the structure of water near large nonpolar parts of the dye and the organic ion.
The resulting ΔSu•trans• are positive for any particular R4NX and ΔHtrans• are positive except for-p-hydroxyazobenzene in aqueous Me4NBr and Et4NI solutions, so it is clear that the favorable transfer of the disperse dye from a water environment to an aqueous R4NX solution comes from the contribution of entropy term. This result strongly suggests that the increase in the solubilities of disperse dyes is the result of the binding of the nonpolar portions of the tetraalkylammoniumm ion to the disperse dye molecule and that this binding comes from the hydrophobic interaction between the hydrocarbon portions of the R4NX and the nonpolar portions of the disperse dye.抄録全体を表示PDF形式でダウンロード (546K) -
高岸 徹, 片山 明, 黒木 宣彦1969 年 25 巻 8 号 p. 381-386
発行日: 1969/08/10
公開日: 2008/11/28
ジャーナル フリーThe solubilities of disperse dyes such as azobenzene and p-hydroxyazobenzene in water and aqueous hydrotropic agent solutions were determined at 5°C intervals from 5°C to 40°C. The hydrotropic agents used in this work are urea, N-monomethylurea, N, N′-dimethylurea, formamide, and N, N-dimethylformamide.
From the results the thermodynamic parameters for the process (A) which consists of the transfer of one mole of the solute from a water environment to an aqueous hydrotropic agent solution have been calculated from the equations (1), (2), and (3). Process (A): disperse dye in water (mole fraction N0)→ disperse dye in aqueous hydrotropic agent solution (mole fraction N)
In any case the solubilities of disperse dyes in aqueous hydrotropic agent solutions increase regularly with the concentration of the hydrotropic agents. The effects of hydrotropic agents on the solubilities are in the following order, urea<formamide<monomethylurea<dimethylurea<dimethylformamide.
The resulting ΔSu•trans• are all positive and ΔHtrans• are zero or positive, so it is clear that the favorable transfer of the disperse dyes from a water environment to an aqueous hydrotropic agent solution comes from the contribution of entropy term.
From a consideration of the above data and the other physicochemical properties, it seems most reasonable to conclude that (1) urea and formamide disrupt directly the ordered water structure around the nonpolar parts of the disperse dye, and (2) in aqueous monomethylurea, dimethylurea and dimethylformamide solutions there exist hydrophobic interactions between nonpolar parts of the dye and alkyl chains of these hydrotropic agents.抄録全体を表示PDF形式でダウンロード (416K)
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