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Volume 37, Issue 5
Displaying 1-9 of 9 articles from this issue
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YOSHINARI KOBAYASHI1981 Volume 37 Issue 5 Pages P173-P181
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (724K) -
Minekazu Kodama, Yasuo Furuhashi1981 Volume 37 Issue 5 Pages T177-T180
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to elucidate the mechanism of mechanical dispersion in fiber-reinforced composite, temperature dependence of the dynamic viscoelastic properties in simple extention was studied for the epoxy resin composite reinforced with satin woven glass cloth, in which the symmetrical angle between the directions of extension and each fiber axis of warp and woof was adjusted to ±67.5° (COA67.5), ±45° (COA45), and ±22.5° (COA22.5).
The composite reinforced with the cloth in which the fiber axis of warp coincided with the direction of extension (COA0), and that reinforced with uniaxially aligned continuous glass fiber to the direction of extension (ROA0) were also used as samples.
Although the primary transition is merely observed for COA67.5 and COA45, a sub-transition appears at a temperature above the primary transition for COA22.5 and COA0. The sub-transition for COA0 appears more distinctly separated from the primary transition as compared with the case of COA22.5. E″ and tan δ vs. temperature curves for ROA0 are hardly distinguishable from those for COA0.
Our results are similar to those reported by Reed6), in which mechanical dispersion in flexural deformation is studied for the unidirectional epoxy-glass fiber composite at various fiber orientation angles.
This implies that the effect of fiber intersection has no serious influence on the mechanical dispersion behaviors. The present and Reed's results can be explained by the mechanism proposed by Lipatov et al.7) that the separation of the sub and primary transitions occurs if the boundary layers formed on the surface of reinforcement and the bulk polymer phase are aligned parallel to the direction of deformation. The sub-transition reported earlier by us for composites reinforced with randomly distributed short glass fiber is also clearly explained by the mechanism proposed by Lipatov et al.View full abstractDownload PDF (273K) -
Tomiji Wakida1981 Volume 37 Issue 5 Pages T181-T185
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn a previous paper, it became clear that the improved dyeing properties of polyester fiber treated with various compositions of organic solvent/water high pressure steam and organic solvent/water solution is closely related to the change of the fine structure of the fiber. As an increase of the structural disorder in the amorphous region of the fiber facilitates the thermal motion of the molecular chain, it is naturally considered that the treatment with organic solvent/water changes remarkably the dynamic viscoelastic properties such as loss tangent tan δ, dynamic modulus E′, and dynamic loss modulus E″ Peak temperature of tan δ and E″ of the film treated with hot water shifted a little to the higher temperature side compared to that of untreated film. On the other hand temperature dispersion of tan δ of the films treated with benzyl alcohol/water and butanol/water became broad and its peak temperature shifted to the lower temperature side. Furthermore E′ decreased and the peak temperature of E″ shifted greatly to the lower temperature side by the organic solvent/water treatment.
It is clear that the treatment of polyester fiber with organic solvent/water disorders the amorphous region of the fiber. As a result, microbrownian motion of the molecular chain becomes more active even at low temperature, which leads to an increase of dyeing properties. Increased dye uptake of polyester fiber by treating with organic solvent/water correlates with the decrease of peak temperature of E″.View full abstractDownload PDF (355K) -
TOSHIYOSHI TANUMA1981 Volume 37 Issue 5 Pages P182-P190
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe wool fibre is a natural two-phase polymer consisting of essentially crystalline water-impenetrable microfibrils of about 80 A diameter hexagonally packed in a non-crystalline or amorphous water-penetrable matrix. Because of this composite or two-phase structure, the torsional modulus of the fibre is much lower than its tensile modulus and is much sensitive to the absorption of moisture. At saturation, the wool fibre absorbs 33% moisture which acts as a plasticizer from the mechanical viewpoint.
The viscoelastic properties of the wool fibre are critically dependent on the relative humidity and temperature and also the degree of “aging” undergone by the fibre since it was last immersed in water. The stress relaxation behaviour of wool fibres under varying ambient conditions is very closely related to the rheological properties of wool and wool/synthetic blended fabrics. The inelastic component of fabric deformation can be divided into a fibre viscoelastic component and an inter-fibre frictional component, the latter component depending largely on the yarn and fabric structure, processing conditions and the nature and degree of finish applied to the fabric. The use of blends of natural and synthetic fibres has been used extensively in recent times to control the rheological properties of fabrics. (S. Kawabata)View full abstractDownload PDF (1356K) -
Yasusato Sugahara, Akira Takahashi, Shiro Takahashi1981 Volume 37 Issue 5 Pages T186-T191
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe photo-induced graft polymerization of MMA onto cellulose was carried out using NaIO4 as an initiator. The following results were obtained.
Graft polymerization of MMA onto cellulose in an aqueous system was accelerated with a small amount of NaIO4 and the optimum concentration was 3_??_5 mmol/l. The degree of grafting and the apparent numbers of grafted chains increased when cellulose was grafted at pH 5.4 and the time of treatment with NaIO4 was prolonged (C=O content <20 mmol/100g cellulose). The apparent activation energies for the over all and the grafting calculated from the initial polymerization rates were 10.7 and 11.3 kcal/mol, respectively. These results show that the graft polymerization proceeds mainly via the photolysis of the carbonyl groups produced by the reaction between cellulose and NaIO4, However, the carbonyl contents increase over 20 mmol/100g cellulose, then the termination between cellulose radicals made by the photolysis and growing polymer radicals occurs more easily than the addition of the monomer onto cellulose radicals.
On addition of an organic solvent in the polymerization system, the degree of grafting, the graft chain length and the apparent numbers of grafted chains were affected by the chain transfer of cellulose radicals to the solvent and the affinity with the monomer and cellulose. When NaIO4 was added in the AIBN polymerization system, the graft chain length decreased and the apparent numbers of grafted chains increased.View full abstractDownload PDF (388K) -
KUNIO MAKISHIMA1981 Volume 37 Issue 5 Pages P191-P197
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (663K) -
Noriko Choji, Isao Matsuura, Mikio Karasawa1981 Volume 37 Issue 5 Pages T192-T199
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSEquations for permeation through laminated composites (slabs) made by two components have been derived under the same conditions as in previous papers4, 5) in which the diffusion coefficient Di is constant and the equilibrium sorption Csi follows Henry's law in each component layer i.
Both the concentration distribution in the various laminated composites and permeation rate through them are calculated, by substituting Di and Csi of p-nitroaniline in each component film (nylon 6, cellulose diacetate, cellulose triacetate) into the equations. Good agreement is obtained between the calculations and experiments for the permeation in such systems.
Variations of over all diffusion coefficients (DPov, DLov) obtained by the permeation rate and time lag, respectively, are demonstrated against the volume fraction of a component in the composites. It is revealed that the DPov depends on only the volume fraction, whereas the DLov, depends on also the order of components in the composites.View full abstractDownload PDF (439K) -
Yoshiaki Shimizu, Mitsuo Kimura1981 Volume 37 Issue 5 Pages T200-T204
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe polarographic behavior of acid dye-protein complex was examined by the measurements of the polarograms of gelatin reacted with SNS and acid dye-protein (BSA, gelatin) systems.
The experimental fractional coefficients k with the calculated values of √D′/√D were compared as follows:
(1) k values of gelatin reacted with SNS and Orange 7-albumin complex were smaller than the calculated ones.
(2) k value of Orange 7-gelatin complex was larger than the calculated one.
(3) k value of HAS-albumin complex was close to the calculated one.
Probably these differences result from the following two factors:
(a) id increase with the increase of free dye in the diffusion layer.
(b) id decrease owing to the orientation process.View full abstractDownload PDF (290K) -
Kazushige Teraji, Tatsuo Homma1981 Volume 37 Issue 5 Pages T205-T212
Published: May 10, 1981
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSCurrently the fastness of dyeing is judged on the visual evaluation with the gray scales. However, it is impossible completely to avoid subjective judgement in this visual method. The results of the judgement often vary greatly depending on indivisual judges.
In the previous paper, the author had analyzed the gray scales using the depth value C* and shown that serial depth changes could be expressed by the proposed equation. For the extended use, the eauation becomes as follows.
where n=10-2N,
N: Nominal rating number,
KD: Criterion depth level constant. This leads the following equation to determine objectively the fastness rating of dyeing concerning staining. where KD is the criterion depth level in judgement of fastness and the value for gray scale is 0.125. However, it can be pointed out that in actual judgement, KD values which are much larger than 0.125 are used in almost all cases.
KD values calculated back from the results of visual judgement can be used to inspect the skilfulness of each judge and to search out the criterion depth level used unconsciously by judges.View full abstractDownload PDF (506K)
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