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Volume 38, Issue 12
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1982 Volume 38 Issue 12 Pages T562
Published: 1982
Released on J-STAGE: November 28, 2008
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Tooru Nogai, Motozoo Ihara1982 Volume 38 Issue 12 Pages T513-T516
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe effective thermal conductivity both perpendicular and parallel to fiber axes (the former is named perpendicular arrangement and the latter is named parallel arrangement) of unidirectionally oriented cotton fiber assembly was measured, and was discussed in terms of the model analyses presented in previous papers.1), 3) The results gave the following conclusions.
(1) The experimental results show that the effective thermal conductivity for both perpendicular arrangement and parallel arrangement of unidirectionally oriented fiber assembly falls with the increase of the volumetric ratio until it reaches a minimum value. And it rises with further increase of the volumetric ratio. However, the rate of rise is very little for the case of perpendicular arrangement, but is large for the case of parallel arrangement. The volumetric ratio at the minimum of the effective thermal conductivity for the parallel arrangement is lower than that for the perpendicular arrangement.
(2) The value of the effective thermal conductivity for the parallel arrangement is larger than that for the perpendicular arrangement. This is expected due to the difference of the radiative heat transfer between fibers and a plate from the model analyses prescribed in the previous papers.View full abstractDownload PDF (292K) -
Hiroshi Sakabe, Takeaki Miyamoto, Hiroshi Inagaki1982 Volume 38 Issue 12 Pages T517-T522
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThermal behavior of component proteins separated from wool keratin has been investigated in order to elucidate the endotherms in the differential thermal analysis (DTA) curves of wool fibers. For this purpose, the S-carboxymethylated keratin derived from wool was separated into the microfibrillar and the matrix proteins. The microfibrillar protein has further been fractionated into two fragments, i.e., a helix-rich and a non-helical fragment. Each protein film was prepared either by heating and/or stretching after casting from various solvents in order to vary the higher-order-structure. Three endotherms in a range of 200-300°C were observed in the DTA curves of the microfibrillar protein and the helix-rich fragment films cast from the aqueous solution. These endotherms were also found in the native wool fiber having so-called α-keratin structure. While, the matrix protein and the non-helical fragment films cast from aqueous solution exhibited only a broad endotherm in a range of 250-270°C.
The DTA curves of these samples were varied from each other according as the structural change of the higher-order of proteins induced a posteriori. These variations observed in the endotherms suggest that (i) the phase-transition temperatures observed for solubilized keratin proteins are much lower than those for wool fibers, (ii) the lowest temperature endotherm at about 220°C is due to the melting of the α-helix structure of microfibrillar proteins, (iii) the melting of the β-structure of microfibrillar and matrix proteins causes the endotherm in the range of 250-270°C, and (iv) the pyrolysis of non-helical proteins (i.e., matrix proteins and non-helical fragments) occurs at much lower temperature than that of α-helical proteins.View full abstractDownload PDF (1560K) -
Akira Takaku, Toshimasa Hashimoto, Shun Terui, Katsuo Miyazaki, Jiro S ...1982 Volume 38 Issue 12 Pages T523-T530
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe orientations of polyacrylonitrile crystallites and stacks formed with cyclized polymer chains on thermal stabilization have been investigated for acrylic fibers in relation with the length change during stabilization. There are two regions in the length change with heat treatment time. One is a change appearing in an initial period of heat treatment time, and the other is a change developed in the following period. The change in the initial period is mainly due to the relaxation on heating of the molecular orientation confined by the fiber-manufacturing process and shifts from shrinkage to extension with increasing applied stress during heat treatment. The length change appearing in the later period is observed mostly as shrinkage even under higher applied stresses during heat treatment and is considered to arise as a directional component parallel to the fiber axis of the volumetric shrinkage due to the stacking of the cyclized segments. The orientation of polyacrylonitrile crystallites changes in corresponding directly with the length change in the initial period of heat treatment. The orientation of the stacks of cyclized segments changes dependently on the variation of the orientation of polyacrylonitrile crystallites in the initial periods of heat treatment if the fibers are heat-treated under constant applied stresses. That is, if the fibers are heat-treated by keeping the orientation of polyacrylonitrile crystallites in a higher degree, the orientation of the stacks of cyclized segments gives a high value. The effect of applied stress during heat treatment on the orientation of the stacks of cyclized segments has been studied at different heat treatment temperature and time conditions which can be assumed equivalent mutually in respect of the shrinkage in free state. The effect of various applied stress cycles during heat treatment on the orientation of the stacks of cyclized segments has been also investigated.View full abstractDownload PDF (594K) -
KUNIO MAKISHIMA1982 Volume 38 Issue 12 Pages P529-P540
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
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Nobuya Kuroda, Nobuhiko Kuroki1982 Volume 38 Issue 12 Pages T531-T536
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe permeability of phenol in the amorphous region of polyester films which were crystallized by heat treatment at various temperatures, was measured as a function of phenol concentration and permeation temperature. The results are as follows.
The diffusion coefficient of phenol in the amorphous region is strongly dependent upon the concentration of phenol, and the dependency varies with the temperature at the heat treatment. Since every activation energy for the diffusion obtained here is almost equal to each other, it is proposed that the mechanism of the diffusion may not change with the heat treatment. The change of entropy for the sorption of phenol decreases with increase in the treatment temperature to 180°C, while it increases above 180°C.
From these results and the relation between the diffusion coefficient and the dynamic modulus for the same film measured in the phenol solution, it is suggested that the strain in some polymer chain of which both ends are fixed by crystallites increases with increase in the treatment temperature or crystallinity of the film, and that the other polymer chains having one free end remain without additional strain so that the diffusion becomes mainly to be controlled by the latter polymer chain.View full abstractDownload PDF (402K) -
Tokuhisa Miyarnatsu, Noboru Oguchi, Yoshihiko Kanchiku, Takanobu Aovag ...1982 Volume 38 Issue 12 Pages T537-T545
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSFibrous complex adsorbents for uranium extraction from sea water were prepared by introducing titanic acid or basic zinc carbonate as effective constituents into fibrous ion exchangers. A fibrous chelate type adsorbent was also tested. Among the adsorbents examined, the following ones demonstrated excellent properties for the recovery of uranium from sea water.
a) A fibrous, weakly acidic cation exchanger was treated with titanyl sulfate in aqueous sulfuric acid solution, which was followed by neutralization to afford a fibrous adsorbent containing titanic acid (QC-lf(Ti)). The adsorption capacity for uranium in sea water was estimated by extrapolation to be 50μg-U/g-Ad or 1170μg-U/g-Ti.
b) A fibrous, strongly acidic cation exchanger was treated in a similar way to afford another type of fibrous adsorbent with titanic acid incorporated (QCS-Ti). The adsorption capacity was estimated by extrapolation to be 20-30μg-U/g-Ad.View full abstractDownload PDF (1362K) -
Tokuhisa Miyamatsu, Zenichi Orito, Noboru Oguchi, Yoshihiko Tanaka, Yo ...1982 Volume 38 Issue 12 Pages T546-T553
Published: December 10, 1982
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThis paper describes the preparation and the characteristics of a fibrous adsorbent to recover uranium from sea water, The adsorbent was prepared by treating weakly acidic cation exchange fiber having carboxyl group with titanyl sulfate-sulfuric acid solution and subsequently with alkali. The results obtained are as follows:
1) When the fibrous adsorbent was treated with TiCl4/CH2Cl2 solution, the adsorptive capacity for uranium in sea water became 1.5-2 times higher than that of the untreated one: 77 μg-U/g-Ad or 640 μg-U/g-TiO2.
2) Uranium adsorption test was carried out with the fibrous adsorbent reinforced by polypropylene fiber in knitted form. The capacity was found to be 15 μg-U/g-Ad or 1.0 μg-U/cm2 for the soaking in sea water for 120h.
3) The reduction of the capacity after repeated use was observed, but the recovery was effected by soaking in dilute hydrochloric acid. Loss of titanic acid from the fiber was not considerable during the adsorption experiment.View full abstractDownload PDF (1310K)
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