炭素
Online ISSN : 1884-5495
Print ISSN : 0371-5345
ISSN-L : 0371-5345
1988 巻, 135 号
選択された号の論文の10件中1~10を表示しています
  • 1988 年 1988 巻 135 号 p. 9a
    発行日: 1988年
    公開日: 2011/03/01
    ジャーナル フリー
  • 1988 年 1988 巻 135 号 p. 9b
    発行日: 1988年
    公開日: 2011/03/01
    ジャーナル フリー
  • 安斎 正博, 山田 泰弘, 萩原 茂示, 大蔵 明光
    1988 年 1988 巻 135 号 p. 239-246
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    The carbon fibers, the surface of which was hydrogenated and oxidized, were sub-mitted to be examined concerning the effect of the surface structure of carbon fiber on the strength of C/C composite. After the sizing agent on carbon fiber surface was first removed by boiling with ethyl methyl ketone, the surface was hydrogenated with H2 at 1000°C and further the surface hydrogenated was oxidized with aqueous H2O2 solution at the boiling temperature for various hours respectively. The amount of surface oxides, in this case, was measured by means of alkali titration, on the assumption that the surface oxides belong to the acidic groups such as hydroxyls, carboxyls and so on. The tensile strength of carbon fibers barely changed through such chemical surface modifications. It was found that the bending strength of C/C composites, in which the carbon fibers had been used as a reinforcing filler, linearly increased with an increase in the amount of surface acidity, that is, the surface acidic sites played a major role in the increase of the bending strength of C/C composite.
    Such effects of surface oxides could be ascribed to the strong adhesion between the fiber surface and the binder in the first stage and the following formation of C-C bond between the fiber surface and the binder the pyrolysis of surface oxides, during the molding of composite by means of hot-pressing.
  • 米本 年邦, 福島 龍太郎, 只木 貞力
    1988 年 1988 巻 135 号 p. 247-253
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    Mesophase petroleum pitch fiber was oxidized by two kinds of mixed gases of O2 and N2 and oxygen consumption rates were measured under several isothermal conditions between 160°C and 240°C. Oxidized pitch fiber obtained was carbonized to evaluate its infusibility and also analyzed to examine its elemental composition and structure change during the reaction by using several instrumental analytical method such as elemental analysis, electron spectroscopy for chemical analysis and fourier transform infrared analysis.
    It was found that 4/3 mole of oxygen atom is fixed in the fiber and 2/3 mole of water is released during the consumption of one mole of oxygen gas. Both of total amount of oxygen consumed and elemental compositions of carbon, hydrogen and oxygen were found to be constant at completion of the stabilization reaction under any experimental condition conducted.
    It can be concluded that concentration of the fixed oxygen in the surface layer of the fiber is different from that in the inner region. It can also be assumed that the active site in the molecules that constitute pitch fiber is aliphatic chain and that oxidation reaction proceed with forming of carbonyl group.
  • 化学反応律速条件での賦活と微細孔隙構造の発達
    目黒 竹司, 岡本 光弘, 木村 喜一, 鳥飼 直親
    1988 年 1988 巻 135 号 p. 254-260
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    The influence of reaction rates on the development of micropore structure of chars in the activation process under the chemical reaction controlling region was studied. The char sample was prepared from Yallourn brown coal, in the size of 10 to 20 mesh, by carboniz- ing in nitrogen stream up to 850°C with a heating rate of 1°C/min. The activation reaction of char sample was carried out at 800°C in the atmospheres of (PCO2/PCO) =9.0, 2.3 and 1.0, respectively. From the results of porosity vs. burn-offs, the activation reaction carried out at (Pco2/Pco) =2.3 and 1.0 was found to be in good agreement with chemical reaction controlling condition. However, the reaction carried out at (Pco2/Pco) =9.0 was seemed to have been affected by in-pore diffusion. The pore size distributions of these activated samples were calculated from isotherms of methanol vapor adsorption at 50°C, and micropore volume and transitional pore volume of samples were compared with each other. Dubinin-Astakhov's equation was found to be applicable to isotherms of carbon dioxide adsorption at 20°C, and parameters, such as W0, E and n, were estimated. As the results, it was proved that micropore volume and parameter W0 of samples increased with de-creasing the partial pressure of CO2 in (PCO2/PCO).
  • Satoru Nishioka, Akihiro Demura, Hirokazu Oda, Chikao Yokokawa
    1988 年 1988 巻 135 号 p. 261-266
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    Five kinds of coals of different ranks (C%78-91) and four kinds of wood (a kind of bamboo, Zelkova, Ebony and Mangrove) were heat-treated under different heating-patterns up to 873 and/or 1, 273 K. The heating-rate employed was 5, 50 or 100 K/min. and it was varied in the course of pyrolysis in several different patterns. The carbons of different history thus obtained were submitted to determination of their pore-size distribution. It was found that the heating-pattern had a marked effect controlling the pore-structure of carbons and also that the effect varied appreciably with the varieties of the materials and of their history.
  • 杉浦 勉, 飯島 孝, 佐藤 真樹, 藤本 研一
    1988 年 1988 巻 135 号 p. 267-274
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    Graphite intercalation compounds (GICs) using pitch-based carbon fibers and copper chloride are expected to be applied as light-weight conductive materials because of their high conductivity and considerable stability. In this study, reaction conditions, electrical resistivity and mechanical properties are discussed.
    A small amount of FeCl3 added speeds this reaction up remarkably. The role of FeCl3 is to decrease activation energy, that is, to accelerate the reaction. This catalytic effect is observed both in the cases of pitch-based carbon fibers and sheet-like graphite, although reaction rate is largely affected by the shapes of host graphite. When pitch-based carbon fibers (P120X) are used as host materials, the addition of FeCl3 makes reaction time short from 16 hours to 2 hours, whereas reaction for 30 days was reduced to 5 days by the addition in the case of sheet-like graphite.
    Resistivity of metal-chloride intercalated graphite depends on that of the pristine host materials and the amount of the intercalate. Mechanical properties such as tensile strength, Young's modulus and elongation decrease in accordance with process of intercalation. Degradation of mechanical properties is recovered by thermal de-intercalation, which indicates that the structure of graphite is not destroyed by intercalation nor de-inter-calation reaction.
  • 安田 榮一, 田辺 靖博, 町野 洋, 木村 脩七
    1988 年 1988 巻 135 号 p. 275-277
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    Unidirectional reinforced CFRP, whose matrix was polyfurfural resin (furan resin), were prepared with different two types of carbon fibers. Thermal expansion behaviours of the CFRPs during carbonization process were examined precisely.
    It was assumed that the matrix precursor resin was deformed during carbonization process by the stress which was caused from the thermal expansion or shrinkage difference between the matrix and the fiber, and then the structure of the matrix after carbonization might change in the observation of thermo mechanical property and raman spectrum.
  • 安斎 正博, 大蔵 明光
    1988 年 1988 巻 135 号 p. 278-285
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
    It is attempted to produce high strength carbon matrix composite from fine pulverized coke, mesophase coal tar pitch and SiC whisker.
    The fabrication method of SiC whisker/carbon composite in this study is as follows: the pulverized coke and SiC whisker are mixed with the mesophase coal tar pitch, which are directly turned to SiC whisker/carbon composite by hot press (650°C, 20MPa) and heat-treatment at various temperature so as to get a high density and high strength. The maximum bending strength of the composite reinforced with 40Wt% of SiC whisker was 120MPa, and the strength value was remarkably high in comparison with 80MPa of the product without reinforcing under similar preparation conditions. In particular, it is noteworthy that the graphitization of the carbon matrix in the SiC whisker/carbon com-posite is more significantly accelerated than that in the absence of SiC whisker by heat-treatment at 2000°C or above.
  • 高津 英幸, 奥 達雄
    1988 年 1988 巻 135 号 p. 286-309
    発行日: 1988/10/25
    公開日: 2010/06/28
    ジャーナル フリー
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