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Volume 1989, Issue 136
Displaying 1-7 of 7 articles from this issue
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Akira Kojima, Takeo Ote, Sugio Otani, Michiya Ota, Hideya Kurihara, Ei ...1989 Volume 1989 Issue 136 Pages 2-8
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSSurface modification of PAN based carbon fiber (CF) by cold plasma method was investigated to improve the high compatibility between CF and matrix in CF/carbon composites (C/C). The surface treatment of CF papers was carried out with O2-, Ar-, NH3- and CF4-cold plasma generated by radio wave (13.56 MHz). CFRP plate (2 mm in thickness) was prepared by laminating 40 sheets of the CF paper coated with phenolic resin, and carbonizing at 1000°C under nitrogen. These C/C plates showed the bulk density of 1.0 g/cm3 and the CF content of 40 vol%.
The C/C plates from CF paper treated in O2-, Ar- and NH3- cold plasmas yielded. 1.4-1.9 times higher values in mechanical strengths than those without plasma treat-ment. The flexural strength (67 MPa), Young's modulus (31 GPa) and the compressive strength (49 MPa) of C/C plates prepared from O2-cold plasma-treated CF, were the largest of all. The cold plasma treatment for CF is recommended as an ingenious method for the surface modification of CF.View full abstractDownload PDF (1186K) -
Akira Kojima, Sugio Otani, Koiti Nakamura, Shigeru Furukawa, Takeo Oht ...1989 Volume 1989 Issue 136 Pages 9-14
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe surface modification of PAN based carbon fiber (CF) was carried out with O2 or CF4 plasma generated by radio frequency (13.56 MHz) to obtain high compatibility between CF and matrix in CF paper/cement composites (CFRC). The wettability to water on CF surface was remarkably modified to hydrophilic by O2 plasma, and to hydrophobic by CF4 plasma. The CF paper after plasma treatment was used for the preparation of CFRC. CFRC plates (6 mm in thickness) were prepared by the lamination of 12 sheets of CF paper preimpregnated with portland cement paste (water/cement 0.4), and were cured in water. These CFRC's showed 1.5-1.8 g/cm3 in bulk density and 3.5 vol% in CF contents. The flexural strength of the CFRC plate prepared from O2 plasma-treated CF, was about 2.0 times higher (60 MPa) than that of CFRC without plasma treatment on CF. The CFRC plates prepared from CF paper pretreated in CF4 plasma, exibited 1.6 times higher (48 MPa) in flexural strength and 1.6 times larger in deflection com-pared with the CFRC from plasma-untreated CF. The fluoride ion transuded from CF4 plasma-treated CF surface, was interacted as the coupling agent between CF and portland cementhydrate. Therefore the cold plasma treatment on CF is regarded as strengthening of CFRC.View full abstractDownload PDF (1016K) -
M. Inagaki, Z.X. Bao, Y. Soneda1989 Volume 1989 Issue 136 Pages 15-20
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSNew type of ferric chloride-graphite intercalation compounds, which was characterized by new intercalate thickness d1 and new powder pattern of X-ray, was synthesized in chloroform solution. In the beginning of the reaction between graphite powder (average particle size of 400μm) and ferric chloride in chloroform, graphite intercalation com-pounds (GlCs) with d1-value of 9.4Å were formed, being the same in d1-value and X-ray powder pattern as those synthesized by vapor method and also in organic solutions and so being called as type I compounds in the present paper.
By continuation of reaction in chloroform, the type I compounds thus formed were found to convert to new type G1Cs, of which d1-value was supposed to be 11.8Å, much larger than that for the type I compounds, and X-ray powder pattern showed relatively strong two peaks around 26° in 2θ, different from that of the type I compound. The conversion from the type I to type II GlCs was found to occur when the weight ratio of FeCl3 to graphite was less than 2 and FeCl3 in 100 ml of CHCl3 was less than 2g. The identity period values observed, 21.8, 25.3, 28.6, 31.9 and 45.3Å, could be explained by stage change.View full abstractDownload PDF (872K) -
Takeshi Meguro, Akihide Kashiwagi, Naochika Torikai1989 Volume 1989 Issue 136 Pages 21-24
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSThe properties of iodine adsorption on activated carbons were investigated. The activated carbons were prepared from Yallourn brown coal char by activating with carbon dioxide under the conditions of chemical reaction rate-controlling step at 800°C in the atmosphere of PCO2, /PCO=9.0, 2.3 and 1.0, respectively. The iodine adsorption from an aqueous KI-I2 solution of 0.2 mol. of KI and 0.02 mol. of I2 per cubic decimeter was measured at 25°C for more than 120 hours. Dubinin-Radushkevich's equation was applied to elucidate the adsorption characteristics of activated carbons and a parameter Wo in the equation was estimated.
From these results, it is suggested that the micropore volume Wo increases with the decrease of PCO2/PCO ratio in the activation process of Yallourn brown coal char.View full abstractDownload PDF (624K) -
Relation with Optical Texture of MatrixM. Inagaki, M. Washiyama, M. Sakai1989 Volume 1989 Issue 136 Pages 25-28
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCrack propagation behaviour was observed in the matrix of carbon fiber/carbon composites under a polarized-light microscope and was discussed in the relationwith optical texture of the matrix.
The crack preferrentially propagates either through the boundaries betweenisotropic and surrounded well-oriented anisotropic regions or well-defined boundariesbetween isotropic and fine-mosaic anisotropic regions. The former boundary seems to becaused by stress graphitization due to large shrinkage of matrix of phenol resin and thelatter boundary by impregnation of pitch into pores formed by the carbonization of phenol resin matrix.View full abstractDownload PDF (1192K) -
Katsumi Yoshino, Hideki Ueno1989 Volume 1989 Issue 136 Pages 29-43
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSElectrical conductivity, thermoelectric power and plasma reflection of pyrolized polymer films of various molecular structures and intercalation effects on them are studied in detail, from which electronic transport process and electronic band scheme are discussed. Properties are found to be strongly related with the morphology of pre-polymers. For example, electro-chemically prepared PPV films demonstrate lower conductivity than that by chemical methods. Applications of spectral change of films associated with electro-chemical intercalation as a colour switching element are demonstrated.
The electrical conductivity of pyrolized bamboo tree is also discussed as a function of the heat-treated temperature. It is also demonstrated that various natural materials such as the skin of a prawn and chitosan etc can be also used successfully as pre-polymers for pyrolysis. Especially highly graphitized films are developed from cellulose films made by a biological method.View full abstractDownload PDF (1886K) -
[in Japanese], [in Japanese]1989 Volume 1989 Issue 136 Pages 44-56
Published: January 25, 1989
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1614K)
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