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45. Mesophase formation from different pitches: texture characterization, magnetic anisotropy and rheological properties
208
Abstracts
alescence and any possible structural reordering of mesophase during carbonization is primarily responsible for the optical texture of the final carbon. Hot stage microscopy, with video recording, has been used to follow the growth of mesophase, particularly the effects of inert material and spatial restrictions. 43. Pressure-temperature microscopy of petroleumderived hydrocarbons A. J. Perrotta, J. P. McCullough and Harold Beuther (Gulf Research & Development Company, P.O. Drawer 2038, Pittsburgh, PA 15230 U.S.A.). A gas flow pressure-temperature microscope has been designed and constructed for direct observations of heavy hydrocarbons and catalysts at hydrogen pressures to 1.38 x 107Pa (2OOOpsig) and 600°C. An air-blown decant oil derived hydrocarbon crystallizes rapidly to a cryptocrystalline birefringent phase at low pressures of hydrogen less than 6.90 x 106P a (1000 psig) and at nitrogen pressures to 1.31 x 10’ Pa (1900 psig). At hydrogen pressures greater than 6.90 x lo6 Pa (1000 psig), mesophase is formed quite easily over similar time periods. Mesophase formation at the lower hydrogen pressure occurs without much movement of individual spheroids and coalescence to larger mesophase crystals occurs with nearest neighbors. At higher hydrogen pressures, mesophase spheroids are much more mobile, and coalescence occurs by random collision of rapidly moving spheroids in a more fluid medium. Comparative crystallization behavior is given for the pyrolyzate from the same decant oil pyrolyzed in flowing nitrogen. 44. Problems in mesophase observation using hot stage S. Uemura, T. Hirose, H. Takashima, 0. Kato and M. Harakawa (Nippon Oil Company, Ltd., Central Technical Naka-ku,
Research Laboratory, 8, Chidori-cho, Yokohama, Japan). Mesophase-forming
behaviors were observed for several pitches using hot stage. Some pitches (e.g. refined naphtha tar pitch) showed as similar behavior as in large-scale carbonizing system, but others (e.g. coal tar pitch) showed quite different behavior. The correlation between the mesophase-forming behavior of pitch and its chemical structure is discussed. 45. Mesophase formation from different pitches: texture characterization, magnetic anisotropy and rheological properties F. Keoury, H. Gasparoux, P. Delhaes and F. Albugues and Y. Grenie (Centre de Recherche Paul Pascal, Domaine Universitaire, C.N.R.S. 33405 Taleme, France). Petroleum pitch and three coal tar
pitches have been investigated applying the methodology previously described for acenaphtylene mesophase studies. The existence diagram, the mesophase texture observed in situ by optical microscopy, the diamagnetic anisotropy on oriented mesophase, the temperature dependence of the apparent viscosity
coefficient, and also the graphitization be reported and compared.
process, will
46. Microstructure of mesophase formed in a magnetic field Y. Yamada, M. Shiraishi and T. Yamakawa (National Research Institute for Pollution and Resources, Yatabe, Zbarai, 305 Japan). Microstructure of meso-
phase from Ashland and acenaphthylene pitches heat-treated in a magnetic field of lT(10 kG) was investigated by a transmission electron microscope and X-ray diffraction. The layer alignment in mesophase texture is microscopically the almost same as the behavior in the absence of the field, but longrange orientation is promoted by the field. 47. Asphalts as studied by optical microscopy, transmission electron microscopy and X-ray diffraction X. Bourrat and A. Oberlin (Laboratoire Marcel Mathieu, ER 131 du CNRS, UER Sciences, 45046 Orleans Cedex, France). Asphalts were extracted from various crude oils (0.86
creasingly heavier solvents (nC,, nC, and nC,). Structures and textures obtained after heat-treatment were studied by optical microscopy (to 46&49O”C), TEM and X-ray diffraction (100@29OO”C). The extent of optical anisotropy and local molecular orientation and the ability to graphitize are related to heteratom behaviour (H, 0, N, S). Heat-treatment is shown to be a good method for characterizing asphaltenes and crude oils. 48. Characterizations by analytical and textural observations in the carbonization process of carbon mixtures A. Kotato and M. Kurata (Zbaraki Research Laboratory, Hitachi Chemical Co. Ltd., Hitachi, Ibaraki, 326, Japan). This paper deals with the carbonization
process of binder pitch with filler material and relations between the carbonization process and some properties of the resultant carbon product. The mixtures of pitch and filler were heated to the prefixed temperatures, observed by the polarized light microscope and analyzed by solvent extractions. 49. Nonequilibrium disclinations in the carbonaceous mesophase M. Buechler, C. B. Ng and J. L. White (Materials Sciences Laboratory, The Aerospace Corporation, P.O. Box 929.57, Los Angeles, CA 90009, U.S.A.).
Disclination reactions in carbonaceous mesophase have been observed directly by polarized light on the free surface of petroleum pitch during pyrolysis. Structural sketches of specimens quenched from critical stages in such reactions reveal that freshly formed disclinations can appear in forms appreciably distorted from the equilibrium structures of wedge disclinations. 50. Mesophase formation within carbon fiber bundles J. L. White, P. M. Sheaffer, C. B. Ng and M. Buechler (Materials Sciences Laboratory, The Aero-
Abstracts
alescence and any possible structural reordering of mesophase during carbonization is primarily responsible for the optical texture of the final carbon. Hot stage microscopy, with video recording, has been used to follow the growth of mesophase, particularly the effects of inert material and spatial restrictions. 43. Pressure-temperature microscopy of petroleumderived hydrocarbons A. J. Perrotta, J. P. McCullough and Harold Beuther (Gulf Research & Development Company, P.O. Drawer 2038, Pittsburgh, PA 15230 U.S.A.). A gas flow pressure-temperature microscope has been designed and constructed for direct observations of heavy hydrocarbons and catalysts at hydrogen pressures to 1.38 x 107Pa (2OOOpsig) and 600°C. An air-blown decant oil derived hydrocarbon crystallizes rapidly to a cryptocrystalline birefringent phase at low pressures of hydrogen less than 6.90 x 106P a (1000 psig) and at nitrogen pressures to 1.31 x 10’ Pa (1900 psig). At hydrogen pressures greater than 6.90 x lo6 Pa (1000 psig), mesophase is formed quite easily over similar time periods. Mesophase formation at the lower hydrogen pressure occurs without much movement of individual spheroids and coalescence to larger mesophase crystals occurs with nearest neighbors. At higher hydrogen pressures, mesophase spheroids are much more mobile, and coalescence occurs by random collision of rapidly moving spheroids in a more fluid medium. Comparative crystallization behavior is given for the pyrolyzate from the same decant oil pyrolyzed in flowing nitrogen. 44. Problems in mesophase observation using hot stage S. Uemura, T. Hirose, H. Takashima, 0. Kato and M. Harakawa (Nippon Oil Company, Ltd., Central Technical Naka-ku,
Research Laboratory, 8, Chidori-cho, Yokohama, Japan). Mesophase-forming
behaviors were observed for several pitches using hot stage. Some pitches (e.g. refined naphtha tar pitch) showed as similar behavior as in large-scale carbonizing system, but others (e.g. coal tar pitch) showed quite different behavior. The correlation between the mesophase-forming behavior of pitch and its chemical structure is discussed. 45. Mesophase formation from different pitches: texture characterization, magnetic anisotropy and rheological properties F. Keoury, H. Gasparoux, P. Delhaes and F. Albugues and Y. Grenie (Centre de Recherche Paul Pascal, Domaine Universitaire, C.N.R.S. 33405 Taleme, France). Petroleum pitch and three coal tar
pitches have been investigated applying the methodology previously described for acenaphtylene mesophase studies. The existence diagram, the mesophase texture observed in situ by optical microscopy, the diamagnetic anisotropy on oriented mesophase, the temperature dependence of the apparent viscosity
coefficient, and also the graphitization be reported and compared.
process, will
46. Microstructure of mesophase formed in a magnetic field Y. Yamada, M. Shiraishi and T. Yamakawa (National Research Institute for Pollution and Resources, Yatabe, Zbarai, 305 Japan). Microstructure of meso-
phase from Ashland and acenaphthylene pitches heat-treated in a magnetic field of lT(10 kG) was investigated by a transmission electron microscope and X-ray diffraction. The layer alignment in mesophase texture is microscopically the almost same as the behavior in the absence of the field, but longrange orientation is promoted by the field. 47. Asphalts as studied by optical microscopy, transmission electron microscopy and X-ray diffraction X. Bourrat and A. Oberlin (Laboratoire Marcel Mathieu, ER 131 du CNRS, UER Sciences, 45046 Orleans Cedex, France). Asphalts were extracted from various crude oils (0.86
creasingly heavier solvents (nC,, nC, and nC,). Structures and textures obtained after heat-treatment were studied by optical microscopy (to 46&49O”C), TEM and X-ray diffraction (100@29OO”C). The extent of optical anisotropy and local molecular orientation and the ability to graphitize are related to heteratom behaviour (H, 0, N, S). Heat-treatment is shown to be a good method for characterizing asphaltenes and crude oils. 48. Characterizations by analytical and textural observations in the carbonization process of carbon mixtures A. Kotato and M. Kurata (Zbaraki Research Laboratory, Hitachi Chemical Co. Ltd., Hitachi, Ibaraki, 326, Japan). This paper deals with the carbonization
process of binder pitch with filler material and relations between the carbonization process and some properties of the resultant carbon product. The mixtures of pitch and filler were heated to the prefixed temperatures, observed by the polarized light microscope and analyzed by solvent extractions. 49. Nonequilibrium disclinations in the carbonaceous mesophase M. Buechler, C. B. Ng and J. L. White (Materials Sciences Laboratory, The Aerospace Corporation, P.O. Box 929.57, Los Angeles, CA 90009, U.S.A.).
Disclination reactions in carbonaceous mesophase have been observed directly by polarized light on the free surface of petroleum pitch during pyrolysis. Structural sketches of specimens quenched from critical stages in such reactions reveal that freshly formed disclinations can appear in forms appreciably distorted from the equilibrium structures of wedge disclinations. 50. Mesophase formation within carbon fiber bundles J. L. White, P. M. Sheaffer, C. B. Ng and M. Buechler (Materials Sciences Laboratory, The Aero-