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21. Solubility and reactivity of carbonaceous mesophase
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Abstracts carbon/carbon matrices and bulk graphites. In this paper, the basic concepts of solubility theory will be briefly explored and used to postulate the existence of a “gradient” solution model for pitch. The results of various extraction conditions on the actual characteristics of the extracted products will also be discussed. Examples of how these extracted products perform as precursors for carbon fiber will be shown. lg. Phase behavior of mesomorphic binary systems R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.). ‘The phase diagrams for binary mesomorphic systems with differing miscibilities will be presented. Phase behavior with rod and discotic mesophases will also be discussed. The concepts developed are generalized to describe mesophase pitches as a pseudo binary system between a mesogen and a nonmesogen. 19. Mesophase formation in polynuclear aromatic compounds S-H. Chen and R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Inforstitute, Troy, NY 12181, U.S.A.). Mesophase mation in the parapolyphenylene system was studied by hot stage microscopy and differential scanning calorimetry (DSC). Phase diagrams were constructed to derive the virtual mesophase-isotropic transition temperatures of the non-mesomorphic para-quater and terphenyl. The possibility of mesophase formation for a mixture of disc-like molecules was also investigated. 20. Pitch-mesophase-carbon transformation diagrams B. Rand and S. Whitehouse (Department of Ceramics, Glasses and Polymers, University of Shefield, Shefield SlO 2TZ, England). The concept of a transformation diagram to describe the pyrolysis of pitch to carbon via mesophase is outlined and experimental results presented. The diagram is constructed from characteristic temperatures such as temperatures of decomposition and glass transition temperatures of the different phases present plotted as some function of the extent of transformation to carbon such as C/H atomic ratio. 21. Solubility and reactivity of carbonaceous mesophase lsao Mochida, Keiko Maeda, Yozo Korai (Research institute of Industrial Science, Kyushu University, Kasuga 816, Japan). Solubilities and reactives of carbonaceous mesophases, which were prepared under variable conditions, were investigated in the co-carbonization with some additives. The solubility and reactivity are strongly independent upon the natures of mesophase as well as the additives. The mesophase produced at lower temperature consisting of lower molecular weight components are more soluble and reactive. The importance of hydrogen
transfer from the additive is another ture for the better solubility.
important
fea-
22. Volatilized compounds and microstructural development during mesophase growth in a pitch fraction I. W. Sorensen? and R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.). The tolueneinsoluble fraction of Ashland A-240 pitch was subjected to controlled heating in vacuum and argon. Material evolved and condensed in cooler parts of the furnace was removed and studied by HPLC. The observation of distinct chromatographic peaks was correlated with mesophase development within the pitch and independent studies on the fraction’s composition.
TPresently with Bendix Advanced Technology Center, Columbia, MD.
23. Anisotropic/isotropic coke precursors in decant oil E. W. Albaugh, J. D. Bacha, H. T. Best, W. E. Hartman, R. M. Henry, and K. S. Seshadri (Gulf Research & Development Company, P.O. Drawer 2038, Pittsburgh, PA 15320, U.S.A.) and G. B. Engle and R. J. Price (GA Technologies Inc., P.O. Box 81608, San Diego, CA 92138, U.S.A.). The chemical structural characteristics and pyrolytic behavior of preparative-scale liquid chromatographic fractions of a decant oil were correlated. Only those fractions containing condensed aromatics bearing few alkyl substituents or polar groups formed mesophase and anisotropic cokes. Fractions rich in highly alkylated aromatics or polar compounds failed to form mesophase and yielded isotropic cokes. 24. Mesophase formation from characterized pitch fractions (Part 2) E. Fitzer, C. Holley, L. Liu, T. Trendelenburg (Institut .fiir Chemische Technik, Universitat Karls12, 7500 Karlsruhe, FRG). ruhe, KaiserstaPe Pitches from various origins were fractionated by subsequential extraction and characterized. The mesophase formation behaviour was studied using classical optical and in-situ hot stage methods. These results are correlated with the analytical data. 25. Aromatic asphaltenes Part I. Asphaltenes of aromatic pitches Ghaz Dickakian (Exxon Enterprises, Greenville, South Carolina; Exxon Chemical Company, Florham Park, New Jersey, U.S.A.). Three highly aromatic pitches derived from petroleum (catalytic cracking residue), chemical (steam cracking residue) and coal (coal gasification) were fractionated by solvent extraction into C,-asphaltene and a deasphaltenated oil (DAO). The C,-asphaltene and the DA0 fractions were characterized (NMR, high-temperature GPC, coking
Abstracts carbon/carbon matrices and bulk graphites. In this paper, the basic concepts of solubility theory will be briefly explored and used to postulate the existence of a “gradient” solution model for pitch. The results of various extraction conditions on the actual characteristics of the extracted products will also be discussed. Examples of how these extracted products perform as precursors for carbon fiber will be shown. lg. Phase behavior of mesomorphic binary systems R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.). ‘The phase diagrams for binary mesomorphic systems with differing miscibilities will be presented. Phase behavior with rod and discotic mesophases will also be discussed. The concepts developed are generalized to describe mesophase pitches as a pseudo binary system between a mesogen and a nonmesogen. 19. Mesophase formation in polynuclear aromatic compounds S-H. Chen and R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Inforstitute, Troy, NY 12181, U.S.A.). Mesophase mation in the parapolyphenylene system was studied by hot stage microscopy and differential scanning calorimetry (DSC). Phase diagrams were constructed to derive the virtual mesophase-isotropic transition temperatures of the non-mesomorphic para-quater and terphenyl. The possibility of mesophase formation for a mixture of disc-like molecules was also investigated. 20. Pitch-mesophase-carbon transformation diagrams B. Rand and S. Whitehouse (Department of Ceramics, Glasses and Polymers, University of Shefield, Shefield SlO 2TZ, England). The concept of a transformation diagram to describe the pyrolysis of pitch to carbon via mesophase is outlined and experimental results presented. The diagram is constructed from characteristic temperatures such as temperatures of decomposition and glass transition temperatures of the different phases present plotted as some function of the extent of transformation to carbon such as C/H atomic ratio. 21. Solubility and reactivity of carbonaceous mesophase lsao Mochida, Keiko Maeda, Yozo Korai (Research institute of Industrial Science, Kyushu University, Kasuga 816, Japan). Solubilities and reactives of carbonaceous mesophases, which were prepared under variable conditions, were investigated in the co-carbonization with some additives. The solubility and reactivity are strongly independent upon the natures of mesophase as well as the additives. The mesophase produced at lower temperature consisting of lower molecular weight components are more soluble and reactive. The importance of hydrogen
transfer from the additive is another ture for the better solubility.
important
fea-
22. Volatilized compounds and microstructural development during mesophase growth in a pitch fraction I. W. Sorensen? and R. J. Diefendorf (Materials Engineering Department, Rensselaer Polytechnic Institute, Troy, NY 12181, U.S.A.). The tolueneinsoluble fraction of Ashland A-240 pitch was subjected to controlled heating in vacuum and argon. Material evolved and condensed in cooler parts of the furnace was removed and studied by HPLC. The observation of distinct chromatographic peaks was correlated with mesophase development within the pitch and independent studies on the fraction’s composition.
TPresently with Bendix Advanced Technology Center, Columbia, MD.
23. Anisotropic/isotropic coke precursors in decant oil E. W. Albaugh, J. D. Bacha, H. T. Best, W. E. Hartman, R. M. Henry, and K. S. Seshadri (Gulf Research & Development Company, P.O. Drawer 2038, Pittsburgh, PA 15320, U.S.A.) and G. B. Engle and R. J. Price (GA Technologies Inc., P.O. Box 81608, San Diego, CA 92138, U.S.A.). The chemical structural characteristics and pyrolytic behavior of preparative-scale liquid chromatographic fractions of a decant oil were correlated. Only those fractions containing condensed aromatics bearing few alkyl substituents or polar groups formed mesophase and anisotropic cokes. Fractions rich in highly alkylated aromatics or polar compounds failed to form mesophase and yielded isotropic cokes. 24. Mesophase formation from characterized pitch fractions (Part 2) E. Fitzer, C. Holley, L. Liu, T. Trendelenburg (Institut .fiir Chemische Technik, Universitat Karls12, 7500 Karlsruhe, FRG). ruhe, KaiserstaPe Pitches from various origins were fractionated by subsequential extraction and characterized. The mesophase formation behaviour was studied using classical optical and in-situ hot stage methods. These results are correlated with the analytical data. 25. Aromatic asphaltenes Part I. Asphaltenes of aromatic pitches Ghaz Dickakian (Exxon Enterprises, Greenville, South Carolina; Exxon Chemical Company, Florham Park, New Jersey, U.S.A.). Three highly aromatic pitches derived from petroleum (catalytic cracking residue), chemical (steam cracking residue) and coal (coal gasification) were fractionated by solvent extraction into C,-asphaltene and a deasphaltenated oil (DAO). The C,-asphaltene and the DA0 fractions were characterized (NMR, high-temperature GPC, coking