Carbonization of pitches—IV: Carbonization of polycyclic aromatic hydrocarbons under the presence of aluminum chloride catalyst

✍ Scribed by Isao Mochida; Keiko Kudo; Noriyoshi Fukuda; Kenjiro Takeshita; Ryohei Takahashi

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 831 KB
• Volume: 13
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(75)90270-5

✦ Synopsis

Using aluminum chloride as a catalyst, polycyclic aromatic hydrocarbons were converted into carbons of two different structures, although at the early stage all carbonization processes proceeded via molten phase. The structures were examined with an optieal microscope under crossed nicols. The firs1 type of structure was a flow pattern with large oriented needle like domains observed for carbons obtained from naphthalene, chrysene, and anthracene, whereas the second one was a mosaic structure for carbon from pyrene. A significant subsequent graphitization at 2500°C (as expressed by L, ) took place for both types regardless of the different size of oriented domains. The orientation of domains depends on the rate of carbonization controlled by the holding temperature, time and quantity of the catalyst. Appropriate conditions of carbonization suppressing too fast generation of nuclei so as to permit the formation of ordered arrangement of condensed molecules were found to yield a needle-like coke also from pyrene, thus showing that the passing through a molten phase is not a sufficient condition for formation of a needle-like structure.