Carbonization of fractionated pitches under pressure

✍ Scribed by M. Inagaki; K. Kuroda; M. Sakai; E. Yasuda; S. Kimura

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 386 KB
• Volume: 22
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(84)90003-4

✦ Synopsis

Seven fractions of a coal tar pitch having different molecular weights were carbonized up to 650°C under a pressure of 30 MPa in closed and open gold tubes. Carbon yield and microscopic texture of the resultant products were investigated. The graphitizability was evaluated through measurements of interlayer spacing and crystallite size after heat treatment at 3000°C. Carbons prepared from benzenesoluble fractions showed a coarse mosaic texture and high graphitizability, while the carbon yield depended not only on the molecular weight of the fraction but also on the condition of carbonization. The benzene-insoluble/pyridine-soluble fraction led to an isotropic texture and a small value of the crystallite size under the open system, but to a coarse flow-type texture and a high graphitizability under the closed system. A similar trend was observed more remarkably for the pyridine-insoluble fraction. The carbon yield of the original pitch was found to be a weighted sum of those of the constituent fractions. The nresence of low molecular weieht fractions seemed to have a strong effect on the texture of the resultant carbons, particularly under the closed system.