Mesophase spheres were selectively prepared from petroleum A240, hydrotreated A240, and coal tar pitches by heat treatment at 430 degree C for 1 h under vacuum (5-10 Torr), the sphere content being as high as 55 vol% in the residual product. Mesophase spheres from A240 and coal tar pitch tended to coalesce as bulk mesophase of irregular shape when heat-treated for the longer time of 3 H. In contrast, spherical shapes of larger diameter were maintained when hydrotreated A240 was heated under the same conditions where the sphere content was 70 vol%. The spheres were separated by pyridine extraction.
|Number of pages
|High Temperatures - High Pressures
|Published - 1984
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Physical and Theoretical Chemistry