Characterization of the Phases in Centrifuged Mesophase Pitches

Abstract
Mesophase pitches derived from petroleum, coal tar, and naphthalene have been separated into their isotropic and anisotropic phases by high-temperature centrifugation. The separated phases have been characterized by determining their elemental constitutions, densities, solubilities, glass transition temperatures, molecular weight distributions, and X-ray and EPR spectra. The data demonstrate the sensitivity of mesophase formation in carbonaceous pitches to molecular structure and distribution.