mesophase pitch

https://doi.org/10.1351/goldbook.M03850
A @P04677@ with a complex mixture of numerous essentially aromatic @H02889@ containing anisotropic liquid-crystalline particles (@C00822@) detectable by optical microscopy and capable of coalescence into the @B00754@.
Note:
The @C00822@ particles are formed from the aromatics of high molecular mass in @M03841@, which have not yet been aggregated to particles detectable by optical microscopy within the apparently @I03353@ @P04677@ matrix. The @C00822@ is insoluble in quinoline and pyridine, but the amount of @M03849@ measured from microscopical observation appears somewhat higher because parts of the @C00822@ can be extracted by the solvents.
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 496 [Terms] [Paper]