Correlation between molecular stacking and anisotropic texture in spinnable mesophase pitch

The correlation of the anisotropic texture and (002) the molecular stacking property of spinnable mesophase pitch (SMP) was closely examined. SMP was found to be a specific solution consisting of mesogenic and solvent components, and the mesogenic component was composed of a cluster unit of (002) stacked molecular sheets. The anisotropic texture of SMP was strongly correlated with the height of (002) molecular stacking. When the concentration ratio of the mesogenic component to the solvent component was higher than the threshold concentration, the SMP always had 100 vol% anisotropic texture and a similar or larger number of stacked (002) sheets compared with its mesogenic component in both the solid and molten states. The solvent component, in both lamellar and hexagonal phases, assisted orientation of mesogenic molecules and rearrangement of mesogenic cluster units, thereby inducing a higher degree of graphitization than that of the solvent-free mesophase pitch. A schematic phase model of SMP was proposed based on a lyotropic liquid crystalline system and a hierarchical domain model.