Mesophase fibrous-domain

There is a close relation between the proton spin lattice relaxation time (Tj) observed with pulsed NMR at room temperature (8, 9) and the microstructure of mesophase (8) transformed from the parent matrix of coal. That is, the longer the relaxation time is, the more sufficient the growth of mesophase from the matrix occurs, and shown in Table II. The parent materials, which give the fibrous-domain texture at the early stages of carbonization, have the longest relaxation time found so far, as described in the table. 

We may conclude from the results above that the materials that give fibrous-domain mesophase on heating show a narrowing of the NMR... 

Figure 5 presents the results of tensile tests for the HPC/OSL blends prepared by solvent-casting and extrusion. All of the fabrication methods result in a tremendous increase in modulus up to a lignin content of ca. 15 wt.%. This can be attributed to the Tg elevation of the amorphous HPC/OSL phase leading to increasingly glassy response. Of particular interest is the tensile strength of these materials. As is shown, there is essentially no improvement in this parameter for the solvent cast blends, but a tremendous increase is observed for the injection molded blend. Qualitatively, this behavior is best modeled by the presence of oriented chains, or mesophase superstructure, dispersed in an amorphous matrix comprised of the compatible HPC/OSL component. The presence of this fibrous structure in the injection molded samples is confirmed by SEM analysis of the freeze-fracture surface (Figure 6). This structure is not present in the solvent cast blends, although evidence of globular domains remain in both of these blends appearing somewhat more coalesced in the pyridine cast material.

The optically anisotropic textures of mesophase from the samples heat-treated at the early stages of carbonization are classified into five types corresponding to isotropic, fine mosaic, coarse mosaic, fibrous, and domain. 

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