Also, fibers were mounted on cartridges for the S-4700 scanning electron microscope. These fibers were then carbonized but could not be tested because they were stuck together. The mechanical testing results for isotropic pitch are shown in Figures 3 and 4. Strength of isotropic pitch Figure 4. They could not be stabilized without adding a cross-linking agent to the precursor before melt spinning.
Further research needs to be done to decrease the cost of processing carbon fibers.