Tensile properties of intercalated pitch mesophase carbon fibers

The effects of intercalation with Br (residue) or CuCl 2 on the diameters d, microstructures, Young's moduli E, tensile strengths S and electrical conductivities of P-100 and P-120 fibers were determined using single filament methods. Circular cross section P-100, with an uncracked radial transverse texture, developed small axial cavities and longitudinal surface cracks on CuCl 2 intercalation, whereas the elliptical P-120 fibers with a “Pan Am” texture became more circular without evident damage on bromination. E decreases of 18% (P-120/Br) and 39% (P-100/CuCl 2 ) resulted from mean d increases of ≤ 11% and 28% respectively, which also contributed to a ∼ 38% decrease in mean S at 1 cm gage length in both cases. The gage length dependence of S increased for P-100 and decreased for P-120 due to changes in flaw distribution which depended on fiber and intercalant type.