STRUCTURE-PROPERTY RELATIONSHIPS OF PAN PRECURSOR FIBERS DURING THERMOOXIDATIVE STABILIZATION

Oxidative stabilization of polyacrylonitrile (PAN) precursor fibers is a vital step in producing carbon fibers. We have attempted to investigate changes in the mechanical properties and structure of the precursor fibers throughout this process. Wide-angle x-ray diffraction measurements, tensile properties, and SEM studies reveal the actual process of transformation of the original PAN structure to the ladder polymer. The crystalline structure transforms to the amorphous phase during the stabilization process. Structural transformation also results in a considerable drop in mechanical properties.