EFFECT OF DRAW RATIO ON THE STRUCTURE AND THE THERMOCHEMICAL PROPERTIES OF ELECTROSPUN POLYACRYLONITRILE NANOFIBERS

摘要

In comparison with the conventional microfibers, electrospun PAN nanofibers (ENFs) have evident advantages on the crystallinities and morphologies due to their ultra-slim diameters, which is the foundation for preparing carbon fibers with superior mechanical properties. Establishing a reasonable procedure for the preparation of ENFs is the key to produce high quality precursor fibers. However, limited effort has been devoted in this research field. Particularly, although post-spinning drawing process can significantly improve the degree of crystallinity and orientation, the effects of draw ratio on the structure and the thermochemical properties of precursor nanofibers are still unclear and require further investigation. Therefore this study investigates morphologies, structures, and thermo-chemical properties of as-electrospun and stretched PAN nanofiber bundles by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC).