Carbon nanofibers prepared by a novel co-extrusion and melt-spinning of phenol formaldehyde-based core/sheath polymer blends
(1870-1876) Journal of Materials Science 46 #6 (2011)|
Kuo-Kuang Cheng, Hsu and Kao, Taiwan used solvent-free core/sheath melt-spinning of polypropylene/(phenol formaldehyde–polyethylene) [PP/(PF–PE)] to prepare the carbon nanofiber.  This method consists of co-extrusion of PP (core) and a polymer blend of PF and PE (sheath), followed by melt-spinning, to form the core/sheath fiber, stabilization of core/sheath fiber to form the carbon fiber precursor, and carbonization of carbon fiber precursor to form the final CNF.  The result is a long and winding carbon nanofiber with diameter 100–600 nm and length greater than 80 μm in oriented bundles which curl up to become rolls of wavy long fibers with clean and smooth surface.  The fibers consist of graphitic particles embedded homogeneously in an amorphous carbon matrix. (RDC 2/22/2011)