Polyacrylonitrile/acrylamide-based carbon fibers prepared using a solvent-free coagulation process: fiber properties and its structure evolution during stabilization and carbonization

Abstract

Polyacrylonitrile (PAN)/acrylamide (AM) fibers were fabricated via dry-jet wet spinning process using a solvent-free coagulation bath. The effects of AM loading as comonomer on the mechanical and thermal properties of PAN-based carbon fiber have been studied. The thermal stability and mechanical stability of the fibers were characterized using differential scanning calorimetry (DSC) and tensile testing. Fibers fabricated from PAN with 5 wt% AM had the highest Young Modulus at 5.54 GPa. It also showed better exothermic trend process with broader exothermic peak and lower initiation stabilization temperature compared with homopolymer PAN. The elemental composition and chemical structure evolution of the fibers during the heat treatment processes were evaluated by elemental analyzer and Fourier Transform Infrared Spectroscopy. Crystal structure evolution of the fibers during the heat treatment process was elucidated by X-ray diffraction (XRD) analysis. The elemental analyzer, XRD and FTIR results revealed that pyrolysis process used had successfully transformed PAN/AM fibers produced from solvent free coagulation bath into carbon fibers that were comparable with the conventional coagulation bath.