Carbon fibers are derived from precursors, with polyacrylonitrile (PAN) fibers being the predominant precursors used today. All commercial PAN fibers are presently wet or dry spun with expensive, environmentally harmful solvents. Over the past several decades efforts have been made to generate PAN fibers using the melt-spinning process. Melt-spun fibers were generated successfully from PAN copolymers plasticized with water. However, the fibers were found to have too many voids and other flaws to be used as carbon fiber precursors.Our current work has centered on reducing the voids and flaws of melt-spun fibers with the goal of making them suitable for precursor applications. Fiber spinning was carried out using PAN copolymers containing 93 mol-% or more AN mixed with about 20 wt% of water. Differing from all previous work reported in the literature, we pressurized the fiber formation zone with nitrogen and increased the gas pressure to a level equal to or above the saturated steam pressure at the extrusion temperature as shown in the figure. This was done to eliminate or minimize the formation of bubbles or voids when the fibers solidify. It was found that the PAN fibers generated in such conditions have less voids, more uniform internal structure, and great potential to be used as carbon fiber precursors. The mechanical properties of the fibers were reported and compared with that of existing PAN fibers. 

Melt spinning of polyacrylonitrile fibers as carbon fiber precursors

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.