Novel Carbon Fiber Synthesis Process Based on Joule Heating

Carbon fibers possess high stiffness and tensile strength, are lightweight, and have high chemical and thermal resistance. These set of properties make them indispensable in multiple industries such as aerospace, civil engineering, and military. However, carbon fibers are relatively expensive compared to glass or plastic fibers, and carbon fiber composites are expensive then steel, which limits its use in cost-sensitive, high-volume industrial applications such as automobiles, oil and gas, and infrastructure. Current methods for manufacturing carbon fiber rely on high temperature ovens for the stabilization/oxidation and carbonization steps, which tend to be slow and energy intensive. In this Phase 1 SBIR proposal, we plan to further develop a novel process for low-cost manufacturing of carbon fibers, that could reduce energy consumption by >25%. The process depends on the use of Joule heating of polyacrylonitrile/carbon nanotube precursors. The temperature of fiber precursor can be increased to several hundreds of degree Celsius, based on both theoretical calculations according to one-dimensional steady-state heat transfer equation as well as experimental infrared measurements, which shows that the temperature can be high enough to stabilize and carbonize carbon fibers. In Phase 1 of this proposal, we will produce development quantities of carbon fiber by dry-jet wet spun process of PAN/CNT precursor, followed by Joule heating for fiber stabilization and carbonization. We will characterize the carbon fibers with SEM, mechanical tests, DMA, XRD, and FTIR. Process optimization will also be performed in Phase 1 to improve the mechanical properties of the fibers.