Thermal Engineering of Lignin for Low-cost Production of Carbon Fiber

Abstract

Lignin, a sustainable, renewable resource material, is being evaluated for the low cost production of carbon fiber for automotive and other applications. We previously reported the successful production of carbon fiber from a solvent extracted lignin [1] and from other lignins [2]. However, it was found that the lignin fiber, produced by the melt spinning of the solvent extracted lignin, was difficult to stabilize (i.e., render infusible) and thus carbonize. The long stabilization time, due to the fiber’s low Tg, led to the conclusion that thermal engineering of a lignin feedstock could ultimately raise the Tg of the lignin and thereby of the spun fiber. This would permit a higher temperature of stabilization, which would reduce stabilization time as well as overall processing times. The thermally-engineered lignins were evaluated in terms of their rheological properties, melt spinning ability, morphology, stabilization and carbonization properties, and ultimately mechanical properties of the carbon fibers obtained.