Currently, three precursor materials are used for commercial
production of carbon fibers: polyacrylonitrile (PAN), pitch
and rayon [1]. Of these, PAN is used almost exclusively to
produce high strength carbon fibers. The process involves
generation of certain toxic by-products such as hydrogen cyanide
(HCN). This environmental problem can potentially be
overcome by the use of naturally occurring biomass, including
lignin. Unfortunately, most current grades of lignin are
intractable, so its chemical modification is needed for further
processing.