ABSTRACT
Since the early work of Edison, many types of precursors have been used to produce carbon fibers, of which polyacrylonitrile (PAN) has proved to be the most popular.
The ideal requirements for a precursor are that it should be easily converted to carbon fiber, give a high carbon yield and allow to be processed economically. The attraction of PAN is that the polymer has a continuous carbon backbone and the nitrile groups are ideally placed for cyclization reaction to occur, producing a ladder polymer, believed to be the first stage towards the carbon structure of the final fiber.
