ABSTRACT
Carbon fibers have now been available for some 35 years and in that time, many significant improvements have been made. The replacement of cellulose based precursors with PAN precursors provided carbon fibers with good strength and improved the moduli, followed later by the intermediate modulus PAN based range, whilst the pitch based fibers were available with very high moduli and were truly graphitic. In the 1980s, the US Government made it mandatory for military applications to use PAN precursor made in the USA, which heralded an increase in production of PAN precursor in the US.
