The microstructure of PAN-base carbon fibres

The microstructure of polyacrylonitrile-base (PAN-base) type I and type II carbon fibres has been studied by X-ray small-angle and wide-angle scattering. Recent work in this field is critically reviewed and it is shown that the structural model proposed by Johnson & Tyson for these types of fibre is inadequate. The microstructure of PAN-base carbon fibres is essentially the same as that of rayon-base carbon fibres. Differences appear only in the volume fraction occupied by the microvoids.