STRUCTURE-PROPERTY RELATIONSHIPS IN CARBON-FIBERS

Raman spectroscopic studies on the deformation of carbon fibres showed that the rates of Raman shift per unit strain for both PAN and mesophase pitch based fibres, increase linearly with Young's modulus with different slopes. Both types of fibre have been examined using electron microscopy and Raman spectroscopy. The results demonstrate that there is a profound skin-core difference in PAN based fibres. The skin of the PAN based fibre has a higher modulus, which gives rise to a larger rate of Raman shift.