A new approach to thermal stabilisation of PAN fibres

Differential scanning calorimetry of PAN fibres shows a prominent exothermic peak at about 270°C. An additional exothermic peak at about 350°C has been observed in the present study. Following various characterization techniques such as density, diameter, mechanical properties, elemental analysis, etc., it has been proposed that this peak is associated with certain intermolecular crosslinking reactions as well as with the aromatization of the structure during thermal stabilisation of PAN fibres. The study concludes that the PAN fibres oxidised to 350°C and above, compared to only 270°C, followed conventionally so far as reported in the open literature, results in much better stabilised structure. Carbon fibres prepared from such samples show significant improvement in mechanical properties.