ESTIMATION, USING INFRARED SPECTROSCOPY, OF THE CYCLIZATION OF POLY(ACRYLONITRILE) DURING THE STABILIZATION STAGE OF CARBON FIBRE PRODUCTION

摘要

This paper describes an FTIR method for quantifying the extent of conversion from PAN to oxidized (stabilized) PAN fibre in a series of partially-treated commercial samples. The conversion is quantified in terms of a ''conversion index''. The results are considered in comparison with estimates obtained using WAXD and DSC measurements, and also with respect to changes in tensile strength of the samples. It is concluded that WAXD underestimates the degree of conversion in the initial stages of oxidation, and that DSC overestimates it near the end of the process. In contrast, the FTIR method is capable of giving a good indication of the conversion throughout the entire treatment period. The strength decreases monotonically through the series of samples, and correlates well with values of the conversion index as determined from FTIR. [References: 14]