Evaluation of crystallinity in carbon fiber-reinforced poly(ether ether ketone) by using infrared low frequency Raman spectroscopy

The degree of crystallinity of poly(ether ether ketone) (PEEK) in carbon fiber reinforced composites were evaluated by using infrared low frequency Raman spectroscopy. Reference PEEK samples with varying crystallinity which are evaluated using wide-angle X-ray diffraction (WAXRD) were prepared. These samples were used to create a calibration curve for crystallinity using low frequency Raman spectroscopy. The WAXRD and low frequency Raman methods directly correlated. Carbon fiber reinforced PEEK samples with different cooling rates were prepared and the crystallinity was determined by using low frequency Raman spectrosopy. The crystallinity of the air-cooled sample, water-cooled sample, contact with metal plate and water-cooled sample are 36%, 33%, and 17%, respectively.