Infrared Spectroscopy of Polyethylene Terephthalate Fibers: Uses and Limitations

Abstract
The potential of Fourier-Transform Infrared (FTIR) spectroscopy for characterizing polyethylene terephthalate (PET) fibers is examined both from a practical and a theoretical view point. Problems associated with sample preparation, spectral data analysis, and refraction and reflection at the fiber surfaces are discussed. The FTIR technique is used to characterize a range of partially-oriented PET fibers with differing fabrication histories and to determine the level of amorphous orientation in drawn PET fibers.