Optical properties and constants

An in-sample compartment reflection accessory was also used in determining the optical constants (n, real refractive index, and k, absorption coefficient) for polymer films PET [318], polycarbonate [319], and PAN [320]. Many polymers are used as lens or window materials, because of their transparency, in the far-IR (10 00 cm ) as well as in the visible. The optical constants of polymers such as TPX (poly-4-methylpent-l-ene) [321] and PET [322] have 

Vibrational spectroscopy techniques will continue to be key tools in polymer characterisation and structure elucidation. The general applicability of FTIR techniques to all morphological and processed forms has been enhanced by the arrival of the simply operated FT-Raman systems, which supplement a wide range of established and complementary uses of Raman spectroscopy. 

Unfortunately, space constraints have prevented detailed discussions of an array of techniques that further enhance the utility of vibrational spectroscopy in polymer studies. These include surface enhanced Raman spectroscopy (SERS) and waveguide Raman spectroscopy for the study of surfaces, and for quality-control and process studies. The latter technique, particularly in conjunction with multivariate analysis software routines, is rapidly becoming important in monitoring and controlling modern production facilities. However, discussion of these and other areas can be found in many of the references cited in this chapter. 

Herzberg (1945). Infrared and Raman Spectra of Polyatomic Molecules, Van Nostrand, New York. 

Wilson, J. C. Deems and P. C. Cross (1955). Molecular Vibrations, McGraw-Hill, New York. 

---