Calculations of infrared difference spectra of polymer blends and pure components have been made based on models with no intermolecular bonding interactions. The results demonstrate that residual peaks can arise from optical phenomena based solely on the effects of differences in the real part of the refractive indices of the pure components. Accordingly, chemical interpretations, such as intermolecular bonding interactions, of residual difference peaks must be made with caution in blends where the real refractive indices of the components differ by several percent or more in absorption-free energy regions.
For example, see SternF. in Solid State Physics, Advances in Research and Applications, SeitzF.TurnbullD., Eds. (Academic Press, New York, 1963), Vol. 15, pp. 299–408.
5.
AllaraD. L.BacaA.PrydeC. A., Macromolecules11, 1215 (1978).
6.
HeavensO. S., Optical Properties of Thin Solid Films (Dover, New York, 1965), Chap. 4. For a presentation of the fundamental principles see BornM.WolfE., Principles of Optics, 5th ed. (Pergamon Press, New York, 1975).
