Orientational Measurements in Polymers Using Infrared Dichroism

4 Orientational Measurements in Polymers Using Infrared Dichroism 

Orientation in polymeric materials is a phenomenon of great practical and theoretical interest. The measurement of orientation provides a basis for the description of both the process whereby the oriented polymer is formed as well as the accompanying modification of its physical properties. 

Among other techniques such as X-ray diffraction, birefringence, NMR spectroscopy, polarized fluorescence, Raman depolarization and sonic techniques the 

When an oriented polymer is investigated with linearly polarized radiation the alworlmnce a of a single group in the polymer chain is proportional to the square of the scalar product of its transition moment vector M and the electric vector E of the incident polarized radiation  

on the other hand, the intensity of an absorption band exclusive of contributions due to the orientation of a highly elongated polymer is required for quantitative analysis, the so-called structural absorbance Ao has to be evaluated from polarization measurements  

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