Time dependence of orientational

Dynamic birefringence techniques have been developed by Stein et al. (66), Read (54), Yamada and Hayashi (85) and Hopkins (25). By this technique the stress, strain and birefringence are measured simultaneously while the applied strain varies. By making such measurements as a function of frequency and temperature one can in principle separate the time dependencies of orientation of molecular response in a multiphase system as well as correlate the optical behavior with the mechanical spectrum. This technique can be correlated for example with the dynamic X-ray technique allowing separation of the amorphous and crystalline behavior. 

Figure 12.22 Time dependence of orientation function change of PCL annealed on the oriented PE substrate at 59 °C. Yan et al. [166]. Reproduced with permission of American Chemical Society.

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