Secondary relaxations in polycarbonate of bisphenol

Both for the phenylene-ring rotation and for the carbonate-group rearrangement comparison of the actual activation paths of the relaxation with possible 

The average activation energies obtained by the simulation, i.e., 10.4 kcal/mole for the ring flip and 10.1 kcal/mole for the carbonate-group rearrangement, compared very well to the NMR results of Roy et al. (1986) and Walton et al. (1990) ranging between 9.1 and 12.0 kcal/mole. 

Traditionally, wide-ranging relaxation-time distributions P i) relative to population-average times r have been described by stretched exponentials of the Kohlrausch-Williams-Watts type given by (see Chapter 1) 

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