Dielectric Relaxational Behavior of Poly diitaconate s

Polymers derived from itaconic acid show several relaxations below room temperature [245], When these polymers contain cyclohexyl groups in the side chain like 

This is a typical relaxation for this kind of polymers [246,247] and it has been attributed to the chair-to-chair conformational transition of the cyclohexyl ring like in the cases of poly(cycloheyl methacrylate)s. 

The dynamic loss modulus for PDCHI is shown in Fig. 2.81 where two relaxation processes can be observed at —75°C and — 18°C at 1Hz. which are labelled as y and fi. 

From an Arrhenius type plot like that of Fig. 2.82 the activation energies for these processes are obtained an the values are 14.6 and 57.0 kcal mol-1. these results give some idea about the differences in sizes of groups involved in the relaxation. 

To obtain information about both relaxations, the Eyring equation, from the theory of absolute reaction rates, for the dependence of the frequency of an absorption peak on temperature has been used  

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