Poly methacrylate s Containing Heterocyclic Side Groups

3 Poly(methacrylate)s Containing Heterocyclic Side Groups 

Although molecular mobility is severely restricted below the glass transition temperature, the dynamic glass transition temperature (main transition or, conventionally -relaxation) in polymers as it have been described above, is usually accompanied by subglass secondary relaxations labeled as p, y, S, relaxations. The glass transition at low temperatures is assumed to be caused by the cooperative motion of many particles, while the secondary relaxations have a more localized molecular 

On the other hand the effect of small modifications of the side chain affect the dielectric response what have been reported in other polymer systems containing cyclohexyl groups [27], In this case the substitution of carbon atoms by oxygen in the cycloheyl ring affect the relaxational behavior of the resulting polymer. 

The dielectric and mechanical relaxations on poly(l,3-dioxan-5yl-methacrylate) (PDMA) [104], show that this polymer present a variety of absorptions due to the versatility of its structural moiety [105]. Recently this behavior have been studied by molecular dynamic simulation using different methods and force fields [106-109], These polymers are analyzed from molecular simulation using different ways but 

This process is partially overlapped with the next process, the j3 relaxation. To analyze the loss permittivity in the subglass zone in a more detailed way, the fitting of the loss factor permittivity by means of usual equations is a good way to get confidence about this process [69], Following procedures described above Fig. 2.42 represent the lost factor data and deconvolution in two Fuoss Kirwood [69] as function of temperature at 10.3 Hz for P4THPMA. In Fig. 2.43 show the y and relaxations that result from the application of the multiple nonlinear regression analysis to the loss factor against temperature. The sum of the two calculated relaxations is very close to that in the experimental curve. 

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