Activation Energy of Secondary Relaxation in Polymers

The dielectric measurement was carried out using a TRS-IOC dielectric loss measuring apparatus (Japan Ando Electric). The heating rate was 2°C min. The effective diameter of the electrode used was 3.8 cm, and a copper foil with a thickness of 22 gm was attached to the specimen in order to maintain close contact between the specimen and the surface of the electrode. 

6 Master Curve of Polymers Using Djmamic Mechanical Spectra 

Measure the dynamic mechanical storage E as a function of temperature at different frequencies. 

Exact matching of the shapes of adjacent curves is necessary, since is one criterion for the applicability of reduced variables. 

LogQj for each temperature (T-Tg) can be calculated by using the experimental curves. 

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The activation energy of secondary relaxation in polymers can be measured by means of dynamic mechanical or dielectric relaxation spectroscopy. Dynamic mechanical or dielectric relaxation spectra of polymers can be obtained as a function of temperature at different frequencies. As an example, the dielectric relaxation behavior of the secondary relaxation in some AB cross-linked polymers is shown in Figure 4.63. 

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