The dielectric properties of 4-[ethyl(2-hydroxyethyl) amino]-4ʹ-nitroazobenzene-poly (methyl methacrylate) mixtures have been investigated in the temperature range from -20 to 150 °C and the frequency range from 0.1 to 100 kHz. It is found that the observed permittivities can be interpreted satisfactorily in terms of heterogeneous mixture models on the basis of a simple interfacial polarization mechanism. The empirical equation of Havriliak and Negami can be fitted to the a relaxation data of the mixtures and the results are in agreement with inferences from normalized loss factor curves. Dielectric and DSC data reveal that the azo dye has a plasticizing effect on PMMA. The relaxation results also show that 20% dye is a critical concentration above which the β relaxation disappears and the relaxation behavior of the composites becomes independent of the dye content.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry