Dielectric Properties of Azo Dye-Poly(methyl methacrylate) Mixtures

Du Lei, James Patrick Runt, A. Safari, R. E. Newnham

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66 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)1797-1801
Number of pages5
Issue number8
StatePublished - Aug 1 1987

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry


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