Dielectric relaxation mechanisms in polyoxymethylene/polyurethane/layered silicates hybrid nanocomposites
| Autor: | P. K. Karahaliou, Stavroula N. Georga, Georgios C. Psarras, Georgia N. Tomara, József Karger-Kocsis, Suchart Siengchin, Christoforos A. Krontiras |
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| Rok vydání: | 2017 |
| Předmět: |
Nanocomposite
Materials science Polymers and Plastics Polyoxymethylene Scanning electron microscope Organic Chemistry General Physics and Astronomy 02 engineering and technology Dielectric Atmospheric temperature range 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound chemistry Transmission electron microscopy Masterbatch Materials Chemistry Composite material 0210 nano-technology Ternary operation |
| Zdroj: | European Polymer Journal. 95:304-313 |
| ISSN: | 0014-3057 |
| Popis: | Polyoxymethylene/Polyurethane/Layered Silicates (POM/PU/LS) ternary hybrid nanocomposites were prepared by two methods: (a) direct melt compounding (DM) and (b) melt compounding using a latex-mediated masterbatch (MB) technique. The morphology of the produced specimens and the quality of the dispersion of LS (synthetic sodium fluorohectorite) were examined via Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Broadband dielectric spectroscopy (BDS) was employed in order to study the dielectric response of the two systems in a wide frequency and temperature range. Rich dielectric spectra are recorded, since dielectric relaxation mechanisms originate from POM matrix, PU latex as well as from interfacial phenomena between electrically heterogeneous components of the nanocomposite. Six different mechanisms contribute to the recorded spectra of the examined nanocomposites which are denoted, in terms of decreasing temperature at constant frequency, as Maxwell-Wagner-Sillars (MWS) effect merged with contribution from the DC conductivity, α-mode of POM, α-mode of PU, γ- and δ-modes of POM and γ-mode of PU. The dynamics of the recorded processes as well as the effect of the preparation technique, on the way these processes are imprinted in the dielectric spectra of the examined systems, are considered and discussed. |
| Databáze: | OpenAIRE |
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