Broadband dielectric spectroscopy polymers

Urman, K., Madbouly, S., and Otaigbe, J.U. (2007) Unusual accelerated molecular relaxations of a tin fluorophosphate glass/polyamide 6 hybrid studied by broadband dielectric spectroscopy. Polymer, 48, 1659-1666. 

Arbe A, Colmenero J, Richter D (2002) In Kremer F, Schonhals A (eds) Polymer dynamics by dielectric spectroscopy and neutron scattering - a comparison in broadband dielectric spectroscopy... 

Broadband Dielectric Spectroscopy provides a direct experimental access to the molecular relaxations of polymers over a broad frequency and temperature range. It is also especially suitable for the investigation of thin polymer films, because it does not suffer sensitivity loses with decreasing sample amount. This technique does require a special sample preparation for thin films, because of the need to have metal electrodes and good electrical contacts at both interfaces. Spin-coating, one of the most commonly employed methods for the preparation of... 

This chapter concentrates on the results of DS study of the structure, dynamics, and macroscopic behavior of complex materials. First, we present an introduction to the basic concepts of dielectric polarization in static and time-dependent fields, before the dielectric spectroscopy technique itself is reviewed for both frequency and time domains. This part has three sections, namely, broadband dielectric spectroscopy, time-domain dielectric spectroscopy, and a section where different aspects of data treatment and fitting routines are discussed in detail. Then, some examples of dielectric responses observed in various disordered materials are presented. Finally, we will consider the experimental evidence of non-Debye dielectric responses in several complex disordered systems such as microemulsions, porous glasses, porous silicon, H-bonding liquids, aqueous solutions of polymers, and composite materials. 

The characterization of the physical and chemical changes that occur in montmorillonite/PDMS nanocomposite elastomers as they are thermally aged is reported. Broadband Dielectric Spectroscopy (BDS) was used to track changes in the physical interaction between the polymer and clay associated with increases in non-oxidative thermal stability (as determined by TGA). The evolution of volatile siloxane species from the elastomers was characterized with Thermal Volatilization Analysis (TVA). Results suggest that the improved thermal stability and the increases in polymer/clay association are a result of significant re-structuring of the polymer network. 

In relation to the questions addressed in the introduction, the following answers are given, based on experimental results obtained for three polymer systems investigated in thin layers using broadband dielectric spectroscopy, capacitive scanning dilatometry, and calorimetry ... 

Broadband dielectric spectroscopy is a powerful tool to investigate polymeric systems (see [38]) including polymer-based nanocomposites with different nanofillers like silica [39], polyhedral oligomeric silsesquioxane (POSS) [40-42], and layered silica systems [43-47] just to mention a few. Recently, this method was applied to study the behavior of nanocomposites based on polyethylene and Al-Mg LDH (AlMg-LDH) [48]. The properties of nanocomposites are related to the small size of the filler and its dispersion on the nanometer scale. Besides this, the interfacial area between the nanoparticles and the matrix is crucial for the properties of nanocomposites. Because of the high surface-to-volume ratio of the nanoparticles, the volume fraction of the interfacial area is high. For polyolefin systems, this interfacial area might be accessible by dielectric spectroscopy because polyolefins are nonpolar and, therefore, the polymeric matrix is dielectrically invisible [48]. 

Schonhals, A. 2002. Molecular dynamics in polymer model systems. In Broadband Dielectric Spectroscopy, ed. F. Kremer, A. Schonhals, p. 225. Berlin, Germany Springer. 

Broadband Dielectric Spectroscopy to Study the Molecular Dynamics of Polymers Having Different Molecular Architectures... 

Broadband dielectric spectroscopy (BDS) is a versatile experimental tool to study the dynamics of polymeric systems. In its modem form it covers the extraordinary frequency range from 10 Hz to 10 Hz with the option to extend both limits to lower and higher values, respectively. This enables one to analyse the molecular d3mamics on a large time scale especially if the temperature of the sample is varied as well. In the present review article examples will be discussed for polymers of widely varying molecular architectures (linear and cyclic chains, star-branched systems, and liquid crystalline polymers). 

Measurements of dielectric constant and loss in polymeric solids and melts over a wide frequency range were described in detail elsewhere (Porter and Boyd 1972). An updated and detailed account of these topics may be found in Chap. 12, Broadband Dielectric Spectroscopy on Polymer Blends of this handbook (Andreas Schonhals 2014). 

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