Development of a Program for Analyzing Dielectric Relaxation and Its Application to Polymers: Nitrile Butadiene Rubber

Abstract

To characterize the dielectric relaxation embedded in polymers, we developed a program algorithm that analyzes the relaxation processes from dielectric permittivity versus frequency data based on governing functions such as the Havriliak-Negami function including the conductivity contribution. With the help of the developed simulation program, we have identified three processes: an α process due to rotational and segmental motions of the C-C bond, an α' process attributed to the fluctuation of the end-to-end dipole vector of the polymer chain, and the conduction contribution observed at high temperatures and low frequencies. The activation energy and glass transition temperature for the two main relaxations were independently determined from both the imaginary permittivity versus frequency and temperature by assuming Arrhenius dependence and the Vogel-Fulcher-Tamman law. The results obtained by the two methods for α and α' relaxations were compared with each other and with that obtained by differential scanning calorimetry.

Polarization of ionic liquid and polymer and its implications for polymerized ionic liquids: An overview towards a new theory and simulation

“…The study of the polymer solution in Reference 161 showed that water clustering is likely to occur at high polymer concentrations, substantially affecting the DR processes. A recent study in Reference 163 developed a novel program algorithm that supports the analyzing of DR based on data from the DRS method. Relying on the Havriliak–Negami function, the algorithm identified DR modes or processes due to the segmental motions, end‐to‐end polymer chain fluctuations, and conduction contribution.…”

Characterization of Dielectric Relaxation Process by Impedance Spectroscopy for Polymers: Nitrile Butadiene Rubber and Ethylene Propylene Diene Monomer

“…e present work was performed for NBR specimens produced from both different batches and compositions in [23]. Furthermore, this research is extended to lower frequencies reaching 0.01 Hz.…”

“…is work decomposes the superimposed dielectric spectrum and assigns the peaks of the relaxation processes in the dielectric spectrum, resulting in the characterization of several relaxation processes with a developed dispersion analysis program [23]. e upgraded algorithm is used to analyze the relaxation processes by selectively satisfying either real or imaginary dielectric data based on three governing functions-the Cole and Cole [24], Davidson and Cole [25], and HN [26] functions-together with the conduction contribution.…”

“…e upgraded program is applied to characterize the entire relaxation processes that exist in the two polymers-NBR and EPDM-under study. As the extension of dielectric spectroscopy research on NBR was investigated recently [23], research on EFDM has been completed.…”