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Percolation Effect on the Complex Permittivities of Polymer Blends
Hsien-Wen Chao1, Yun-Yu Lai2, Tsun-Hsu Chang1
1Department of Physics, National Tsing Hua University, 101, Section 2, Kuang Fu Road, Hsinchu 300044, Taiwan.
Polymers
|September 28, 2023
Summary
This study measures complex permittivities of polymer blends using field enhancement method (FEM). A percolation effect was observed, significantly increasing dielectric constants and loss tangents with higher solute concentrations.
Area of Science:
- Materials Science
- Dielectric Spectroscopy
- Polymer Physics
Background:
- Understanding the dielectric properties of polymer blends is crucial for their application in various electronic and electrical devices.
- The field enhancement method (FEM) offers a sensitive technique for characterizing the complex permittivity of materials.
- Polymer blends, especially those involving solvent-solute mixtures, can exhibit complex dielectric behaviors influenced by concentration and phase transitions.
Purpose of the Study:
- To measure and analyze the complex permittivities of polymer blends, specifically DC-840, MCL-805, and MCL-Siloxane, using the field enhancement method (FEM).
- To investigate the influence of solute concentration on the dielectric constant and loss tangents of polymer blends.
- To elucidate the observed percolation phenomenon and its correlation with blend viscosity using effective medium theories and dielectric models.
Main Methods:
- Utilized the field enhancement method (FEM) by placing polymer blend samples in a Teflon holder within the FEM cavity.
- Determined complex permittivity by measuring the resonant frequency and quality factor of the FEM cavity coupled with the samples.
- Employed effective medium theories, high-frequency structure simulator (HFSS), generalized dielectric constant, and the Debye model to analyze experimental data.
Main Results:
- The complex permittivities of DC-840, MCL-805, and MCL-Siloxane blends were successfully extracted.
- A significant increase in dielectric constants and loss tangents was observed in DC-840/xylene blends above a critical solute volume fraction, indicating a percolation effect.
- The percolation phenomenon was found to strongly correlate with the viscosity of the polymer blends.
Conclusions:
- The field enhancement method (FEM) is effective for characterizing the dielectric properties of polymer blends.
- Percolation significantly impacts the dielectric behavior of polymer blends, particularly at higher solute concentrations.
- The generalized dielectric constant and Debye model provide valuable frameworks for explaining the observed percolation effects on dielectric properties.
Keywords:
complex permittivitycontour mapping methodenhanced field methodpercolation effectpolymer blendsMore Related Videos
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