Dielectric Relaxation Behavior of Exfoliated Graphite Nanoplatelet-Filled EPDM Vulcanizates
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- 作者：Bikash Kumar Dash ; P. Ganga Raju Achary ; Nimai C. Nayak…
- 关键词：EPDM ; xGnP ; dielectric ; nyquist plot
- 刊名：Journal of Electronic Materials
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：46
- 期：1
- 页码：563-572
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Optical and Electronic Materials; Characterization and Evaluation of Materials; Electronics and Microelectronics, Instrumentation; Solid State Physics;
- 出版者：Springer US
- ISSN：1543-186X
- 卷排序：46
文摘
The present study investigates the dielectric relaxation and mechanical behavior of exfoliated graphite nanoplatelet (XgnP)-filled ethylene-propylene-diene terpolymer (EPDM) vulcanizates with variation in frequency, temperature and xGnP loading. The samples were prepared by a solution–cast method using toluene as the solvent followed by compression molding. The enhanced permittivity and ac conductivity which sharply changes above 20 wt.% of xGnP loading shows the conducting behavior of the composites. The real parts of the impedance for the vulcanizates were continuously decreased up to 40 wt.% whereas the complex part shows an increasing tendency at the same loading expressing the increase in the conductivity of the vulcanizates. The percolation threshold of the xGnP-loaded EPDM vulcanizates was at 25 wt.% of xGnP loading. A more prominent effect of temperature on dielectric loss tangent is observed at 85°C, and 100°C. The ac conductivity increases with the rise in temperature. The Nyquist plots of xGnP-reinforced EPDM show the small intercepts on the Z′ axis at 85°C, and 100°C for the 40 wt.% loading. The experimental complex impedance plots were in good agreement with the model-fitted plots. The tensile strength of 15 wt.% xGnP-filled vulcanizate increases up to 12 times more than the unfilled EPDM whereas the elongation at break (%) increases up to 700% at the same loading of xGnP. Young’s modulus has been doubled and quadrupled for the vulcanizates with 20 and 40 wt.% of xGnPs, respectively, compared to the pure EPDM samples. The results indicate that the xGnP–EPDM conductive composite can find applications in the area of antistatic material, electrostatic discharge gaskets, etc.