Dielectric relaxation of conductive carbon black reinforced ethylene-octene copolymer vulcanizates
Autor: | Nimai C. Nayak, P. Ganga Raju Achary, Ram Narayan Prasad Choudhary, Suchilipsa Das |
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Rok vydání: | 2014 |
Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Relaxation (NMR) Percolation threshold 02 engineering and technology General Chemistry Polymer Carbon black Dielectric 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry Natural rubber visual_art Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Dielectric loss Composite material Nyquist plot 0210 nano-technology |
Zdroj: | Polymer Composites. 37:342-352 |
ISSN: | 0272-8397 |
Popis: | The dielectric relaxation behavior of different conducting carbon black-filled ethylene-octene copolymer (EOC) vulcanizates prepared by melt-mixing method has been studied as a function of frequency (100 Hz–5 MHz) over a wide range of temperatures (25–100°C). The effect of filler loading and frequency on AC conductivity, dielectric permittivity, impedance, and dielectric loss tangent (tanδ) has been studied. The nature of variation of the dielectric permittivity with the filler loadings was explained on the basis of interfacial polarization of the filler in the polymer matrix. The effect of filler loading on the real and complex part of the impedance was explained by the relaxation dynamics of the polymer chains in the vicinity of the fillers. The effect of filler and temperature on dielectric loss tangent, dielectric permittivity, AC conductivity, and Nyquist plot was also reported. The bound rubber (BR) value increases with increase in filler loading suggesting the formation of strong interphase, which is correlated with dielectric loss. Thermal activation energy (Ea) was found to be decreasing with the temperature, which follows the Arrhenius relation: τb = τ0 exp(−Ea/KBT) where τb is the relaxation time for the bulk material. From the plot of lnτb versus inverse of absolute temperature (1/T), the activation energies (Ea) were found to be 0.37 and 0.44eV, respectively. The percolation threshold was observed with 40 phr carbon black loading. POLYM. COMPOS., 37:342–352, 2016. © 2014 Society of Plastics Engineers |
Databáze: | OpenAIRE |
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