Dynamic Electrical and Electromechanical Properties of Carbon-Black Loaded Rubber

Abstract

1. Low-frequency resistance can be dominated by contacts. It was found that silver paint contacts were roughly equivalent to metal contacts bonded during vulcanization. 2. Three electrical regimes are clearly evident, determined by loading: dielectric, percolation, and conducting. 3. Resistance and dielectric constant dispersion for loading above 30 phr agree with Kawamoto's model. 4. Each carbon-black loading results in a distinctive dispersion signature. 5. Dynamic conductivity can be used to delineate persistent and transient carbon-black-structure changes versus composition, DSA, frequency, and potentially other parameters (temperature, stress waveform, etc.). 6. The remaining conductive network during stress is represented by gmin; Δg is determined by network fracture and reformation; gmin−gα is proportional to the amount of remaining transient structure; g0−gα is proportional to the total transient structure; normalized conductivity Z is the remaining-to-total transient-structure ratio. 7. The Δgm=0.525(g0−gα) relation indicates that maximum reformation occurs when approximately half the transient structure is broken down and confirms the correlation between conductivity parameters and transient carbon-black structure.

Temperature and time dependence of conductive network formation: Dynamic percolation and percolation time

“…The dispersion state of conductive particles in a host polymer affects the final electrical properties [1][2][3][4][5][6][7][8][9][10][11][12][13]. To understand the conductive network formation, percolation theory has been used to describe the relationship between the electrical conductivity and the filler content [14,15].…”

Natural rubber/ethylene propylene diene blends for high insulation iron crossarms

“…Although carbon black dominates the conductive electrical properties of filled rubber,14 the primary purpose of using carbon black in this research is to reinforce the rubber blends. Inclusion of rigid filler particles in the soft matrix (NR) contributes additional filler–rubber interactions resulting in more crosslinking in the flexible network.…”

Studies on Physicomechanical and Electrical Properties of SBR - Carbon Black Composites

“…Figure 1(a) also shows the influence of frequencies on the dielectric constant of the composites. This means that at lower frequencies of from 1 to 500 kHz, a steep increase in dielectric properties can be noticed compared to higher frequency ranges (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). The increase in dielectric behavior at a higher dosage of carbon black loading is due to an increase in filler-filler interaction.…”

“…Electrical and electromechanical measurements for rubber filled with carbon black in the 0-70 phr range were reported by Burton et al [10]. Yacubowicz and Narkis [11] reported the dielectric behavior of carbon black-filled polymer composites.…”