Abstract
Flexible active materials for tyre sensors become increasingly more relevant, leading to a growing interest in developing conductive elastomers. The present work aims to identify the most influential factors towards enhanced electrical conductivity of rubber compounds. The electrical conductivity was measured under simulated tyre rolling conditions using an in-house developed measurement setup including a modified Dynamic Mechanical Analyser (DMA).
The influences of various parameters: rubber types and blends, carbon black types and amounts were investigated. Based on a full factorial Design of Experiments, blend ratios of different types of rubbers (Natural Rubber (NR), Butadiene Rubber (BR), Epoxidized NR and functionalized BR) reveal to be statistically insignificant. The carbon black amount was the only significant factor. Various grades of carbon blacks with surface area in the range of 78 and
1400 m2/g showed the same value of conductivity in the conduction region. High surface area carbon black only differs for the relatively low percolation threshold, which implies an easier mixing process and better dispersion. To further understand the influence of carbon blacks, the Sigmoidal-Boltzmann model was applied to predict the percolation threshold of NR/BR composites by the specific surface area of the carbon blacks. The sigmoidal correlation can also be obtained by plotting the electrical conductivity and the Payne effect as an indication of
filler-filler interaction. This gives a new possible approach towards determining the onset point of the percolation region of conductive compounds.
The influences of various parameters: rubber types and blends, carbon black types and amounts were investigated. Based on a full factorial Design of Experiments, blend ratios of different types of rubbers (Natural Rubber (NR), Butadiene Rubber (BR), Epoxidized NR and functionalized BR) reveal to be statistically insignificant. The carbon black amount was the only significant factor. Various grades of carbon blacks with surface area in the range of 78 and
1400 m2/g showed the same value of conductivity in the conduction region. High surface area carbon black only differs for the relatively low percolation threshold, which implies an easier mixing process and better dispersion. To further understand the influence of carbon blacks, the Sigmoidal-Boltzmann model was applied to predict the percolation threshold of NR/BR composites by the specific surface area of the carbon blacks. The sigmoidal correlation can also be obtained by plotting the electrical conductivity and the Payne effect as an indication of
filler-filler interaction. This gives a new possible approach towards determining the onset point of the percolation region of conductive compounds.
| Original language | English |
|---|---|
| Number of pages | 15 |
| Publication status | Published - 28 Jun 2022 |
| Event | German Rubber Conference and International Rubber Conference, DKT IRC 2021 - Nuremberg, Germany Duration: 27 Jun 2022 → 30 Jun 2022 |
Conference
| Conference | German Rubber Conference and International Rubber Conference, DKT IRC 2021 |
|---|---|
| Abbreviated title | DKT IRC |
| Country/Territory | Germany |
| City | Nuremberg |
| Period | 27/06/22 → 30/06/22 |
Keywords
- Elastomeric composite
- carbon black
- electrical conductivity
- percolation threshold