Effects of crosslinking reaction and extension strain on the electrical properties of silicone rubber/carbon nanofiller composites

Abstract

Stretchable conductive silicone rubber (SR) composites are important in wearable electronic devices and the crosslinking of SR composites is necessary for their applications. But the effect of the crosslinking reaction on the electrical conductivity of SR composites is rarely reported. In this article, the effect of crosslinking reaction on the electrical conductivity of SR composites filled with conductive carbon black, carbon nanotubes, and graphene are studied. The crosslink density of SR composites increases with increasing curing time, but the electrical conductivity decreases sharply at the early stage of crosslinking, especially for SR/conductive carbon black composite, which is ascribed to the reaggregation of conductive nanofillers in SR during the crosslinking process. The elastic modulus of the three SR composites gradually increases while the elongation at break decreases with increasing curing time, and the SR/carbon black composite shows ultra‐high elongation at break (1578%). In addition, SR/graphene composite is more sensitive to the extension strain than SR/carbon black and SR/carbon nanotubes composites, and its gauge factor is 414 at the strain ranges of 3–25%. This research work brings a new method to optimize the crosslinking structure of conductive SR composites.

Effects of Electrode Materials and Compositions on the Resistance Behavior of Dielectric Elastomer Transducers

“…When the maximal stretch is reached and the sample is released, the behavior is mirrored: the resistance increases first to a second maximum and then drops to its initial value when the sample is relaxed. This phenomenon could be seen for both displacement- and pressure-controlled testing conditions [ 7 , 8 , 24 , 27 , 33 , 37 ]. To understand and be able to control this behavior, this paper investigates the DE electrode resistance in relation to its material composition.…”

“…Understanding and knowing the resistance behavior could also allow new applications, such as monitoring electrode degradation by means of the change in resistance in long-term applications. Looking at earlier research, where the electrical resistance of filled polymeric conductive materials is investigated during elongation, the electrical resistance behaves in significantly different ways for different compositions: While many compositions exhibit a monotonically increasing electrical resistance with increasing elongation [ 27 , 33 , 34 , 35 , 36 ], the electrical resistance of other electrode materials shows a different (i.e., bimodal) behavior. An example of such behavior is shown in Figure 1 .…”

Mechanical properties, thermal stability, and thermal degradation kinetics of silicone rubber/ethylene‐vinyl acetate copolymer/magnesium sulfate whisker composites compatibilized by ethylene‐acrylic acid copolymer

“…It is widely used in high‐voltage insulation because of its lightweight, superior hydrophobicity, and wide temperature range due to its unique chemical structure. But its relatively poor mechanical properties reduce its application in many fields 1–3 . Ethylene‐vinyl acetate copolymer (EVA) is prevailing in many applications, including packaging films, cable insulation, adhesives, coatings, and barrier sheets.…”

“…But its relatively poor mechanical properties reduce its application in many fields. [1][2][3] Ethylene-vinyl acetate copolymer (EVA) is prevailing in many applications, including packaging films, cable insulation, adhesives, coatings, and barrier sheets. However, its extreme temperature properties are inferior to those of silicone rubber.…”

Influence of dispersing aids on nano alumina/micro aluminum tri hydrate filled silicone rubber composites for outdoor high voltage insulators

“…With polymeric materials emerging as a favorable choice for outdoor insulators, the incorporation of nanoparticles in the base matrix has yielded promising results. [1][2][3][4][5][6] Silicone rubber due to its outstanding properties of hydrophobicity transfer and recovery is a proven material for outdoor insulator applications. To compensate for the inherently poor thermal conductivity of silicone rubber (0.2 W m À1 K À1 ), 7 which becomes detrimental in case of tracking and erosion behavior, it is often filled with copious amounts of flame retardants such as aluminum tri hydrate (ATH) in varying micron sizes.…”