The effect of pressure deformation on dielectric and conducting properties of silicone rubber/polypyrrole composites in the percolation threshold region

Abstract

The changes in the frequency dependences of the AC conductivity and complex permittivity during the pressure deformation of silicone rubber/polypyrrole composites have been examined. The experiments revealed that the pressure loading of the composite with particle concentration in the vicinity of the upper part of the percolation region causes disconnection of particle contacts and the transition of the semiconducting particle chain structure to a non-conducting composite structure corresponding to mutually insulated particles below the percolation threshold. A close relation between the frequency dependences of the conductivity and permittivity of the composites at various pressure loadings has been confirmed.

Preparation and Characterization of Extruded PLA Films Coated with Polyaniline or Polypyrrole by In Situ Chemical Polymerization

“…Similarly, for the PLA−PANi film, this was attributed to the high compaction of the polypyrrole particles and their homogeneous distribution (Figure 2c), which facilitates proper charge percolation. 36,37 After the first hour of polymerization, the electrical conductivity of the PLA−PPy films gradually decreased (Figure 5b). This could be related to phase separation present in the composite film due to the formation of polypyrrole agglomerates on the surface of the PLA film.…”

Evaluation of Strain Sensors Based on Poly(acrylonitrile-co-butadiene) and Polypyrrole Synthesized by the Diffusion Method

“…17 Silicone rubber/PPy composites were prepared using PPy powder mixed with polymer matrix components by cast molding between two parallel plates. 18 During the in situ polymerization method, mixing is carried out before polymerization, which allows for a number of changes in the process of incorporating the monomer into the matrix. Some studies report aniline polymerization in ethylene vinyl acetate solution 19 and solution polymerization of pyrrole in nitrile rubber (NBR) using simultaneous mechanical mixing in a two-roll mill.…”

“…The mechanical blending of a polymer solution with toluene as a solvent has been used to evaluate various elastomer/PPy blends . Silicone rubber/PPy composites were prepared using PPy powder mixed with polymer matrix components by cast molding between two parallel plates …”

“… 17 Silicone rubber/PPy composites were prepared using PPy powder mixed with polymer matrix components by cast molding between two parallel plates. 18 …”

Electrical conductivity of epoxy/silicone/carbon black composites: Effect of composite microstructure

“…Since high loading of conducting fillers into the composites is a limiting circumstance for development of commercially applicable materials, a new generation of CPCs with lower filler concentration and higher total conductivity has been developed . Additional advantages of such CPCs are optimization of processing characteristics, cost, and adverse environmental impact reduction .…”