Effect of the matrix crystallinity on the percolation threshold and dielectric behavior in percolative composites

Abstract

Through the use of polyethylenes with different crystallinities as matrices, the effects of the matrix crystallinity on the percolation threshold and dielectric behavior of percolative composites have been investigated. The results suggest that the percolation threshold is negatively related to the matrix crystallinity, whereas the enhancement of the dielectric constant is positively related to the matrix crystallinity. A two-dimensional diagram is proposed to illustrate such relationships. In addition, it has been found that the insulator-conductor transition is much flatter in low-crystallinity-matrix-based composites, and this may be favorable for preparing threshold composites with a high dielectric constant and a low loss tangent.

Polyamide 11/Poly(vinylidene fluoride)/Vinyl Acetate-Maleic Anhydride Copolymer as Novel Blends Flexible Materials for Capacitors

“…In the review by Scheinbeim et al [18,19], the authors reported the odd-numbered Nylons such as polyamide (PA11) exhibiting fine piezoelectric behavior by appropriate electro processing, especially when the temperature is raised above the glass transition temperature of the nylons [20,21]. However, most polymer blends are immiscible and form a multiphase structure because of the high molecular weight and unfavorable interactions between the component polymers.…”

Expression of the novel Golgi protein GoPro49 is developmentally regulated during mesenchymal differentiation

“…The glass transition of the matrix polymer in polymer nanocomposites is affected by the presence of and interactions with the filler and its investigation provides significant information on polymer‐filler interactions and on morphology 10. The same is true also for the crystallization and melting transitions in semicrystalline polymer matrices 11, 12. The influence on the thermal transitions of the semicrystalline polypropylene matrix has been investigated by differential scanning calorimetry (DSC) in PP/PPy composites and PP/PPy/MMT nanocomposites in a previous work 13…”

Shape memory composites based on a thermoplastic elastomer polyethylene with carbon nanostructures stimulated by heat and solar radiation having piezoresistive behavior

“…The electrical percolation thresholds in our composites are high as compared with other polymer composites, meaning a poor dispersion of carbon nanoparticles able to reduce the effective particle aspect ratio . Moreover, in copolymers having low crystallinities such as TEPE, the percolation threshold is even higher due to the inverse relationship between the concentration threshold and the matrix crystallinity that is found in similar systems . Hereafter, composites with 8 and 14 wt% of filler were tested regarding their SME as they allowed the analysis of both the percolation transition and type of filler.…”

“…49 Moreover, in copolymers having low crystallinities such as TEPE, the percolation threshold is even higher due to the inverse relationship between the concentration threshold and the matrix crystallinity that is found in similar systems. 50 Hereafter, composites with 8 and 14 wt% of filler were tested regarding their SME as they allowed the analysis of both the percolation transition and type of filler.…”