The effect of compressive stress on the electrically resistivity of poly(vinylidene fluoride)/polypyrrole blends

Development of Poly (butylene adipate-co-terephthalate) Filled with Montmorillonite-Polypyrrole for Pressure Sensor Applications

“…The sensitivity of this composite prepared in this study was quite similar to the values found for the polymer system with 30 wt% of conductive contents prepared by Muller et al 23 , Souza Jr., Michel and Soares 11 and Barra et al 12 . It is important to note that the compressive stress range applied in this work (0.25 MPa) is significantly lower than those reported in literature (from 0 to 10 MPa) 8,[15][16][23][24] , as shown in Table 3. On the other hand, the sensitivity of PBAT/Mt-PPy is lower when compared to porous materials studied by Xue et al 28 and Wu et al 17 .…”

“…The electrical resistivity of this blend dropped by two orders of magnitude, e.g. from 10 8 to 10 6 Ω cm 24 . Souza, Michel and Soares reported that the electrical resistivity of poly(styrene-butadiene-styrene)/polyaniline blends drops one order of magnitude when a compressive stress from 0 to 4 MPa is applied 11 .…”

“…These materials are composed of an insulating polymer matrix and a dispersed phase of intrinsically conducting polymer (ICP) [10][11][12][13][14] , such as polypyrrole (PPy) or polyaniline (PAni), or carbonaceous fillers, such as carbon black [15][16][17] and graphite 18 . Among available conducting fillers, several works in the literature have reported the use of conducting polymers, especially PPy, for sensing applications 1,5,8,9,[19][20][21][22][23][24][25][26][27][28] . Merlini et al described the development of poly(vinylidene fluoride) (PVDF) / polypyrrole (PPy) blends, and the maximum sensitivity was obtained for a blend with 9 wt% PPy.…”

“…Under compressive stress, the conductive particles come into a closer contact forming a new conducting network. On the other hand, by releasing the compression stress, the conducting network is disrupted, and the electrical conductivity returns to the initial value to that without pressure 24 . The electrical sensitivity and reproducibility of the response of these composites depend on various factors including the structure and properties of the dispersed phase (such as, intrinsically electrical conductivity, aspect ratio and surface area), the properties of the matrix, ICP content, interaction of both polymer phases and dispersion of the ICP into the insulating polymer matrix.…”

Poly(vinylidene fluoride-co-hexafluoropropylene)/polyaniline blends assisted by phosphonium – Based ionic liquid: Dielectric properties and β-phase formation

“…Conducting composites constituted by PVDF or its copolymers and conducting particles such as carbon nanotubes [9][10][11], carbon nanofibers [12], short carbon fiber [13], graphite [14][15] and graphene [16][17][18] have been extensively studied. Intrinsic conducting polymer as polypyrrole [19][20] and polyaniline [21][22][23][24][25][26][27][28] have also been experienced as conducting component in PVDF -based blends. Polyaniline (PAni) is considered one of the most popular conducting polymer due to its unique characteristics which combine environmental stability and good electrical conductivity with low cost of the raw materials and easy synthesis.…”