Electrical properties poly pyrroles

S. Brahim and A. Guiseppi-Elie, Electroconductive hydrogels Electrical properties of poly-pyrrole-poly(HEMA) and electrochemical composites. Electroanalysis, 17(7), 556-570... 

Poly(pyrrole), known for over 50 years, is one of the most studied poly-mers. First synthesized by electrochemical polymerization in 1968, poly(pyrrole) is electrically conductive, stable, and insoluble when doped. The mechanism of its electrosynthesis was studied by Genies et Thin films of electropolymerized poly(pyrrole) (< 0.1 fim) are electroactive, and they can be switched between the neutral and the oxidized state at +0.1 V versus SCE. This particular property of polypyrrole can be applied in constructing conductivity... 

The electrical properties of clay-containing nanohybrids of PVK and poly(pyrrole) have been assessed [224]. Clay hybrids were prepared by mechanical grinding of the monomers with montmorillonite and subsequent polymerization. 

A number of conjugated heterocyclic polymers, viz., poly(pyrrole) [9], poly(p-phenylene) [10], poly(thiophene) [11], and poly(aniline) [12] are also electrically conducting and continue to be developed and studied for electrochromic devices [13-14 see also the companion chapter in this volume] and ion switching devices [15-16], among others. Polymer films with high electrical conductivity have been generated by electrochemical polymerization of benzenoid, nonbenzenoid and heterocyclic aromatics, in particular from the derivatives of pyrrole, thiophene, carbazole, azulene, pyrene, triphenylene and aniline. The electrochemical approach for making these films is very versatile and it provides a facile way to vary the properties of the films. The realization of the applications for each electroactive polymer depends on the control and particularly the enhancement of the... 

The experimental conditions of preparation deeply affect the electrical properties of the final material. A polypyrrole sample with a conductivity of 328 S cm has been obtained by careful control of the oxidation potential in a binary solution of acetonitrile and methanol [88]. Different chemical characteristics of poly pyrrole are obtained by varying the initial concentrations of Fe " and pyrrole in the polymerization solution [89]. Polypyrrole obtained by chemical oxidation is usually in the form of a black powder. Freestanding poly pyrrole films were prepared at room... 

Electrical properties have been reported on numerous carbon fiber-reinforced polymers, including carbon nanoflber-modified thermotropic liquid crystalline polymers [53], low-density polyethylene [54], ethylene vinyl acetate [55], wire coating varnishes [56], polydimethyl siloxane polypyrrole composites [50], polyacrylonitrile [59], polycarbonate [58], polyacrylonitrile-polycarbonate composites [58], modified chrome polymers [59], lithium trifluoromethane sulfonamide-doped polystyrene-block copolymer [60], boron-containing polyvinyl alcohols [71], lanthanum tetrafluoride complexed ethylene oxide [151, 72, 73], polycarbonate-acrylonitrile diene [44], polyethylene deoxythiophe-nel, blends of polystyrene sulfonate, polyvinyl chloride and polyethylene oxide [43], poly-pyrrole [61], polypyrrole-polypropylene-montmorillonite composites [62], polydimethyl siloxane-polypyrrole composites [63], polyaniline [46], epoxy resin-polyaniline dodecyl benzene sulfonic acid blends [64], and polyaniline-polyamide 6 composites [49]. 

Poly (pyrrole) and poly(thiophene), both first described in 1963 as electrically conducting materials [5], experienced a renaissance when Diaz and Street gave a new attention to the electrochemical oxidation of pyrrole and Gamier to the poly(thiophene) field transistor. Polyfphenylenevinylene), poly(aniline), poly(phenylenesulfide), poly(carbazole), poly(in-dole), poly(pyrene) and polyene fulvene are just a few of the large number of electrically conducting polymers with specific properties and interest [20]. 

Chronakis IS, Grapenson S, Jakob A (2006) Conductive poly pyrrole nanofibers via electrospinning electrical and morphological properties. Polymer 47(5) 1597-1603. doi 10.1016/j.polymer.2006.01.032... 

The most studied systems have been polypyrrole/ PVC blends [372-5]. The electrochemical polymerization of pyrrole on a platinum electrode covered with a film of PVC produces a dark-brown, ductile and flexible composite polymer film with an electrical conductivity comparable to polypyrrole (5-50 S cm ), and mechanical properties very similar to PVC. Bargon et al. [373] have observed that the mechanical properties of these PPy/PVC blends can be further improved by the addition of poly(chloroprene) rubber as a plasticizer. 

Conducting polymers formed by the polymerization of the five-membered aromatic ring heterocycles pyrrole and thiophene (11) are well established. These ring systems have been adapted for LB deposition, and LB properties of the preformed polymers quinquethienyl (12) [28] and poly(3-dodecylthiophene) (13)[29] have been reported along with electrical behaviour. 

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