Conducting polyfurans by electropolymerization of oligofurans (original) (raw)

Polyfuran conducting polymers: Synthesis, properties, and applications

Synthetic Metals, 2008

In this review, polyfuran (PFu) synthesis methods and the nucleation mechanism; the electrochemical, structural, morphological, and magnetic properties of PFu; thermal behavior; theoretical calculations on PFu, as well as its applications reported to date, have been compiled. Not only PFu homopolymers have been reviewed, but also PFu co-polymers, PFu bipolymers, and PFu composites. The results are listed, discussed, and compared. It is hoped that this assembly of all the relevant data might enhance knowledge about this conducting polymer and lead to new research fields.

ESR and conductivity investigations on electrochemically synthesized polyfuran and polythiophene

Journal of Physics and Chemistry of Solids, 2000

ESR studies have been carried out on ClO4−-doped polyfuran (PF) and BF4−-doped polythiophene (PT) films synthesized by constant potential electrolysis. Variation of spin concentration and linewidth of ESR signal with temperature were investigated. The temperature dependence of conductivity supported the Mott's variable range hopping mechanism for PT and PF freestanding films. Temperature dependence of activation energy indicated that hopping is the dominating mechanism of charge transport.

Theoretical study to evaluate polyfuran electrical conductivity and methylamine, methoxy substituent effects

Journal of Molecular Structure-theochem, 2008

There is a lot of interest from the scientific and technological point of view in the use of furan-based polymer molecules as electroconducting polymers despite some difficulties in their synthesis. In order to shed some light into the factors that affect the electrical conducting properties of furan-based polymers a theoretical study on methylamine and methoxy mono-substituted furan oligomers was performed. The purpose in choosing these substituents is founded on their electro-donning nature, which could have a favorable role on the reactivity of polyfuran molecules and have a direct effect on the band gap (E g ) and ionization potential (IP) facilitating in this way the synthesis of furan-based polymers. In addition the substituents were tested on different ring positions. All molecular geometries were optimized at B3LYP/6-31G(d) level of theory. Energy gaps between HOMO and LUMO orbitals and IPs were obtained from these calculations. IPs, and E g s of the polymers were obtained by extrapolating those of the oligomers to the inverse chain length equal to zero (1/N = 0). The theoretical calculations show that substituted oligomers are stable and have a minor value of E g and IP in their ground and doubly charged states. It was found that the carbon-carbon bond lengths in the oligomers are distorted in the charged states. This is due to the partial loss of ring aromaticity which forces some bond lengths to shorten or lengthen probably caused by the formation of quinoid-like structures.

Electrochemical behaviour of conducting polyfuran derivatives containing pyrrole, thiophene and ethylenic spacers

European Polymer Journal, 2000

Two types of conducting polymer composites comprising polypyrrole (PPy) (filler) dispersed in a polyimide (PI) (matrix) and bilayered conducting polymer/PI composites, were successfully formulated. Electrochemical deposition of the PPy/PI composite was accomplished by initially depositing PPy onto the working electrode, and then casting a layer of PI onto the modified electrode. The PPy/PI composite was also formulated by first casting a PI film onto the bare electrode followed by electrochemical deposition of PPy. Poly(N-ethylaniline)/PI composites were prepared by initially depositing a thin layer of poly(N-ethylaniline) onto the substrate (AA 2024-T3) and then casting a layer of PI resin onto the modified substrate. The composite coatings were characterised by advanced analytical techniques, such as reflection absorption infrared spectroscopy (RAIR), SEM, dc polarisation studies and electrochemical impedance spectroscopy. SE/S275 Drs Iroh

Electrochemical polymerization of furan and 2-methylfuran

Synthetic Metals, 1999

Conductive polyfuran and poly 2-methyl furan are prepared by controlled potential electrolysis in acetonitrile at room temperature. It is found that conductivity of polyfuran decreased by factor of 4 when methyl group is present in the a position. Temperature effect on the rate of polymerization of furan is studied by cyclic voltammetry technique and an increase in the initial rate of polymerization was observed with increasing temperature. Apparent activation energy of electrochemical polymerization of furan was found to be 7.5 kJrmole. The mechanism of electrochemical polymerization was investigated by in situ ESR.

Colored electrically conducting polymers from furan, pyrrole, and thiophene

Journal of Polymer Science Part A-1: Polymer Chemistry, 1967

Furan, pyrrole, and thiophene were polymerized under catalysis by trichloro-and trifluoroacetic acid to produce colored polymers which were characterized by various methods, including electronic and proton magnetic resonance spectra and electrical conductances of deeply colored trichloroacetic acid adducts. The predominant repeat units of these polymers are of the same type as those of deeply colored cyclopentadiene polymers, except that a CH2 group is replaced by 0, NH, or S.

Electrogeneration of conducting poly(2,5-di-(-2-thienyl)-furan)

Journal of Electroanalytical Chemistry, 1998

The electrochemical behaviour of 2,5-di-(-2-thienyl)-furan (SOS) on Pt has been studied in 0.2 M LiClO 4 + acetonitrile+0.25% (v/v) water solutions by cyclic voltammetry, chronoamperometry and chronopotentiometry. The monomer oxidises at more positive potentials than 0.7 V vs. AgAgCl giving a dark-blue film. The most reproducible film weights are obtained by flowing a constant current lower than 1.0 mA cm − 2. The resulting insoluble oxidised films are electroactive and electrochromic. Their control voltammograms exhibit two redox processes attributed to polaronic and bipolaronic states, together with an intermediate reduction shoulder ascribed to radical cation pairs. Electropolymerisation kinetics have been followed by 'ex situ' ultramicrogravimetry, giving a maximum productivity of 1.85 mg mC − 1. The oxidised poly(SOS) contains polarons and electroinactive positive charges, both compensated with perchlorate counterions. The reduced poly(SOS) has been obtained in the same electrolyte by applying a constant potential of 0 V to oxidised films. A partial electrodissolution of films is observed during their reduction. The electroinactive charges present in the resulting reduced state cause its insolubility in the medium. Densities, conductivities and solubilities in different organic solvents of both oxidised and reduced poly(SOS) have been determined. Short linear oligomers formed during SOS electropolymerisation have been detected in the saturated solutions of reduced poly(SOS) by mass spectrometry-fast atom bombardment.