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Conductive polypropylene/clay/polypyrrole nanocomposites
Polymer Engineering & Science, 2006
Nanocomposites of a new type have been prepared containing a constant amount, 4.8 wt%, of montmorillonite (MMT) in a polypropylene (PP) matrix and different amounts of conducting polypyrrole (PPy) varying from 4.8 to 16.7 wt%. For comparison, polypropylene/ polypyrrole (PP/PPy) composites and MMT/PPy nanocomposites with the same composition ratio were synthesized. All polypropylene-containing composites were synthesized in an aqueous solution of the anionic surfactant dodecylbenzenesulfonic acid (DBSA) or in water/methanol. Chemical oxidative polymerization of pyrrole was used for suspension modification of powdered PP, MMT, or mixtures of PP and MMT particles using ferric chloride as oxidant. To investigate the influence of the primary MMT particle structure on conductivity, three types of sodium MMT were used for the preparation of MMT/PPy nanocomposites. Wide angle X-ray scattering (WAXS) studies confirmed the intercalation of conducting PPy into MMT layers. The amount of PPy influences the final conductivity of the composites and nanocomposites. The nanocomposite (PP/4.8 wt% MMT)/PPy containing 16.7 wt% PPy reaches a conductivity of 4.8 ؋ 10 ؊2 S cm ؊1 , i.e. more than one order of magnitude higher than the conductivity of the clay-free composite, PP/16.7 wt% PPy prepared as a suspension in water containing the same anionic surfactant, dodecylbenzenesulfonic acid. Thermogravimetric analysis (TGA) proved that the presence of PPy increases the thermal stability of PP/PPy composites as well as (PP/4.8 wt% MMT)/PPy nanocomposites.
Preparation and characterization of electrically conductive polypropylene/polypyrrole composites
European Polymer Journal, 1996
Epoxy composite of different content graphene oxide (GO) from (1.5 vol% to 6 vol%) have been fabricated at (25°C) temperature. The (GO)/ epoxy composite were studied in terms of electrical properties. The electrical conductivity of the composites is rises from 1.047 Â 10 À10 (S/m) at pure epoxy to 3.37 Â 10 À10 (S\m) when the GO content is increased to 6 vol%, scanning electron microscopy (SEM) was shown the interface between the composite composition. The conductivity of composites have been showed the transition from insulation to conduction when took place for graphene oxide to the pure epoxy resin.
Journal of Applied Polymer Science, 2012
Nowadays, nanocomposites are a special class of materials having unique physical properties and wide application potential in diverse areas. The present research work describes an efficient method for synthesis of a series of polypyrrole/titanium dioxide (PPy/TiO 2) nanocomposites with different TiO 2 ratios. These nanocomposites were prepared by one-step in situ deposition oxidative polymerization of pyrrole hydrochloride using ferric chloride (FeCl 3) as an oxidant in the presence of ultra fine grade powder of anatase TiO 2 nanoparticles cooled in an ice bath. The obtained nanocomposites were characterized by Fourier-transform infrared (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscope (SEM) techniques. The obtained results showed that TiO 2 nanoparticles have been encapsulated by PPy with a strong effect on the morphology of PPy/TiO 2 nanocomposites. Also, the synthesized PPy/TiO 2 nanocomposites had higher thermal stability than that of pure PPy. The investigation of electrical conductivity of nanocomposites by four-point probe instrument showed that the conductivity of nanocomposite at low TiO 2 content is much higher than of neat PPy, while with the increasing contents of TiO 2 , the conductivity decreases.
Polymer, 2000
The electrical conductivity of chemically prepared polypyrrole in aqueous solution was found to be strongly dependent on the preparation technique and polymer additive. Owing to the hygroscopic nature of polypyrrole, it is essential to remove residual water. Accordingly, the conductivity can be enhanced by about two orders of magnitude when using a preparation technique that includes a washing treatment with organic solvents and drying under vacuum at elevated temperatures to attain maximum removal of water. Thus, the electrical conductivity of polypyrrole is affected not only by reported factors such as the ratio of oxidant to pyrrole, reaction temperature, and reaction time, but also by the preparation technique. Additionally, a significant enhancement of the conductivity up to 90 S cm Ϫ1 by using of poly(ethylene glycol) as an additive during the polymerization could be achieved. ᭧
Effects of preparation temperature on the conductivity of polypyrrole conducting polymer
Journal of Chemical Sciences, 2002
An attempt has heen made to investigate the effect of temperature on the conductivity of polypyrrole conducting polymer films prepared by an electrochemical method in an aqueous medium using camphor sulfonate as the dopant. The polymer was grown from aqueous solutions employing a range of temperatures (l–60°C). It was found that with increase in temperature the conductivity decreased and the
Electrical Conductivity Measurement Studiesof Polyacrylonitrile/Polypyrrole (PAN/Ppy)Composite
International Journal of Advanced Research in Electrical, Electronics and Instrumentation Energy, 2014
An electrically conducting composite material polyacrylonitrile/Polypyrrole (PAN/Ppy) was prepared by sol-gel method. The temperature dependence of the DC electrical conductivity was measured on compressed pellets by using a 4-in-line-probe dc electrical conductivity-measuring instrument. The conductivity values lies in the semiconductor region, i.e., 10-2–10-4 S cm-1 and follow the Arrhenius equation. The thermal stability of the composite material (HCl treated) in terms of dc electrical conductivity retention was studied under isothermal conditions (at 50, 70, 90, 110, 130 and 150 °C) at 15 min intervals. The stability of the material (HCl treated) in terms of electrical conductivity retention was also monitored for five cycles for increasing temperatures at 1 h intervals. The composite material was found thermally and environmentally stable in terms of DC electrical conductivity retention.
Synthetic Metals, 2004
The conducting composites were prepared by chemical oxidative polymerization using pyrrole and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) or sulfonated-poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) in chloroform. The pyrrole was protonated and polymerized using iron(III) chloride (FeCl 3). The electrical conductivities of PPy/SPPO composites were increased up to 1 order with the amount of PPy compared to PPy/PPO composites. The introduction of sulfuric group to PPO results in the Coulombic interaction between each phase of composites. As a result, the electrical conductivities might be increased due to the effect of miscibility between each phase. The electrical conductivity of PPy/SPPO composite was increased up to 2.14 S/cm with amount of 25 wt.% PPy. The performance of charge-discharge of PPy/SPPO electrode was much higher than that of PPy/PVdF electrode because SPPO act as a dopant as well as a binder.
IOP Conference Series: Materials Science and Engineering, 2019
A conductive Polypyrrole (PPy) has been successfully synthesized and characterized. The PPy was prepared through oxidative chemical polymerization using ammonium peroxydisulfate (APS) as an oxidizing agent in aqueous media. The reaction is prepared without heating. Anionic and non-ionic emulsifiers, sodium dodecyl sulfate (SDS), nonylphenol (NP) ethoxylate (EO) with 10 mole EO were respectively used during polymerization to increase the electrical conductivity. The FTIR spectrum of PPy indicates a change in the absorbance peaks of pyrrole monomer at 1530 cm−1and those in the range region of 1100 - 1000 cm−1. With the SDS addition, the temperature of solution increased with reaction time reached the highest 35 °C within 2 minutes reaction. The pH value of an SDS added solution was 3.3 higher than that of SDS free solution (1.8). The addition of SDS was also to change the color changing during the polymerization reaction. The final characteristic of PPy by measuring the electrical con...
Characterization of Polypyrrole−Silver Nanocomposites Prepared in the Presence of Different Dopants
The Journal of Physical Chemistry B, 2005
Conducting polypyrrole (PPy) powder synthesized by using FeCl 3 × 6 H 2 O and/or Fe(NO 3 ) 3 oxidants was impregnated in silver salt solutions. The stability and decomposition of the material was followed by thermogravimetric measurements. The total silver content was determined by atom absorption spectroscopy (ICP-AAS). The heat and electric conductivities of the composites were measured and correlated with the silver content. The incorporated silver was speciated and measured by X-ray diffraction (XRD). The spectra proved that the chemical state of the silver incorporated into the composite depends on the anion used in the polymerization process. In the case of the polymerization in a nitrate ion containing solution, the impregnation leads exclusively to the formation of metallic silver. The size distribution of the AgCl and Ag nanoparticles, determined from transmission electron microscopy (TEM) pictures in the different composites, proves the formation of a rather uniform species below 10 and 7 nm, respectively. The observations can be correlated with the different interactions in the PPy-chloride/nitrate-silver systems. The redox type interaction based conclusions can be considered as a guide during the preparation of other metal-conducting polymer composites.
A conducting composite of polypyrrole I. Synthesis and characterization
Synthetic Metals, 1994
The success of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry for the characterization of polymer structures and for the determination of average molecular weights and distributions depends on the use of a proper sample/matrix preparation protocol. This work examines the effect of solvents, particularly solvent mixtures, used to prepare polymer, matrix, and cationization reagent solutions, on MALDI analysis. It is shown that the use of solvent mixtures consisting of polymer solvents does not have a significant effect on the molecular weight determination of polystyrene 7000 and poly(methyl methacrylate) 3750. However, solvent mixtures containing a polymer nonsolvent can affect the signal reproducibility and cause errors in average weight measurement. This solvent effect was further investigated by using confocal laser fluorescence microscopy in conjunction with the use of a fluorescein-labeled polystyrene. It is demonstrated that sample morphology and polymer distribution on the probe can be greatly influenced by the type of solvents used. For sample preparation in MALDI analysis of polymers, it is important to select a solvent system that will allow matrix crystallization to take place prior to polymer precipitation. The use of an excess amount of any polymer nonsolvent should be avoided. (J Am Soc Mass Spectrom 1998, 9, 1303-1310