Investigation of structure and conductivity properties of polyaniline synthesized by solid–solid reaction (original) (raw)

Synthesis and Characterization of Polyaniline Based Conducting Polymers

Present work deals with the synthesis of Polyaniline, polynitro aniline, poly m-toludine and poly o-toludine polymers by chemical oxidation method using ammonium per sulfate as chemical oxidant. The yield of all polymers was higher than 90%.The synthesized polymeric material have been characterized by FTIR spectroscopy. FTIR and SEM studies of polymer show the structural and slight morphological changes with change in substituent in monomer units

Synthesis and Characterization of Polyaniline Based Conducting Polymers line

Present work deals with the synthesis of Polyaniline, polynitro aniline, poly m-toludine and poly o-toludine polymers by chemical oxidation method using ammonium per sulfate as chemical oxidant. The yield of all polymers was higher than 90%.The synthesized polymeric material have been characterized by FTIR spectroscopy. FTIR and SEM studies of polymer show the structural and slight morphological changes with change in substituent in monomer units.

Polyaniline. Preparation of a conducting polymer(IUPAC Technical Report)

Pure and Applied Chemistry, 2002

Eight persons from five institutions in different countries carried out polymerizations of aniline following the same preparation protocol. In a "standard" procedure, aniline hydrochloride was oxidized with ammonium peroxydisulfate in aqueous medium at ambient temperature. The yield of polyaniline was higher than 90 % in all cases. The electrical conductivity of polyaniline hydrochloride thus prepared was 4.4 ± 1.7 S cm-1 (average of 59 samples), measured at room temperature. A product with defined electrical properties could be obtained in various laboratories by following the same synthetic procedure. The influence of reduced reaction temperature and increased acidity of the polymerization medium on polyaniline conductivity were also addressed. The conductivity changes occurring during the storage of polyaniline were monitored. The density of polyaniline hydrochloride was 1.329 g cm-3. The average conductivity of corresponding polyaniline bases was 1.4 x10­8 S cm-1, the ...

The Effect of Oxalic Acid as a Doping Agent on the Conductivity of Polyaniline

Scientific Research Journal, 2019

This study investigates the effect of oxalic acid at different concentrations as doping agent on the electrical properties of polyaniline (PANI). The polymerization of aniline to produce PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and 0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6 Scm-1.

Morphology and electrical properties of hybrid and sulphonated oxalic acid-doped polyaniline

Synthetic Metals, 2010

Polyaniline-polyethylene glycol2000 (PAni-PEG2000) hybrid and sulphonated polyaniline (SPAni) were prepared using oxalic acid as dopant and potassium permanganate as oxidant. The properties of these two conductive polymers were studied in comparison with pure polyaniline (PAni) prepared using the same conditions. The investigated polymers were characterized using FTIR, UV-vis, TGA, TEM, SEM, XRD and their electrical conductivities were also investigated. The morphology of pure polymer was found to be flat ribbon-like form, while presence of polyethylene glycol led to the formation of separate nanospheres. The three polymer samples have different degrees of crystallinity, the highest degree is for SPAni. Unexpectedly, electrical conductivity is in the order SPAni > PAni-PEG2000 > PAni, aging of PAni increases gradually the conductivity of the polymer from 0.0056 to 0.023 S cm −1 and the increase of temperature gradually decreases the conductivity.

Chemical synthesis and characterization of some conducting polyaniline derivatives: Investigation of the effect of protonation medium

Journal of Applied Polymer Science, 2002

Poly(o‐toluidine) (POT) and poly(2‐chloroaniline) (P2ClAn) emeraldine salts were synthesized chemically by using formic (HCOOH), acetic (CH3COOH), propionic (C2H5COOH), and boric (H3BO3) acids. Ultraviolet‐visible absorption spectra (UV–Vis) analysis results indicated that POT has the better protonation effects than P2ClAn. Among the POTs synthesized using the four different acids, POT(H3BO3) showed the least protonation effect. The conductivities of prepared polymers were measured by a four‐probe technique. The highest conductivities were obtained in POTs synthesized by using formic, acetic, and propionic acids. Magnetic susceptibility measurements of the polymer salts were analyzed by using Gouy scale and it was found that POT(CH3COOH) and POT(C2H5COOH) salts are of bipolaron structure; other polymer salts are of polaron structure. The characterization of the polymers were investigated by Fourier infrared spectroscopy (FTIR), UV–Vis, thermogravimetric analysis, and scanning electr...

Electrical Conductivity of Conductive Polymer Polyaniline (PANI-ES) Preparation by Chemical Oxidative Method

Conductive polymer as Polyaniline (PANI-ES) prepared by chemical oxidation polymerization method at room temperature and studied the effect the dopant sulfuric acid on the structure of the polymer, which prepared with molarity of sulfuric acid (1M), the changes taking place were follow-up by the following measurements: FESEM, FT-IR, I-V character. The diagnosis of the output polymer films by using infrared spectroscopy FT-IR, for doped samples with 1M of sulfuric acid observed change in the intensity of emission opposite the wave number corresponding to each bond, while not noticed any change in the position of the bonds with appearance anew peak return to SO 4 compound. By the FESEM properties of the surface study using the topography FESEM (Field Emission Scanning Electronic Microscopic) and calculated the particle revealed, that the compound has micro granular affected with the presence of acid. Electrical characteristic study by using the two-probe manner, it found that the samples had ohmic plots in which high linear coefficients. The doped samples of polymer had a highest conductivity of 2.98x10-4 S.cm-1 at 383 K, which observed for the H 2 SO 4 doped sample, which shows that was more prominent of localized salt in polymer.

Effects of the polymerization temperature on the structure, morphology and conductivity of polyaniline prepared with ammonium peroxodisulfate

European Polymer Journal, 2013

Polyaniline (PANI) samples were prepared by the oxidation of aniline with ammonium peroxodisulfate in a reaction vessel placed in a bath thermostated to particular temperature, T b , from À20°C to 40°C. Temperature-time profiles of reaction mixtures were monitored except for the reaction at À20°C that proceeded in the solid state. The temperature regime was found to influence the molecular structure, morphology, crystallinity and electrical conductivity of PANI. The increase in T b results in an increased content of meanwhile unspecified structure defects in the formed PANI chains (the presence of attached self-doping groups is improbable), decreased crystallinity, toughness and compactness of PANI microparticles and increased steepness of the temperature dependence of PANI conductivity. The PANI prepared in the solid-state polymerization at À20°C shows, besides a rather high crystallinity, the unusually high position of the quinonoid band maximum: 643 nm, which suggests a high regularity of its chains. A correlation between the temperature dependence of PANI conductivity at low temperatures (range from 13 to 318 K) on one hand and the temperature regime of PANI preparation on the other hand, is reported for the first time. The dependences obtained only poorly meet the variable random hopping model.

Optimization of the conductivity and yield of chemically synthesized polyaniline using a design of experiments

Journal of Applied Polymer Science, 2013

The electrical conductivity and yield of polyaniline (PANi) were optimized using a design of experiments (DOE). PANi samples were synthesized by the chemical oxidative polymerization of aniline using methane sulfonic acid as the dopant acid and ammonium persulfate as the oxidant. The main factors in the synthesis of PANi that can affect the conductivity were identified as (i) the concentration of dopant acid, (ii) oxidant-to-monomer ratio, and (iii) the addition rate of oxidant to monomer. Using a Box-Behnken DOE method the regression equation, main effects plots, contour plots, and optimization plots for conductivity and yield were generated and analyzed. Under the optimized conditions of dopant acid concentration of 0.9M, an oxidant addition rate of 30 mL/h and an OM ratio of 0.9, PANi with a conductivity of 1.95 S/cm and yield of 95% was obtained. The observed trends in the four-point probe conductivity measurements were correlated with the polymer structure using fourier transform infrared spectroscopy, X-ray diffraction studies, and scanning electron microscopy.