Comparison of poly(o‐anisidine) and poly(o‐anisidine‐co‐aniline) copolymer synthesized by chemical oxidative method

In this study, poly(o‐anisidine) [POA], poly(o‐anisidine‐co‐aniline) [POA‐co‐A], and polyaniline [PANi] were chemically synthesized using a single polymerization process with aniline and o‐anisidine as the respective monomers. During the polymerization process, p‐toluene sulfonic acid monohydrate was used as a dopant while ammonium persulfate was used as an oxidant. N‐methyl‐pyrolidone (NMP) was used as a solvent. We observed that the ATR spectra of POA‐co‐A showed features similar to those of PANi and POA as well as additional ones. POA‐co‐A also achieved broader and more extended UV–vis absorption than POA but less than PANi. The chemical and electronic structure of the product of polymerization was studied using Attenuated Total Reflectance spectroscopy (ATR) and UV–visible spectroscopy (UV–vis). The transition temperature of the homopolymers and copolymers was studied using differential scanning calorimetry and the viscosity average molecular weight was studied by using dilute solution viscometry. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of conducting copolymers from aniline and o‐anisidine in HCl solutions

Conducting poly(aniline‐co‐o‐anisidine) (PAS) films with different ratios of aniline units in the polymer chain were prepared by oxidative polymerization of different molar ratios of aniline and o‐anisidine in 1 M HCl using cyclic voltammetry. Due to the much higher reactivity of o‐anisidine, the structure and properties of PASs were found to be dominated by the o‐anisidine units. The polymerization of poly‐o‐anisidine and PASs followed zero‐order kinetics with respect to formation of the polymer (film thickness) and the autocatalytic polymerization of aniline was completely inhibited. In contrast to polyaniline, a decrease in the polymerization temperature was found to increase the amount of copolymer formed and its redox charge. The presence of aniline units in PASs led to a pronounced increase in the molecular weight and conductivity, and a decrease in the solubility in organic solvents. Repetitive charging/discharging cycles showed that PASs resist degradation more than polyaniline. Copyright © 2003 Society of Chemical Industry     

Synthesis and characterization of poly(o‐anisidine)/V2O5 and poly(o‐anthranilic acid)/V2O5 nanocomposites

Poly(o‐anisidine)/V₂O₅ and poly(o‐anthranilic acid)/V₂O₅ nanocomposites were prepared by in situ intercalative polymerization, and the structure and electrical properties of these nanocomposites were investigated using GPC, TGA, XRD, TEM, FTIR, UV‐vis as well as conductivity measurement. The results show that the steric effect and nature of the substituting groups in the aromatic ring has an influence on the structure and electrical properties of the nanocomposites. Poly(o‐anisidine) or poly(o‐anthranilic acid) exists as a monolayer of outstretched chains in the gallery of the V₂O₅ xerogel owing to the confined environment in the nanometer‐size gallery. And intercalation of poly(o‐anisidine) or poly(o‐anthranilic acid) can improve the conductivity of V₂O₅ xerogel. Copyright © 2005 Society of Chemical Industry     

Melt processable conducting poly(aniline‐co‐o‐anisidine)/linear low‐density polyethylene composites with ethylene‐acrylic acid copolymer as compatibilizer

Conducting composites of aniline/o‐anisidine copolymer doped by dodecylbenzenesulfonic acid (P(An‐co‐oAs)‐DBSA), linear low‐density polyethylene (LLDPE), and ethylene–acrylic acid copolymer (EAA) as compatibilizer were prepared by melt processing. The effects of composition on electrical conductivity, resistivity‐temperature characteristic, and mechanical properties were also investigated. The electrical conductivity of ternary composites markedly increased due to compatibilizition and protonation effect of the EAA. The SEM micrograph shows that the compatibility between the P(An‐co‐oAs)‐DBSA and the LLDPE matrix is enhanced after the introduction of EAA. The positive temperature coefficient of resistivity characteristic is observed. Tensile strength of P(An‐co‐oAs)‐DBSA/LLDPE/EAA composites is improved, compared with P(An‐co‐oAs)‐DBSA/LLDPE composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1511–1516, 2005     

Glucose oxidase electrodes of poly(o‐anisidine), poly(o‐toluidine), and their copolymer as biosensors: A comparative study

Thin films of poly(o‐anisidine) (POA), poly(o‐toluidine) (POT), and their copolymer poly(o‐anisidine‐co‐o‐toluidine) (POA‐co‐POT) were electropolymerized in solutions containing 0.1M monomer(s) and 1M H₂SO₄ as an electrolyte through the application of a sequential linear potential scanning rate of 50 mV/s between ?0.2 and 1.0 V versus an Ag/AgCl electrode on a platinum electrode. A simple technique was used to construct glucose sensors through the entrapment of glucose oxidase (GOD) in thin films of POA, POT, and their copolymer POA‐co‐POT, which were electrochemically deposited on a platinum plate in phosphate and acetate buffers. The maximum current response was observed for POA, POT, and POA‐co‐POT GOD electrodes at pH 5.5 and at a potential of 0.60 V (vs Ag/AgCl). The phosphate buffer yielded a fast response in comparison with the acetate buffer in amperometric measurements. The POT GOD electrode showed a fast response and was followed by POA‐co‐POT and POA GOD electrodes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1877–1884, 2004     

Synthesis and characterization of self‐doped poly(aniline‐co‐aminonaphthalene sulfonic acid) nanotubes

Self‐doped poly(aniline‐co‐aminonaphthalene sulfonic acid) (PANI‐ANSA) was synthesized by the copolymerization of 5‐aminonaphthalene‐2‐sulfonic acid (ANSA) and aniline. Scanning electron microscopy and transmission electron microscopy showed that the morphology of PANI‐ANSA synthesized at a high molar ratio of aniline to ANSA was nanotubular, but at a low molar ratio, only a granular morphology formed. A possible formation mechanism for nanotubes was proposed. PANI‐ANSA had better thermal stability than HCl‐doped polyaniline; the highest onset decomposition temperature was as high as 340°C because of ? SO₃H linked with the polymer backbone by a covalent bond. PANI‐ANSA was partially soluble in basic solutions, and its conductivity was between 10^?2 and 10^?4 S/cm, depending on the sulfonation degree. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1297–1301, 2003     

Investigation of charge transport properties in conducting copolymers of aniline with 3‐aminobenzenesulfonic acid for their applications as antistatic encapsulation materials blended with low‐density polyethylene

The electrostatic charge dissipative (ESD) properties of conducting self‐doped and PTSA-doped copolymers of aniline (AA), o‐methoxyaniline (methoxy AA) and o‐ethoxyaniline (ethoxy AA) with 3‐aminobenzenesulfonic acid (3‐ABSA) blended with low‐density polyethylene (LDPE) were investigated in the presence of external dopant p‐toluenesulfonic acid (PTSA). Blending of copolymers with LDPE was carried out in a twin‐screw extruder by melt blending by loading 1.0 and 2.0 wt% of conducting copolymer in the LDPE matrix. The conductivity of the blown polymers blended with LDPE was in the range 10^?12–10^?6 S cm^?1, showing their potential use as antistatic materials for the encapsulation of electronic equipment. The DC conductivity of all self‐doped homopolymers and PTSA‐doped copolymers was measured in the range 100–373 K. The room temperature conductivity (S cm^?1) of self‐doped copolymers was: poly(3‐ABSA‐co‐AA), 7.73 × 10^?4; poly(3‐ABSA‐co‐methoxy AA), 3.06 × 10^?6; poly(3‐ABSA‐co‐ethoxy AA), 2.99 × 10^?7; and of PTSA‐doped copolymers was: poly(3‐ABSA‐co‐AA), 4.34 × 10^?2; poly(3‐ABSA‐co‐methoxy AA), 9.90 × 10^?5; poly(3‐ABSA‐co‐ethoxy AA), 1.10 × 10^?5. The observed conduction mechanism for all the samples could be explained in terms of Mott's variable range hopping model; however, ESD properties are dependent upon the electrical conductivity. The antistatic decay time is least for the PTSA‐doped poly(3‐ABSA‐co‐AA), which has maximum conductivity among all the samples. © 2013 Society of Chemical Industry     

Synthesis and characterization of conducting homopolymers and copolymers of o‐anisidine and o‐toluidine in inorganic and organic supporting electrolytes

The influence of inorganic and organic supporting electrolytes on the electrochemical, optical, and conducting properties of poly(o‐anisidine), poly(o‐toluidine), and poly(o‐anisidine‐co‐o‐toluidine) thin films was investigated. Homopolymer and copolymer thin films were synthesized electrochemically, under cyclic voltammetry conditions, in aqueous solutions of inorganic acids (H₂SO₄, HCl, HNO₃, H₃PO₄, and HClO₄) and organic acids (benzoic acid, cinnamic acid, oxalic acid, malonic acid, succinic acid, and adipic acid) at room temperature. The films were characterized by cyclic voltammetry, ultraviolet–visible spectroscopy, and conductivity measurements with a four‐probe technique. The ultraviolet–visible spectra were obtained ex situ in dimethyl sulfoxide. The optical absorption spectra indicated that the formation of the conducting emeraldine salt (ES) phase took place in all the inorganic electrolytes used, whereas in organic acid supporting electrolytes, ES formed only with oxalic acid. Moreover, the current density and conductivity of the thin films was greatly affected by the nature and size of the anion present in the electrolyte. For the copolymer, the conductivity lay between the conductivity of the homopolymers, regardless of the supporting electrolyte used. The formation of the copolymer was also confirmed with differential scanning colorimetry. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2634–2642, 2003     

Electrochemical preparation of poly(2‐bromoaniline) and poly(aniline‐co‐2‐bromoaniline) in acetonitrile

Electrochemical preparation of poly(2‐bromoaniline) (PBrANI) and poly(aniline‐co‐2‐bromoaniline) [P(An‐co‐2‐BrAn)] was carried out in an acetonitrile solution containing tetrabutylammonium perchlorate (TBAP) and perchloric acid (HClO₄). The cyclic voltammograms during the copolymerization had many features similar to those for the usual polymerization of aniline. The copolymer exhibits a higher dry electrical conductivity value than that of PBrANI and a lower one than that of PANI. The observed decrease in the conductivity of the copolymer relative to PANI is attributed to the incorporation of bromine moieties into the polyaniline chain. The structure and properties of the polymer and copolymer were elucidated using cyclic voltammetry (CV), FTIR, and UV‐vis spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2460–2468, 2003     

Corrosion protective bi‐layered composites of polyaniline and poly(o‐anisidine) on low carbon steel

Bi‐layered composites of polyaniline (PANI) and poly(o‐anisidine) (POA) were investigated for corrosion protection of low carbon steel (LCS). In this work, homopolymers and bi‐layers of PANI and POA were electropolymerized on LCS from an aqueous salicylate solution by using cyclic voltammetry. These coatings were characterized by cyclic voltammetry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Corrosion tests were carried out in aqueous 3% NaCl solution for LCS coated with PANI, POA, bi‐layered POA/PANI (POA on top of the PANI) or PANI/POA (PANI on top of the POA) composites using open circuit potential (OCP) measurements, potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS). The single layer of PANI and POA protected the LCS in 3% NaCl for 8 and 16 h, respectively. The bi‐layered composite coatings provide effective protection to LCS for a longer time than a single layered PANI or POA coating. However, the corrosion protection offered to LCS depends on the deposition order of polymer layers in the composite. The PANI/POA composite provides better protection to LCS against corrosion than POA/PANI coating. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Electrochemical synthesis of poly(2‐iodoaniline) and poly(aniline‐co‐2‐iodoaniline) in acetonitrile

Poly(2‐iodoaniline) (PIANI) and poly(aniline‐co‐2‐iodoaniline) [P(An‐co‐2‐IAn)] were synthesized by electrochemical methods in acetonitrile solution containing tetrabutylammonium perchlorate (TBAP) and perchloric acid (HClO₄). The voltametry of the copolymer shows characteristics similar to those of conventional polyaniline (PANI), and it exhibits higher dry electrical conductivity than PIANI and lower than PANI. The observed decrease in the conductivity of the copolymer relative to PANI is attributed to the incorporation of the iodine moieties into the PANI chain. The structure and properties of these conducting films were characterized by FTIR and UV‐Vis spectroscopy and by an electrochemical method (cyclic voltametry). Conductivity values, FTIR and UV‐Vis spectra of the PIANI and copolymer were compared with those of PANI and the relative solubility of the PIANI and the copolymer powders was determined in various organic solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1652–1658, 2003     

Chemical copolymerization of aniline with o‐chloroaniline: thermal stability by spectral studies

Poly(aniline‐co‐o‐chloroaniline) salts were synthesized by chemical copolymerization of aniline with o‐chloroaniline using three different acids. The polymer salt samples were heat treated at four different temperatures (150, 200, 275 and 375 °C) and the thermal stability of the polymer salts were studied by conductivity, electron paramagnetic resonance (EPR), infrared (IR) and electronic absorption spectral measurements. The conductivity of the copolymers could be controlled in a broad range from 10 S cm⁻¹ for homopolymer of aniline to 10⁻⁴ S cm⁻¹ for those of o‐chloroaniline. No structural changes took place up to 200 °C and this was confirmed from EPR, IR and electronic absorption spectra. No definite correlation exists between conductivity and spin concentration. © 2000 Society of Chemical Industry     

Synthesis and characterization of a copolymer: Poly(aniline‐co‐fluoroaniline)

In the present article, we report the chemical synthesis and characterization of poly(aniline‐co‐fluoroaniline) [poly(An‐FAn)]. The copolymerization of aniline and 2‐fluoroaniline was carried out by chemical method in acidic medium. The characterization of poly(aniline‐co‐fluoroaniline) was done using FTIR, UV‐visible spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron micrography (SEM), and a four‐points‐probe conductivity method. X‐ray diffraction (XRD) and SEM characterization reveal crystalline nature of doped copolymer compared to undoped copolymer. The observed decrease in the conductivity of the copolymer relative to polyaniline is attributed to the incorporation of the fluoro moieties into the polyaniline chain. The chemically synthesized copolymer shows good solubility in common organic solvents, and is, therefore, technological useful. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1460–1466, 2001     

Anthranilic acid assisted preparation of Fe3O4–poly(aniline‐co‐o‐anthranilic acid) nanoparticles

Magnetic Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were prepared by a novel and simple method: anthranilic acid assisted polymerization. The synthetic strategy involved two steps. First, Fe₃O₄ nanoparticles capped by anthranilic acid were obtained by a chemical precipitation method, and then the aniline and oxidant were added to the modified Fe₃O₄ nanoparticles to prepare well‐dispersed Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles. Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles exhibited a superparamagnetic behavior (i.e., no hysteresis loop) and high‐saturated magnetization (M_s = 21.5 emu/g). The structure of the composite was characterized by Fourier‐transform infrared spectra, X‐ray powder diffraction patterns, and transmission electron microscopy, which proved that the Fe₃O₄–poly(aniline‐co‐o‐anthranilic acid) nanoparticles were about 20 nm. Moreover, the thermal properties of the composite were evaluated by thermogravimetric analysis, and it showed excellent thermal stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1666–1671, 2006     

Synthesis and characterization of N‐ and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]

Poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] was synthesized in an aqueous hydrochloric acid medium with a determined feed ratio by chemical oxidative polymerization. This polymer was used as a functional conducting polymer intermediate because of its side‐group reactivity. To synthesize the alkyl‐substituted copolymer, the initial copolymer was reacted with NaH to obtain the N‐ and O‐anionic copolymer after the reaction with octadecyl bromide to prepare the octadecyl‐substituted polymer. The microstructure of the obtained polymers was characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, and X‐ray diffraction. The thermal behavior of the polymers was investigated by thermogravimetric analysis and differential scanning calorimetry. The morphology of obtained copolymers was studied by scanning electron microscopy. The cyclic voltammetry investigation showed the electroactivity of poly [aniline‐co‐N‐(2‐hydroxyethyl) aniline] and N and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]. The conductivities of the polymers were 5 × 10^?5 S/cm for poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] and 5 ×10^?7 S/cm for the octadecyl‐substituted copolymer. The conductivity measurements were performed with a four‐point probe method. The solubility of the initial copolymer in common organic solvents such as N‐methyl‐2‐pyrrolidone and dimethylformamide was greater than polyaniline. The alkylated copolymer was mainly soluble in nonpolar solvents such as n‐hexane and cyclohexane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Studies on the dielectric properties of poly(o‐toluidine) and poly(o‐toluidine‐aniline) copolymer

Poly(o‐toluidine) (PoT) and poly(o‐toluidine co aniline) were prepared by using ammonium persulfate initiator, in the presence of 1M HCl. It was dried under different conditions: room temperature drying (48 h), oven drying (at 50°C for 12 h), or vacuum drying (under vacuum, at room temperature for 16 h). The dielectric properties, such as dielectric loss, conductivity, dielectric constant, dielectric heating coefficient, loss tangent, etc., were studied at microwave frequencies. A cavity perturbation technique was used for the study. The dielectric properties were found to be related to the frequency and drying conditions. Also, the copolymer showed better properties compared to PoT alone. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 592–598, 2004     

Synthesis and characterization of poly(o‐ and m‐amino benzyl amine) and the copolymers with aniline. Study with Cu(II)

Poly(o‐amino benzyl amine), poly(m‐amino benzyl amine), and the copolymers with aniline were synthesized in 10^?4M HCl by using ammonium persulfate as oxidizing agent. The copolymers were synthesized at various feed mole fractions of comonomer diamine and characterized by elemental analysis, FTIR, ¹H‐NMR spectroscopy, and electrical conductivity. The polymerization yield depended on the substituent position in the aromatic ring. Copper ion was incorporated in the polymers and the amount depended on the side groups position in the aromatic ring. The thermal stability increased when copper ions and aniline units were incorporated in the polymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 31–36, 2004     

Synthesis of poly(aniline‐co‐o‐toluidine) coatings and their corrosion‐protection performance on low‐carbon steel

Strongly adherent poly(aniline‐co‐o‐toluidine) coatings were synthesized on low‐carbon‐steel substrates by the electrochemical copolymerization of aniline with o‐toluidine with sodium tartrate as the supporting electrolyte. These coatings were characterized with cyclic voltammetry, ultraviolet–visible absorption spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and scanning electron microscopy. The formation of the copolymer with the mixture of monomers in the aqueous sodium tartrate solution was ascertained by a critical comparison of the results obtained from the polymerizations of the individual monomers, aniline and o‐toluidine. The optical absorption spectrum of the copolymer was drastically different from the spectra of the respective homopolymers, polyaniline and poly(o‐toluidine). The extent of the corrosion protection offered by poly(aniline‐co‐o‐toluidine) coatings to low‐carbon steel was investigated in aqueous 3% NaCl solutions by open‐circuit‐potential measurements and a potentiodynamic polarization technique. The results of the potentiodynamic polarization measurements showed that the poly(aniline‐co‐o‐toluidine) coatings provided more effective corrosion protection to low‐carbon steel than the respective homopolymers. The corrosion rate depended on the feed ratio of o‐toluidine used for the synthesis of the copolymer coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:1868–1878, 2007     

Preparation and characterization of conducting polymer coating on ABS substrate

Conducting polymer coatings on ABS were prepared by dipping them into m‐cresol solutions containing polyaniline (PANI), poly(o‐toluidine) (POT), and poly(o‐anisidine) (PoAN) protonated with dioctyl hydrogen phosphate (DiOHP) in the presence and absence of polystyrene (PS). The surface resistivity of ABS plates coated with DiOHP‐doped PANI in the presence and absence of PS were 5.3 × 10⁷ and 3.0 × 10⁵ Ω, respectively. The ABS plates coated with DiOHP‐doped PoAN and ‐doped POT showed higher resistivities (4.2 × 10⁹ and 2.4 × 10⁷ Ω, respectively) than that with DiOHP‐doped PANI. Although the conductivity of the coated ABS with DiOHP‐doped PANI was less in the presence of PS, the permanency and uniformity of the coating, which are very important for practical use, were much improved. Coatings and the coated ABS were characterized by X‐ray diffraction, TG/MS, SEM, and reduced viscosity measurements. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2661–2669, 2001     

Synthesis and characterization of conducting poly(aniline‐co‐diaminodiphenylsulfone) copolymers

Polyaniline, poly(aniline‐co‐4,4′‐diaminodiphenylsulfone), and poly(4,4′‐diaminodiphenylsulfone) were synthesized by ammonium peroxydisulfate oxidation and characterized by a number of techniques, including infrared spectroscopy, ultraviolet–visible absorption spectroscopy, ¹H‐NMR, thermogravimetric analysis, and differential scanning calorimetry. These copolymers had enhanced solubility in common organic solvents in comparison with polyaniline. The conductivities of the HCl‐doped polymers ranged from 1 S cm^?1 for polyaniline to 10^?8 S cm^?1 for poly(4,4′‐diaminodiphenylsulfone). The copolymer compositions showed that block copolymers of 4,4′‐diaminodiphenylsulfone (r₁ > 1) and aniline (r₂ < 1) formed and that the reactivity of 4,4′‐diaminodiphenylsulfone was greater than that of aniline. The results were explained by the effect of the ? SO₂? group present in the polymer structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2337–2347, 2003