D. N. Sathyanarayana

Water‐soluble, electrically conductive polyaniline (PANI)–poly(vinyl alcohol) (PVA) blends of different compositions (10, 30, 50, and 70 w/w) were synthesized by emulsion and inverted emulsion methods with ammonium persulfate and benzoyl peroxide as the oxidants, respectively, with PANI protonated with sulfosalicylic acid. The absorption, Fourier transform infrared, Fourier transform Raman, NMR, and electron paramagnetic resonance (EPR) spectroscopic studies suggested chemical interaction between PANI and PVA. The morphology of the blends depended on the method of synthesis as observed from scanning electron microscopy, X‐ray diffraction, and particle size measurements. The blends showed relatively improved mechanical strengths but had lower degradation temperatures than the PANI salt and displayed conductivities as high as 10⁻² to 10⁻¹ S/cm. The blends synthesized by the inverse emulsion method had smaller particle sizes, higher crystallinities, and better mechanical properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 583–590, 2005

Copolymers of aniline and o‐/m‐aminoacetophenone of different compositions were synthesized by oxidative chemical copolymerization. Two different methods were employed, emulsion and inverse emulsion, with different oxidants, ammonium persulphate and benzoyl peroxide, to study the effect of synthesis conditions on the yield, solubility and conductivity of the copolymers. The copolymer compositions were determined using proton NMR spectroscopy. The reactivity ratios determined by the Finemann–Ross method indicate lower reactivity for m‐aminoacetophenone relative to aniline in the emulsion method, while the reverse holds true in the inverse emulsion method. Copolymers formed by the former pathway are random type as determined by the Finemann–Ross method. The copolymers have crystalline/amorphous morphologies and good conductivity. They exhibit enhanced solubility compared with polyaniline. Copyright © 2005 Society of Chemical Industry

Copolymers of aniline and toluidine were synthesized by oxidative chemical polymerization using different ratios of the monomers in the feed, and characterized by a number of techniques including UV–visible, IR, Raman, ¹H NMR and EPR spectroscopies, as well as by thermogravimetric analysis and conductivity measurements. The properties of the copolymers are influenced by the amount of toluidine in the copolymer. Poly(o‐toluidine) and poly(m‐toluidine) are noticeably different in their solubility and conductivity. The copolymers show better solubilities than polyaniline but have lower conductivities. Differences in the properties of the salt and base forms of the copolymers are pointed out. Copyright © 2003 Society of Chemical Industry

This article describes the results of the preparation and characterization of self‐doped conducting copolymers of aniline and toluidine with m‐aminobenzene sulfonic acid. The copolymers have an intrinsic acid group that is capable of doping polyaniline. Spectroscopic, morphological, and electrical conductivity studies have provided insight into the structural and electronic properties of the copolymers. The differences in the properties of polyaniline and polytoluidine due to the sulfonic acid ring substituent on the phenyl ring are discussed. The scanning electron micrographs of the copolymers reveal regions of sharp‐edged, needle‐shaped structures, whereas the X‐ray diffraction patterns show that the copolymers are relatively more crystalline in nature. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4065–4076, 2002

An inverted emulsion method for the synthesis of electrically conductive polyaniline–polystyrene blends of different compositions (10, 30, 50, 70, and 85%, wt/wt) is described. Polymerization of aniline is carried out in chloroform in the dispersed phase by using benzoyl peroxide as a novel oxidant and sulfosalicylic acid as the dopant. The blends synthesized with benzoyl peroxide as the oxidant are of high purity and the excess benzoyl peroxide is readily removed with acetone, which is used to break the emulsion and precipitate the polymer. The absorption spectra, FTIR, FT Raman, and electron paramagnetic resonance spectroscopy confirm the presence of polyaniline in the salt form and polystyrene in the blend. The thermal stability of polyaniline salt decreases with an increase in polystyrene content in the blend. The SEM studies show that the particles of polyaniline–sulfosalicylic acid are dispersed on the polystyrene surface. The blends of polyaniline–polystyrene prepared by the present method were found to display conductivities as high as 0.5–0.1 S cm⁻¹. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1163–1171, 2002