Poly(2‐) and (3‐aminobenzoic acids) and their copolymers with aniline: Synthesis,characterization, and properties

Poly(2‐aminobenzoic acid) and poly(3‐aminobenzoic acid) were synthesized by chemical polymerization of the respective monomers with aqueous 1M hydrochloric acid and 0.49M sodium hydroxide, using ammonium persulfate as an oxidizing agent. In addition, polymerization in an acid medium was carried out in the presence of metal ions, such as Cu(II), Ni(II), and Co(II). Poly(2‐aminobenzoic acid‐co‐aniline) and poly(3‐aminobenzoic acid‐co‐aniline) were synthesized by chemical copolymerization of aniline with 2‐ and 3‐aminobenzoic acids, respectively, in aqueous 1M hydrochloric acid. The copolymers were synthesized at several mole fractions of aniline in the feed and characterized by UV–visible and FTIR spectroscopy, the thermal stability, and the electrical conductivity. Metal ions, such as Cu(II), Ni(II), and Co(II), were incorporated into homo‐ and copolymers by the batch method. The percentage of metal ions in the polymers was higher in the copolymers than in the homopolymers. The thermal stability of the copolymers increased as the feed mole fraction of aniline decreased and varied with the incorporation of metal ions in the polymers. The electrical conductivity of the homo‐ and copolymers was measured, which ranged between 10^?3 and 10^?10 S cm^?1. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2641–2648, 2003     

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 and characterization of proccessible polyaniline derivatives for corrosion inhibition

This article reports the synthesis and characterization of copolymers based on aniline and substituted anilines by using dodecylbenzene sulfonic acid as a dopant. The copolymers were soluble in organic solvents, such as methanol, ethanol, isopropanol, N‐methylpyrrolidinone, dimethylsulphoxide, and have conductivity of the order of 1.5 to 10^?7 S/cm depending upon the monomer ratios and extent of dopant used. The effect of substituents like 2‐methyl, 2‐ethyl, and 2‐isopropyl groups on the electrochemical, conductivity, thermal stability, solubilization, and spectroscopic behavior of the copolymers has been evaluated. The composition of the copolymers was determined by ¹H‐NMR spectroscopy. Corrosion inhibition behavior of the copolymers in 1.0N HCl has been evaluated using linear polarization resistance method and Tafel extrapolation method. The corrosion efficiency depends upon the copolymer composition and it increased with increasing amount of 2‐alkyl aniline in the feed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A new approach to soluble polyaniline and its copolymers with toluidines

Homopolymers of aniline, toluidines and their copolymers were synthesized by chemical oxidative polymerization using different ratios of monomers in the feed in H₂SO₄ medium. The synthesized polymers were characterized by employing Fourier transform infrared, UV‐visible, proton nuclear magnetic resonance, X‐ray diffraction techniques for understanding the details of the structure of the synthesized polymers. Morphological, thermal, and electrical conductivity of the as synthesized polymers were also studied by employing scanning electron microscopy, thermogravimetric analysis, and dc electrical conductivity, respectively. From the SEM images rod shaped nanoparticles were observed in PANI and spherical shaped nanoparticles were observed for copolymers. A three‐step thermal degradation was observed for all the polymers. The electrical conductivities of the copolymers were less compared with PANI, and at higher temperature the conductivities of all the polymers were more or less same. It was observed that yield and intrinsic viscosity of copolymers are not regularly dependant on monomer concentration in the feed. The copolymers show better solubility but lower conductivity than PANI. Properties of homopolymers and copolymers are also pointed out. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and Characterization of Poly[bis(3-aminophenyl) diselenide] and Poly[bis(3-aminophenyl) diselenide-co-aniline]

Summary Bis(m-aminophenyl)diselenide was synthesized by diazotation of m-nitroaniline followed by incorporation of potassium selenium cyanate, and the reduction of the nitro groups by addition of tin and concentrated HCl. This dihydrochloride monomer was polymerised using ammonium persulphate in 0.25 M HCl as oxidizing agent. Copolymers of aniline with bis(m-aminophenyl)diselenide were prepared by oxidation of diselenide and aniline mixtures, at several mole ratios of aniline in the feed (f₁), with the same oxidizing agent. In the all the range of polymers analysed there are more diselenide comonomer units than aniline units. The polymer and copolymers were characterized by FTIR, elemental analysis, thermal stability and electrical conductivity, showing a high thermal stability, with a weight loss of 10% at 400 °C and there is an important effect of groups diselenide on the electrical properties, because conductivities are highly modified when the substitution is in m-position in the aniline ring. Therefore, it is necessary to add a high mole ratio of aniline in the feed to obtain copolymers with conductivities within the semi-conduction range.     

Synthesis and properties of novel conducting polyaniline copolymers

A novel copolymer based on aniline and N‐β‐cyanoethylaniline was chemically prepared and characterized by a number of techniques including UV–vis, FTIR, ESR, XRD, and TGA. According to the systematic studies on the physical properties, it was found that the copolymers had excellent solubility in common organic solvents especially in DMF and pyridine, while the conductivity and yield decreased as the content of cyanoethyl group increased in the system. Moreover, an increase in the feed ratio of N‐β‐cyanoethylaniline induced a blue‐shift of the absorption bands in the UV–vis and IR region and significant line broadening of ESR signals together with a reduction in spin density. The XRD patterns of the copolymers lost the characteristic diffraction peaks of emeraldine salt as the ratio of cyanoethyl group increased. The thermal stability of the copolymer was increased with increasing the feed molar ratio of N‐β‐cyanoethylaniline. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 140–147, 2007     

Copolymers of aniline with o‐ and m‐toluidine: synthesis and characterization

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     

Doped polyaniline/multiwalled carbon nanotube composites: Preparation and characterization

Polyaniline (PANI)/multiwalled carbon nanotube (MWNT) composites with a uniform tubular structure were prepared from in situ polymerization by dissolving amino‐functionalized MWNT (a‐MWNT) in aniline monomer. For this the oxidized multiwalled nanotube was functionalized with ethylenediamine, which provided ethylenediamine functional group on the MWNT surface confirmed by Fourier‐transform infrared spectra (FT‐IR). The a‐MWNT was dissolved in aniline monomer, and the in situ polymerization of aniline in the presence of these well dispersed nanotubes yielded a novel tubular composite of carbon nanotube having an ordered uniform encapsulation of doped polyaniline. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the nanotubes were coated with a PANI layer. The thermal stability and electrical conductivity of the PANI /MWNTs composites were characterized by thermogravimetric analysis (TGA) and conventional four‐probe method respectively. Compared with pure PANI, the electrical conductivity and the decomposition temperature of the MWNTs/PANI composites increased with the enhancement of MWNT content in PANI matrix. POLYM. COMPOS., 34:1119–1125, 2013. © 2013 Society of Plastics Engineers     

Dielectric properties of lithium‐perchlorate‐filled acrylonitrile–hexyl methacrylate copolymer films

A series of poly(acrylonitrile‐co‐hexyl methacrylate), PAN‐co‐PHMA, copolymers with various hexyl methacrylate (HMA) contents were synthesized by emulsion technique. The incorporation of HMA units into the copolymers was confirmed by Fourier transform infrared and proton nuclear magnetic resonance (¹H‐NMR) spectroscopy. Glass transition temperatures (T _g) and thermal decomposition temperatures of copolymers were determined by differential scanning calorimetry and thermogravimetric analysis. The T _g of copolymers were lowered monotonically by increasing HMA content, while thermal stabilities of copolymers were enhanced. The frequency dependence of dielectric properties of three different amounts of LiClO₄ salt doped copolymer films was investigated. The influence of molar fraction of HMA on dielectric constant and ac‐conductivity of copolymer films was examined. Samples with higher HMA contents showed better stability and conductivity, as a result of increase in free volume and the mobility of the dipoles. The ac conductivity of copolymers was also improved by increasing LiClO₄ salt which was due to the existence of more charge carriers. PAN(88)‐co‐PHMA(12) copolymer with 1.5 mol% of lithium salt exhibited ionic conductivity of the 7.8 × 10⁻⁴ S/cm at 298 K. POLYM. COMPOS., 38:1792–1799, 2017. © 2015 Society of Plastics Engineers     

Synthesis and thermotropic liquid‐crystalline behavior of novel main‐chain poly(aryl ether ketones)

Novel aromatic poly(ether ketones) containing bulky lateral groups were synthesized via nucleophilic substitution reactions of 4,4′‐biphenol and (4‐chloro‐3‐trifluoromethyl)phenylhydroquinone (CF‐PH) with 1,4‐bis(p‐fluorobenzoyl)benzene. The copolymers were characterized by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction, and polarized light microscopy observation. Thermotropic liquid‐crystalline behavior was observed in the copolymers containing 40, 50, 60, and 70 mol % CF‐PH. The crystalline–liquid‐crystalline transition [melting temperature (T_m)] and the liquid‐crystalline–isotropic phase transition appeared in the DSC thermograms, whereas the biphenol‐based homopolymer had only a melting transition. The novel poly(aryl ether ketones) had glass‐transition temperatures that ranged from 143 to 151°C and lower T_m's that ranged from 279 to 291°C, due to the copolymerization. The polymers showed high thermal stability, and some exhibited a large range in mesophase stability. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1347–1350, 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     

The effect of chemical heterogeneity on the properties of statistical copolymers: the conductivity of poly(aniline‐co‐2‐bromoaniline)

Chemical heterogeneity can influence the properties of statistical copolymers. It is shown that any integral property of a copolymer will depend on the chemical heterogeneity if such a property is a non‐linear function of copolymer composition. This is illustrated by means of the conductivity of copolymers of aniline and 2‐bromoaniline. The monomer reactivity ratios of this monomer pair are r_A (aniline) = 0.94 and r_B (2‐bromoaniline) = 0.31. The dependence of conductivity on the copolymer composition is non‐linear. Consequently, the conductivity depends on the compositional distribution, ie on the extent of chemical heterogeneity. Heterogeneous high‐conversion copolymers have lower conductivity than corresponding relatively homogeneous low‐conversion copolymers. The change in the average copolymer composition with increasing conversion is demonstrated for a copolymerization mixture containing 30 mol% aniline. The conductivity decreases at the same time as the chemical heterogeneity of the copolymer develops. The change in the average copolymer composition alone cannot explain the observed conductivity decrease. The conductivity is dependent not only on average composition but also on the chemical composition distribution. Copyright © 2004 Society of Chemical Industry     

Oxygen barrier properties of PET copolymers containing bis(2‐hydroxyethyl)hydroquinones

A series of poly[ethylene‐co‐bis(2‐ethoxy)hydroquinone terephthalate], PET‐co‐BEHQ copolymers were prepared by polymerization of various substituted bis(2‐hydroxyethyl)hydroquinones (BEHQs), dimethyl terephthalate (DMT), and ethylene glycol (EG). In addition to copolymers containing 6–16.5 mol % BEHQ, the homopolymer of BEHQ with dimethyl terephthalate, p(BEHQ‐T), was also prepared. The thermal and barrier properties of amorphous materials were studied. As the amount of comonomer was increased, the T_g and T_m of the materials decreased relative to those of PET. Oxygen permeability also decreased with increasing comonomer content. This improvement in barrier‐to‐oxygen permeability was primarily due to a decrease in solubility of oxygen in the polymer. All of the copolymers tested displayed similar oxygen diffusion coefficients. The decrease in solubility correlates with the decrease in T_g. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 934–942, 2003     

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     

Controllable synthesis and characterization of poly(aniline‐co‐pyrrole) using anionic spherical polyelectrolyte brushes as dopant and template

A poly(aniline‐co‐pyrrole), using anionic spherical polyelectrolyte brushes (ASPB) as dopant and template, was synthesized by chemical oxidation polymerization. The composites were characterized by scanning electron microscopy (SEM), Fourier‐transform infrared spectrometry (FTIR), X‐ray diffraction (XRD), and electrical studies. The SEM images confirmed that the composites had a spherical‐like structure, with a size of ca. 170 nm. The FTIR spectra showed the intermolecular interaction between poly(aniline‐co‐pyrrole) and ASPB. The XRD analysis revealed that the interplanar distance of the copolymers increased from 0.373 nm to 0.391 nm. The electrical conductivity of the poly(aniline‐co‐pyrrole)/ASPB nanocomposites at room temperature was 8.3 S cm⁻¹, higher than that of the conducting copolymers (2.1 S cm⁻¹). These conductive nanocomposites have nanoparticle size, controllable morphology, and the potential for application in inkjet electronic printing. POLYM. COMPOS., 35:1858–1863, 2014. © 2014 Society of Plastics Engineers     

Synthesis and electrical properties of copolymers of o‐phenylenediamine with aniline, 3,4‐ethylenedioxythiophene and 2,3,5,6‐tetrafluoroaniline

Copolymers (P(PDA/Ar)) of o‐phenylenediamine with aniline (Ar = ANi), 3,4‐ethylenedioxythiophene (Ar = EDOT) and 2,3,5,6‐tetrafluoroaniline (Ar = TFANi) were synthesized via polycondensation initiated by ammonium persulfate. The NH₂ group content in the copolymers was determined by analyzing the ¹H NMR spectra of the N‐acetylated copolymers. Copolymers crosslinked by viologen (1,1'‐disubstituted 4,4'‐bipyridinium dichloride) were obtained by reaction involving the reactive NH₂ groups in the copolymers. The absorption wavelengths of solutions of the copolymers and the electrochemical oxidation and reduction potentials of cast films of the copolymers were affected by the electrical properties of the Ar unit. © 2016 Society of Chemical Industry     

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     

Synthesis and characterization of ABA‐type block copolymers of trimethylene carbonate and ϵ‐caprolactone

This paper describes the synthesis of a series of ABA‐type triblock copolymers of trimethylene carbonate and ?‐caprolactone with various molar ratios and analyses the thermal and mechanical properties of the resulting copolymers. The structures of the triblock copolymers were characterized by ¹H and ¹³C nuclear magnetic resonance spectroscopy, FT‐IR spectroscopy and gel permeation chromatography. Results obtained from the various characterization methods proves the successful synthesis of block copolymers of trimethylene carbonate and ?‐caprolactone. The thermal properties of the block copolymers were investigated by differential scanning calorimetry. The T_m and ΔH_m values of the copolymers decrease with increasing content of trimethylene carbonate units. Two T_gs were found in the copolymers. Furthermore, both of the T_g values increased with increasing content of trimethylene carbonate units. The mechanical properties of the resulting copolymers were studied by using a tensile tester. The results indicated that the mechanical properties of the block copolymers are related to the molar ratio of trimethylene carbonate and ?‐caprolactone in the copolymers, as well as the molecular weights of the resulting copolymers. The block copolymer with a molar composition of 50/50 possessed the highest tensile stress at maximum and modulus of elasticity. Block copolymers possessing different properties could be obtained by adjusting the copolymer compositions. Copyright © 2004 Society of Chemical Industry     

Synthesis and hydrophilicity of poly(butylene 2,6‐naphthalate)/poly(ethylene glycol) copolymers

Poly(butylene 2,6‐naphthalate) (PBN)/poly(ethylene glycol) (PEG) copolymers were synthesized by the two‐step melt copolymerization process of dimethyl‐2,6‐naphthalenedicarboxylate (2,6‐NDC) with 1,4‐butanediol (BD) and PEG. The copolymers produced had different PEG molecular weights and contents. The structures, thermal properties, and hydrophilicities of these copolymers were studied by ¹H NMR, DSC, TGA, and by contact angle and moisture content measurements. In particular, the intrinsic viscosities of PBN/PEG copolymers increased with increasing PEG molecular weights, but the melting temperatures (T_m)_, the cold crystallization temperatures (T_cc)_, and the heat of fusion (ΔH_f) values of PBN/PEG copolymers decreased on increasing PEG contents or molecular weights. The thermal stabilities of the copolymers were unaffected by PEG content or molecular weight. Hydrophilicities as determined by contact angle and moisture content measurements were found to be significantly increased on increasing PEG contents and molecular weights. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2677–2683, 2006     

Novel electrically conductive and ferromagnetic composites of poly(aniline‐co‐aminonaphthalenesulfonic acid) with iron oxide nanoparticles: Synthesis and characterization

Nanocomposites of iron oxide (Fe₃O₄) with a sulfonated polyaniline, poly(aniline‐co‐aminonaphthalenesulfonic acid) [SPAN(ANSA)], were synthesized through chemical oxidative copolymerization of aniline and 5‐amino‐2‐naphthalenesulfonic acid/1‐amino‐5‐naphthalenesulfonic acid in the presence of Fe₃O₄ nanoparticles. The nanocomposites [Fe₃O₄/SPAN(ANSA)‐NCs] were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, elemental analysis, UV–visible spectroscopy, thermogravimetric analysis (TGA), superconductor quantum interference device (SQUID), and electrical conductivity measurements. The TEM images reveal that nanocrystalline Fe₃O₄ particles were homogeneously incorporated within the polymer matrix with the sizes in the range of 10–15 nm. XRD pattern reveals that pure Fe₃O₄ particles are having spinel structure, and nanocomposites are more crystalline in comparison to pristine polymers. Differential thermogravimetric (DTG) curves obtained through TGA informs that polymer chains in the composites have better thermal stability than that of the pristine copolymers. FTIR spectra provide information on the structure of the composites. The conductivity of the nanocomposites (～ 0.5 S cm^?1) is higher than that of pristine PANI (～ 10^?3 S cm^?1). The charge transport behavior of the composites is explained through temperature difference of conductivity. The temperature dependence of conductivity fits with the quasi‐1D variable range hopping (quasi‐1D VRH) model. SQUID analysis reveals that the composites show ferromagnetic behavior at room temperature. The maximum saturation magnetization of the composite is 9.7 emu g^?1. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007