Synthesis and electrochemical properties of poly(2,3‐dimethylaniline)/polyaniline composites

In this study, poly(2,3‐dimethylaniline)/polyaniline (P(2,3‐DMA)/PANI) composite was prepared by in situ polymerization of aniline on the surface of P(2,3‐DMA) particles in hydrochloric acid solution. Fourier transform infrared spectra and X‐ray diffraction results of the composites indicated that P(2,3‐DMA) was successfully modified by PANI. The electrochemical activity and electrical conductivity of the P(2,3‐DMA)/PANI composite were discussed by cyclic voltammetry and standard four‐probe tests, respectively. The results showed that the conductivity of the composite increased with the increasing aniline concentration, which can expand the potential applications of P(2,3‐DMA), such as use in anti‐static coatings or electronic devices. The P(2,3‐DMA)/PANI composite also showed better solubility and anticorrosive property than PANI. POLYM. COMPOS., 36:1541–1545, 2015. © 2014 Society of Plastics Engineers     

Effect of water on inorganic acids doped polyaniline

Based on gravimetric measurements, the effect of water on thin films of inorganic acids doped polyaniline (PANI) was developed. The starting point was the fact that PANI coating on the electrode of quartz crystal microbalances (QCM) showed significant frequency shifts under exposure to liquid water. The changes in the frequency as a function of treatment time in water were quantitatively measured. These changes suggested that the mass decreases under water exposure were due to dopant ions release. The data have been collected using doped PANI films with HCl, H₂SO₄, and H₃PO₄. For PANI‐HCl upon immersion in water showed rapid mass loss followed by slow kinetically dopant ions release with time. However, PANI‐H₃PO₄ and PANI‐H₂SO₄ showed a slow kinetically release out of the film immediately upon immersion in water. The release process was well described by Fickian diffusion process. The diffusion coefficients (D) were determined and found to be dependent on the acid dopant utilized. They varied within the range of (1.68–14.7) × 10^‐14 cm²/s. This work presented an attempt to find a simple method based on the QCM for investigating the diffusion of dopant ions out of thin PANI films upon immersion in water and determining D. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Stability of polyaniline synthesized by a doping–dedoping–redoping method

Stability, including thermal stability, conductivity stability in air and after thermal treatment (100–200°C), of the polyaniline (PANI) films synthesized by a doping–dedoping–redoping method was investigated. It was found that thermogravimetric analysis (TGA) curves undergo three steps: loss of water or solvent, dedoping and decomposition, and those depend on the counterions. Compared with PANI films doped with camphor sulfonic acid (CSA) in m‐cresol, the thermal stability of the doped PANI films is improved by the new method, and thermal stability in the order of PANI–H₃PO₄ > PANI–p‐TSA > PANI–H₂SO₄ > PANI–HCl, PANI–HClO₄ > PANI–CSA was observed. The conductivity of the doped PANI films at room temperature was reduced after thermal treatment, and it is dependent of the counterions. It was found that the conductivity stability of PANI–p‐TSA and PANI–CSA is the best below 200°C. When the doped PANI films were placed in air, their conductivity decrease slowly with time due to deproton, and also depends on the counterions. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 615–621, 1999     

Anhydrous proton conductivity and chemical oxidation stability of amphoteric N‐methyl‐5‐vinyltetrazole‐based copolymers

Poly(N‐methyl‐5‐vinyltetrazole‐co‐5‐vinyltetrazole) (P(MVT‐VT)) with different N‐methyl‐5‐vinyltetrazole (MVT) contents was synthesized via the method of click chemistry and the methylation thereafter. The chemical structure of the copolymers was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). Compared with that of poly(5‐vinyltetrazole) (PVT), the solubility of P(MVT‐VT) is improved. The chemical oxidation stability of the copolymer increases with increasing substitution value of the methyl group on the tetrazole ring. H₃PO₄ and imidazole (Imi) blended PVT and P(MVT‐VT) composite membranes were prepared. The proton conductivity of P(MVT‐VT)/H₃PO₄ and P(MVT‐VT)/Imi composite membranes decreases with increasing MVT content. After the methylation of the tetrazole ring, the amphoteric properties of P(MVT‐VT) is improved, which means either acid or base blended P(MVT‐VT) can exhibit suitable proton conductivity. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Electrochemical behaviors of polyaniline–poly(styrene‐sulfonic acid) complexes and related films

This research focuses on the syntheses of polyaniline with poly(styrenesulfonic acid) and their electrochemical behavior, including absorbance behavior and electrochemical response time of polyaniline‐poly(styrenesulfonic acid) [PANI–PSSA]. The complexes PANI–PSSA were prepared by electrochemical polymerization of monomer (aniline) with PSSA, using indium‐tin oxide (ITO) as working electrode in 1M HCl solution. Polyaniline (PANI), poly(o‐phenetidine)–poly(styrenesulfonic acid) [POP–PSSA], and poly(2‐ethylaniline)–poly(styrenesulfonic acid) [P2E‐PSSA] also were prepared by electrochemical polymerization and to be the reference samples. The products were characterized by IR, VIS, EPR, water solubility, elemental analysis, conductivity, SEM, and TEM. IR spectral studies shows that the structure of PANI–PSSA complexes is similar to that of polyaniline. EPR and visible spectra indicate the formation of polarons. The morphology of the blend were investigated by SEM and TEM, which indicate the conducting component and electrically conductive property of the polymer complexes. Elemental analysis results show that PANI–PSSA has a nitrogen to sulfur ratio (N/S) of 38%, lower than that for POP–PSSA (52%) and P2E–PSSA (41%). Conductivity of the complexes are around 10^?2 S/cm, solubility of PANI–PSSA in water is 3.1 g/L. The UV‐Vis. absorbance spectra of the hybrid organic/inorganic complementary electro‐chromic device (ECD), comprising a polyaniline–poly(styrenesulfonic acid) [PANI–PSSA] complexes and tungsten oxide (WO₃) thin film coupled in combination with a polymer electrolyte poly(2‐acrylamido‐2‐methyl‐propane‐sulfonic acid) [PAMPSA]. PANI–PSSA microstructure surface images have been studied by AFM. By applying a potential of ～3.0 V across the two external ITO contacts, we are able to modulate the light absorption also in the UV‐Vis region (200–900 nm) wavelength region. For example, the absorption changes from 1.20 to 0.6 at 720 nm. The complexes PANI–PSSA, POP–PSSA, and P2E–PSSA were prepared by electrochemical polymerization of monomer (aniline, o‐phenetidine, or 2‐ethylaniline) with poly(styrenesulfonic acid), using ITO as working electrode in 1M HCl solution, respectively. UV‐Vis spectra measurements shows the evidences for the dopped polyaniline system to be a highly electrochemical response time, recorded at the temperature 298 K, and the results were further analyzed on the basis of the color‐ discolor model, which is a typical of protontation systems. Under the reaction time (3 s) and monomer (aniline, o‐phenetidine, 2‐ethylaniline) concentration (0.6M) with PSSA (0.15M), the best electrochemical color and discolor time of the PANI–PSSA is slower than POP–PSSA complexes (125/125 ms; thickness, 3.00 μm) and P2E–PSSA complexes. Under the same thickness (10 μm), the best electrochemical color and discolor time of the PANI–PSSA complexes is 1500/750 ms, that is much slower than P2E–PSSA complexes (750/500 ms) and POP–PSSA complexes (500/250 ms). In film growing rate, the PANI–PSSA complexes (0.54 μm/s) are slower than P2E–PSSA complexes (0.79 μm/s) and POP–PSSA complexes (1.00 μm/s), it can be attributed to the substituted polyaniline that presence of electro‐donating (? OC₂H₅ or ? C₂H₅₎ group present in aniline monomer. The EPR spectra of the samples were recorded both at 298 K and 77 K, and were further analyzed on the basis of the polaron–bipolaron model. The narrower line‐width of the substituted polyaniline complexes arises due to polarons; i.e., it is proposed that charge transport take place through both polarons and bipolarons, compared to their salts can be attributed to the lower degree of structural disorder, the oxygen absorption on the polymeric molecular complexes, and due to presence of electro‐donating (? OC₂H₅ or ? C₂H₅) group present in aniline monomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:4023–4044, 2006     

Preparation of a low‐phosphorous terpolymer as a scale,corrosion inhibitor,and dispersant for ferric oxide

A novel low‐phosphorus terpolymer, used as scale, corrosion inhibitor, and dispersant for iron oxide, was prepared through free‐radical polymerization reaction of acrylic acid (AA), oxalic acid‐allypolyethoxy carboxylate (APEM), and phosphorous acid (H₃PO₃) in water with redox system of hypophosphorous and ammonium persulfate as initiator. Structure of the synthesized AA‐APEM‐H₃PO₃ terpolymer was characterized by Fourier transform infrared spectrometer and ¹H‐NMR. The polymer possesses excellent scale inhibition performance for CaCO₃, outstanding ability to disperse ferric oxide, and good corrosion inhibition properties. The study showed that AA‐APEM‐H₃PO₃ exhibited excellent ability to control calcium carbonate scale, with approximately 90.16% CaCO₃ inhibition at a level of 8 mg/L AA‐APEM‐H₃PO₃. The data of the light transmittance showed that, compared to hydrolyzed polymaleic acid and polyepoxysuccinic acid, AA‐APEM‐H₃PO₃ had superior ability to control iron ions scaling. The light transmittance of the solution was about 24.1% in the presence of the terpolymer when the dosage was 8 mg/L. Moreover, the corrosion inhibition efficiency could reach up to 79.77% at a dosage of 30 mg/L, with ethylene diamine tetra methylene phosphonic acid just 39.62%. Scanning electronic microscopy, transmission electron microscope, and X‐ray powder diffraction analysis were used to investigate the effect of AA‐APEM‐H₃PO₃ on morphology of calcium carbonate scale. The low‐phosphorous terpolymer has also been proven to be effective inhibitor of calcium carbonate even at increasing solution temperature, pH, and Ca²⁺ concentration. The proposed inhibition mechanism suggests the surface complexation and chelation between the functional groups ? P(O) (OH)₂, ? COOH and Ca²⁺, with polyethylene glycol segments increasing its solubility in water. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41447.     

Chemical oxidation stability and anhydrous proton conductivity of polyimides/phosphoric acid/imidazole blends

Polyimides (PIs) based on 3,3′,4,4′‐tetracarboxylicdiphenyl ether dianhydride, 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, 4,4′‐diaminodiphenylsulfone and 4,4′‐methylenedianiline were synthesized. They are easily dissolved in many strong and polar solvents like dimethylformamide, N,N‐dimethylacetamide, 1‐methyl‐2‐pyrrolidinone, and dimethylsulfoxide. A new kind of anhydrous proton conducting system based on PI/H₃PO₄ and PI/H₃PO₄/imidazole (Imi) blends was prepared. The chemical oxidation stability of the composite membranes was studied. The flexible PIs have better chemical oxidation stability. The addition of phosphoric acid can accelerate the degradation process of PIs, while the addition of Imi in PI/H₃PO₄ blends can greatly improve their chemical oxidation stability, which becomes much better than that of pure PIs. The proton conductivity of PI/H₃PO₄ blends is still lower compared with that of polybenzimidazole/H₃PO₄ blends. After the addition of Imi, the anhydrous proton conductivity of PI/H₃PO₄ blends increases significantly with increasing Imi content. Copyright © 2006 Society of Chemical Industry     

Preparation and Characterisation of Proton Exchange Membranes Based on Crosslinked Polybenzimidazole and Phosphoric Acid

Crosslinked polybenzimidazole (PBI) was synthesised via free radical polymerisation between N‐vinylimidazole and vinylbenzyl substituted PBI. The degree of crosslinking increases with increasing content of the crosslinker. The phosphoric acid doping behaviour, mechanical properties, proton conductivity and acid migration stability of crosslinked PBI and linear PBI are discussed. The results show that the acid doping ability decreases with increasing degree of crosslinking of PBI. The introduction of N‐vinylimidazole in PBI is beneficial to its oxidation stability. The mechanical stability of crosslinked PBI/H₃PO₄ membrane is better than that of linear PBI/H₃PO₄ membrane. The proton conductivity of the acid doped membranes can reach ∼10^–4 S cm^–1 for crosslinked PBI/H₃PO₄ composite membranes at 150 °C. The temperature dependence of proton conductivity of the acid doped membranes can be modelled by an Arrhenius relation. The proton conductivity of crosslinked PBI/H₃PO₄ composite membranes is a little lower than that of linear PBI/H₃PO₄ membranes with the same acid content. However, the migration stability of H₃PO₄ in crosslinked PBI/H₃PO₄ membranes is improved compared with that of linear PBI/H₃PO₄ membranes.     

Synthesis,Surface and Antimicrobial Activities of Novel Cationic Gemini Surfactants

A series of novel cationic gemini surfactants [C_nH_2n+1–O–CH₂–CH(OH)–CH₂–N⁺(CH₃)₂–(CH₂)₂]₂·2Br^? [ 3a (n = 12), 3b (n = 14) and 3c (n = 16)] having a 2‐hydroxy‐1,3‐oxypropylene group [?CH₂–CH(OH)–CH₂–O–] in the hydrophobic chain have been synthesized and characterized. Their water solubility, surface activity, foaming properties, and antibacterial activity have been examined. The critical micelle concentration (CMC) values of the novel cationic gemini surfactants are one to two orders of magnitude smaller than those of the corresponding monomeric surfactants. Furthermore, the novel cationic gemini surfactants have better water solubility and surface activity than the comparable [C_nH_2n+1–N⁺(CH₃)₂–(CH₂)₂]₂·2Br^? (n‐4‐n) geminis. The novel cationic gemini surfactants 3a and 3b also exhibit good foaming properties and show good antibacterial and antifungal activities.     

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     

Polyaniline salt containing dual dopants,pyrelenediimide tetracarboxylic acid,and sulfuric acid: Fluorescence and supercapacitor

Storage of energy is considered as the most germane technologies to address the future sustainability. In this study, aniline was chemically oxidized with a controlled concentration of pyrelenediimide tetracarboxylic acid (PDITCA) by ammonium persulfate to polyaniline salt (PANI‐H₂SO₄‐PDITCA), with nanorods morphologies, having a sensibly decent conductivity of 0.8 S cm^?1, wherein H₂SO₄ was generated from ammonium persulfate during polymerization. PANI‐H₂SO₄‐PDITCA salt showed bathochromic fluorescence shift (595 nm) compared to PDITCA (546 nm). The Brunauer–Emmett–Teller surface area of the PANI‐H₂SO₄‐PDITCA‐25 and PANI‐H₂SO₄‐PDITCA‐50 were 18.3 and 21.4 m² g^?1, respectively. Furthermore, its energy storage efficiency was evaluated by supercapacitor cell configuration. The composite PANI‐H₂SO₄‐PDITCA‐50 showed capacitance 460 F g^?1 at 0.3 A g^?1 and large cycle life 85,000 cycles with less retention of 77% to its original capacitance (200 F g^?1) even at a better discharge rate of 3.3 A g^?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45456.     

Preparation of PANI–PVA composite film with good conductivity and strong mechanical property

The polyaniline (PANI)–polyvinyl alcohol (PVA) conductive composite films [doped with hydrochloride (HCl), dodecylbenzene sulphonic acid and amino sulphonic acid (NH₂SO₃H) aqueous solution] were synthesised by ‘in situ’ polymerisation, and their conductivities were compared. Among these composite films, HCl–PANI–PVA composite film possessed the highest conductivity that reached 1360?S·m^??1 [w_(PVA)?=?40%]. Meanwhile, the effects of PVA content, HCl concentration, oxidant ammonium persulphate (APS) dosage, reaction time and film drying temperature on tensile strength of the HCl–PANI–PVA composite films were studied. The tensile strength of the film was improved greatly due to effective mixture of PANI and PVA. When the PVA content was 40%, C_(HCl)?=?1.0?mol·L^??1, reaction time was 4.0?h, n_(APS)/n_(aniline)?=?1.0 and film drying temperature was 80°C, and the tensile strength of the HCl–PANI–PVA composite film reached the maximum of 60.8?MPa. At the same time, the structure of composite materials was characterised and analysed through ultraviolet spectrum and SEM.     

An EPR investigation of conductive polyaniline–poly(methyl methacrylate‐co‐acrylic acid) blends

A conductive blend of polyaniline (PANI) with sodium form poly(methyl methacrylate‐co‐acrylic acid) copolymer (PMMAA) was prepared by in situ dispersion polymerization. The PANI‐PMMAA blends were characterized with UV–vis, FTIR, and electron paramagnetic resonance (EPR) spectra. The effects of PANI and temperature on the electronic properties of the PANI‐PMMAA blends were studied with EPR technique. The PANI and temperature affect the intermolecular interaction between PANI and PMMAA and then determines the EPR parameters (A/B ratio, g factor, T₂, ΔH_pp, N_s, and lineshape). POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

The role of polyaniline salts in the removal of direct blue 78 from aqueous solution: A kinetic study

Three polyaniline salts (PANI–H₂SO₄, PANI–H₃PO₄, and PANI–HNO₃) have been synthesized by chemical oxidative polymerization of aniline. They have been tested as adsorbents for the removal of the textile dye direct blue 78 (DB78) from aqueous solution. The interaction followed pseudo-second-order kinetics whether the rate of interaction was measured from the depletion of dye concentration in solution or the increase in the amount of dye adsorbed on the PANI surface. The removal rate was a function of the activity of the polymer as well as the reaction parameters of the polymer/dye system. The activity of the PANI depended on the polymerization conditions. These conditions involve the concentration of aniline, ammonium peroxydisulfate as oxidant, and sodium dodecylsulfate (SDS), the type of dopant acid (H₂SO₄, H₃PO₄, HNO₃), and the polymerization time. Higher removal rate was observed at oxidant/aniline mole ratio equals 1. The rate of removal was in the order PANI–H₃PO₄ > PANI–H₂SO₄ > PANI–HNO₃. The rate decreased with increasing the concentration of DB78 and pH. It increased with increasing the load of PANI. Pseudo-second-order kinetics, external surface adsorption, and intraparticle diffusion models were concurrently operating in the removal of DB78 with PANI.     

Electrical resistivity and magnetoresistivity of protonic acid (h2SO4 and HCl)‐doped polyaniline at low temperature

Electrical‐transport properties of protonic acid (H₂SO₄ and HCl)‐doped polyaniline (PANI) in an aqueous ethanol medium were investigated in the temperature range 1.8 K ≤ T ≤ 300 K and in a magnetic field up to 8 T. The room‐temperature resistivity of HCl‐doped PANI is larger than that of H₂SO₄‐doped PANI. The resistivity ratios ρ_r = ρ(1.8 K)/ρ(300 K) of the samples are high. The samples in the insulating region show a crossover from a Mott to an Efros–Shklovskii variable range hopping conduction at T = 9.8 K for H₂SO₄‐doped PANI and 8.5 K for HCl‐doped PANI. The magnetoresistivity of these samples is also explained by the variable range hopping theory. The different physical parameters were calculated from the experimental data. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1480–1486, 2000     

Producing Fatty Acid Methyl Esters from Free Fatty Acids with Ionic Liquids as Catalyst

Three Brønsted acidic imidazole dicationic ionic liquids (ILs) with different length of alkyl chains, [C_n(Mim)₂][HSO₄]₂ (n = 3, 6, 12), were prepared and used as catalyst for the esterification reaction of free fatty acids and methanol. Taking oleic acid as model acid, the catalytic performances of the synthesized ILs for the esterification were evaluated. The main physicochemical properties of the ILs, thermal stability, acidity, solubility in common solvents, and causticity on Austenitic stainless steel 316, were examined. [C₃(Mim)₂][HSO₄]₂ demonstrated the highest catalytic activity and enabled to assess the preliminary optimum esterification condition of oleic acid and methanol. Under optimized reaction conditions, the yield of oleic acid methyl ester was up to 95 %. The ILs have great potential as catalysts for producing fatty acid methyl esters from long‐chain free fatty acids.     

Enhanced conductivity of polyaniline in the presence of nonionic amphiphilic polymers and their diverse morphologies

Poly(ethylene oxide) (PEO) and its copolymers have excellent affinity for protons and contribute to proton transfer. In the present study, PEO and its copolymers, poly[(ethylene oxide)₂₀‐(propylene oxide)₇₀‐(ethylene oxide)₂₀] (EO₂₀PO₇₀EO₂₀, P123) and poly[(ethylene oxide)₁₀₆‐(propylene oxide)₇₀‐(ethylene oxide)₁₀₆] (EO₁₀₆PO₇₀EO₁₀₆, F127), have been found to significantly enhance the conductivity of polyaniline (PANI). After introducing these polymers, the conductivity of PANI is markedly promoted more than two orders of magnitude compared to that of PANI without additives, from 5.2 to 667 S/m. The molecular weight of PEO affects the conductivity of PANI/PEO. The mechanism by which these amphiphilic polymers are beneficial to the conductivity of PANI is studied experimentally and theoretically. The PANI/P123 prepared in the presence of PEO block copolymer shows gradually varying morphologies containing leaflike sheets, rodlike particles, and uniform chestnutlike sphere particles. This is similar to the morphology change of micelles with surfactant concentration. PEO, P123, and F127 are further found to have a positive effect on PANI as a material for sensors or supercapacitors, since high specific capacity and fast response rate are desired qualities in sensors and supercapacitors. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45547.     

Role of dual dopants in highly ordered crystalline polyaniline nanospheres: Electrode materials in supercapacitors

Aniline is oxidized by ammonium persulfate oxidant with a weak organic acid, 1,3‐(6,7)‐napthalene trisulfonic acid (NTSA), via an aqueous polymerization pathway to polyaniline (PANI) salt. The effects of the sodium lauryl sulfate surfactant, mineral acid [sulfuric acid (H₂SO₄)], and a combination of surfactant with mineral acid in the aniline polymerization reaction are also carried. These salts were designated as PANI–NTSA–dodecyl hydrogen sulfate (DHS), PANI–NTSA–H₂SO₄, and PANI–NTSA–DHS–H₂SO₄, respectively. Interestingly, PANI–NTSA–DHS showed a highly ordered crystalline sample with a nanosphere morphology. These PANIs were used as electrode materials in supercapacitor applications. Among the four salts, the PANI–NTSA–DHS–H₂SO₄ material showed higher values of specific capacitance (520 F/g), energy (26 W h/kg), and power densities (200 W/kg) at 0.3 A/g. Moreover, 77% of the original capacitance was retained after 2000 galvanostatic charge–discharge cycles with a Coulombic efficiency of 98–100%. PANI–NTSA–DHS–H₂SO₄ was obtained in excellent yield with an excellent conductivity (6.8 S/cm) and a thermal stability up to 235°C. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42510.     

Microstructure and properties of novel fluorescent pyrene functionalized PANI/P(VDF‐HFP) blend

We herein report the preparation and properties of the first polymer blend using pyrene functionalized polyaniline (pf‐PANI). The pf‐PANI has been synthesized and its blend has been prepared with the copolymer of vinylidene fluoride and hexafluoropropylene P(VDF‐HFP). The FTIR results reveal intermolecular interaction between the polar amide group of pf‐PANI and the polarized CH₂ group of P(VDF‐HFP). The crystalline phase of PVDF of the copolymer revealed a transformation from α to β crystalline form after blending with pf‐PANI, as found from FTIR and XRD measurements. The calorimetric measurements together with DMA results revealed the blend is partially miscible. The SEM measurements showed that the pf‐PANI has been dispersed uniformly in the P(VDF‐HFP) matrix. The solution photoluminescence spectrum of the pf‐PANI exhibited emission in the purple–blue region and is slightly red shifted for the blend. The possible applications of this flexible fluorescent pf‐PANI/P(VDF‐HFP) has been suggested. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40162.     

Organic coatings containing polyaniline and inorganic pigments as corrosion inhibitors

Polyaniline (PANI) was synthesized by chemical oxidative polymerization in laboratory conditions. The main objective was to study the properties of organic coatings containing PANI and PANI in combination with other anti-corrosive pigments. The adhesion, barrier, and anti-corrosion properties of the coatings containing PANI and selected chemically active pigments were studied as well as the combination of PANI with zinc dust. Epoxy resin of bisphenol type hardened with a polyamine-based curing agent was used as a binder. In order to examine the synergic effect of PANI and anti-corrosion pigment in epoxy coatings, Zn₃(PO₄)₂·2H₂O with an acidic aqueous extract, Ca₃(BO₃)₂ with a basic aqueous extract and SrCrO₄ with a neutral aqueous extract have been tested.