Synthesis, characterization and electrochromic properties of conducting copolymers of 2,3-bis-[(3-thienylcarbonyl)oxy]propyl 3-thiophene carboxylate with thiophene and pyrrole

2,3-bis-[(3-thienylcarbonyl)oxy]propyl 3-thiophene carboxylate (TOPT) was synthesized via the reaction of 3-thionylcarboxylic acid with glycerol, and electrochemically polymerized either with thiophene and pyrrole by using tetrabutylammonium tetrafluoroborate (TBAFB) as the supporting electrolyte in acetonitrile (AN). Characterization of the resulting copolymers was performed via cyclic voltammetry, FTIR, thermal gravimetry analysis (TGA), and scanning electron microscopy (SEM). Electrical conductivities were measured by the four-probe technique. Spectroelectrochemical analysis shows that the copolymer of the monomer with thiophene has an electronic band gap (due to the π-π^∗ transition) of 2.00 eV, with a dark red color in the fully reduced form and a green color in the fully oxidized form. The copolymer exhibited a long-term switching stability up to 1800 double switches.     

Synthesis and characterization of a new soluble conducting polymer and its electrochromic device

A mixture of isomers 2,5-di(4-methyl-thiophen-2-yl)-1-(4-nitrophenyl)-1H-pyrrole, 2-(4-methyl-thiophen-2-yl)-5-(3-methyl-thiophen-2-yl)-1-(4-nitrophenyl)-1H-pyrrole and 2,5-di(3-methyl-thiophen-2-yl)-1-(4-nitrophenyl)-1H-pyrrole (Me-SNS(NO₂)) were synthesized. Resulting monomers were polymerized chemically, producing soluble polymers in common organic solvents. The average molecular weight has been determined by gel permeation chromatography (GPC) as Mn=5.6×10³ for the chemically synthesized polymer. The monomers were also electrochemically polymerized in the presence of LiClO₄, NaClO₄ (1:1) as the supporting electrolyte in acetonitrile solvent. Resulting polymers were characterized via CV, FTIR, NMR, SEM and UV–Vis spectroscopy. Spectroelectrochemistry analysis of polymer revealed Π–Π^* transition below 300 nm, with an electronic band gap of 2.18 ev. Switching ability of the polymer was evaluated by kinetic study measuring percent transmittance (%T) at the maximum contrast point, indicating that poly(Me-SNS(NO₂)) is a suitable material for electrochromic devices.     

Conducting graft copolymers of pyrrole and thiophene with random copolymers of methyl methacrylate and 3-methylthienyl methacrylate

Random copolymers of 3-methyl thienylmethacrylate and methyl methacrylate were synthesized via free radical polymerization. Electro-copolymerizations of random copolymers with thiophene and/or pyrrole were carried out in acetonitrile-tetrabutylammonium tetrafluoroborate (TBAFB), water-p-toluene sulfonic acid (PTSA) solvent-electrolyte couples. Oxidative polymerization of thiophene functionalized random copolymer was also achieved by constant current electrolysis and chemical polymerization. The characterizations were done by conductivity measurements, cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA), scanning electron microscopy (SEM).     

Synthesis of a dipyrromethane functionalized monomer and optoelectrochromic properties of its polymer

A dipyrromethane functionalized monomer; 5-(4-tert-butylphenyl)dipyrromethane (BPDP) was synthesized. The structure of the monomer was characterized by nuclear magnetic resonance (¹H NMR and ¹³C NMR) and Fourier transform infrared (FTIR) spectroscopies. Electrochemical polymerization of BPDP was performed in acetonitrile (AN)/LiClO₄. The resulting conducting polymer was characterized by FTIR spectroscopy and electrical conductivity measurements. Spectroelectrochemical behavior and switching ability of P(BPDP) film were investigated by UV-Vis spectroscopy. P(BPDP) revealed color changes between yellow and blue in the reduced and oxidized states, respectively. In order to investigate electrochromic properties and stability of the P(BPDP) in electrochromic device (ECDs) application, dual type polymer ECD based on P(BPDP) and poly(ethylene dioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis spectroscopy and cyclic voltammetry.     

Synthesis and electropolymerization of 5,12-dihydrothieno[3′,4′:2,3][1,4]dioxocino[6,7-b]quinoxaline and its electrochromic properties

Synthesis of a new thiophene-based monomer; 5,12-dihydrothieno[3′,4′:2,3][1,4]dioxocino[6,7-b]quinoxaline (DDQ), was realized. The chemical structure of the monomer was characterized by ¹H NMR, FTIR and mass spectroscopy techniques. Electrochemical polymerization of DDQ and characterization of the resulting polymer [P(DDQ)] was performed. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. P(DDQ) has a low oxidation potential (0.9 V) and low band gap (1.73 eV) compared to polythiophene. In addition, dual-type polymer electrochromic device (ECD) based on P(DDQ) with poly(3,4-ethylenedioxythiophene) (PEDOT) was constructed. Spectroelectrochemistry, electrochromic switching, stability and open-circuit stability of the device were studied. It was observed that polymer have good switching time, reasonable contrast and optical memory.     

Living Cationic Polymerization of α-Methylstyrene. 2. Synthesis of Block and Random Copolymers with 2-Chloroethyl Vinyl Ether and End-Functionauzed Polymers†

Abstract

Both AB and BA block copolymers of α-methylstyrene (αMeSt) and 2-chloroethyl vinyl ether (CEVE) were synthesized by the sequential living cationic polymerization initiated with the HCl-CEVE adduct (1a)/SnBr₄ system in CH₂Cl₂ at -78°C. αMeSt-CEVE (AB) block copolymers with narrow molecular weight distributions ([Mbar]_w/[Mbar]_n ～ 1.15) were obtained when αMeSt was polymerized first, followed by addition of CEVE to the resulting αMeSt living polymer solution. The reverse order of monomer addition, from CEVE to αMeSt, also led to a BA-type block copolymer. In the polymerization of a mixture of the two monomers, almost random copolymers were obtained. Living polymerizations of αMeSt were also induced with functional initiating systems, HCl-functionalized vinyl ether adducts (1b-1d)/SnBr₄, to give end-function-alized poly(αMeSt)s with a methacrylate, an acetate, or a phthalimide terminal.     

Electrosyntheses and characterization of a fluorescent conducting copolymer of benzanthrone and thiophene

<正>Poly(benzanthrone-co-thiophene),a new conducting copolymer,was successfully prepared by direct anodic oxidation of benzanthrone and thiophene(Th) in a binary solvent system containing boron trifluoride diethyl etherate (BFEE) and acetonitrile(ACN).The as-formed copolymer film electrodeposited with monomer feed ratio of benzanthrone/Th = 1:1 at the applied potential of 1.3 V versus Ag/AgCl exhibited the advantages of both polybenzanthrone and polythiophene,such as active electrochemical behavior,excellent thermal stability,relatively high electrical conductivity and mechanical properties.UV-Vis spectroscopy,~1H-NMR and SEM were used to characterize and investigate the structures and morphologies of the copolymers.Fluorescence spectroscopy studies revealed that the obtained copolymer films show strong emission at about 525 nm.Moreover,the emitting properties of the copolymers could be tuned by changing some parameters during the electropolymerization process,such as monomer feed ratio.     

Synthesis and characterization of ABA-type block copolymer of poly(trimethylene carbonate) with poly(ethylene glycol): Bioerodible copolymer

ABA-type block copolymers of poly(trimethylene carbonate) with poly(ethylene glycol) (M_n 6820), PTMC-b-PEG-b-PTMC, were synthesized by the ring-opening polymerization of 1,3-dioxan-2-one (trimethylene carbonate) in the presence of poly-(ethylene glycol) with stannous octoate catalyst, and the copolymers with various compositions were obtained. The PTMC-b-PEG-b-PTMC copolymers were characterized with Fourier transform infrared and nuclear magnetic resonance spectroscopies. The intrinsic viscosities of resulting copolymers increased with the increase of 1,3-dioxan-2-one content in feed while the molar ratio of monomer over catalyst kept constant. It has been observed that the glass transition temperature (T_g) of the PTMC segments in copolymers, recorded from differential scanning calorimetry, was dependent on the composition of copolymers. The melting temperature (T_m) of PEG blocks in copolymer was lower than that of PEG polymer, and then disappeared as the length of PTMC blocks increased. The results of dynamic contact angle measurement clearly revealed that the hydrophilicity of resulting copolymers increased greatly with the increase of PEG content in copolymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 695–702, 1998     

Enabling new electrochemical methods with redox-active ionic liquids

Redox-active ionic liquids are obtained by tethering an electroactive center to either the cation, the anion, or both ions in an ionic liquid. While such phases were studied back in the 1990s for their particular electrochemical behavior, they are currently under increased scrutiny for applications in electrochemical systems. This contribution identifies the redox-active ionic liquids’ most important aspects to promote their development. This article provides a review of their features and offers several design guidelines. In addition, it offers an overview of the key properties which enhance their suitability as electrolytes in electrochemical systems, with particular attention paid to lithium-ion batteries and electrochromic devices.     

Thermal analysis of a new thiophene derivative and its copolymer

Thermal characteristics of a new thiophene derivative, 2-(thiophen-3-yl-)ethyl octanoate (OTE), its homopolymer (POTE), and copolymer with thiophene P(OTE-co-Th) were investigated via pyrolysis mass spectrometry. Thermal degradation of the copolymer started by lose of side chains and thiophene involving products evolved almost in the same temperature range where PTh degradation was detected, at slightly higher temperatures than PTh backbone decomposed during the pyrolysis of POTE. The extent of doping and network structure decreased in the order POTE<P(OTE-co-Th)<PTh.     

Synthesis and characterization of carbamoylphosphonate monomer and its copolymer with styrene. II

A monomer, diethyl α,α-dimethyl-m-isopropenylbenzyl carbamoylphosphonate, has been prepared by the base-catalyzed reaction of the isocyanate m-TMI (α,α-dimethyl-m-isopropenylbenzylisocyanate) with diethyl phosphite. The structure of the carbamoylphosphonate monomer and its styrene copolymer was confirmed spectroscopically, and the nature of the hydrogen bondings in the  NHC(O)P(O)(OR)₂ unit in the monomer and copolymer is discussed in detail. A bulk polymerization of the carbamoylphosphonate is very slow and tends to yield a crosslinked product, but a solution polymerization produced the soluble copolymers. The T_g(midpoint) of the homo-polymer is low, 67°C, and its capacity to complex UO₂(NO₃)₂ is very high, 28 wt % (19 mol %). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 889–899, 1997     

Electrochemical synthesis and characterization of poly(pyrrole-co-tetrahydrofuran) conducting copolymer

The direct electrochemical copolymerization of pyrrole and tetrahydrofuran in various monomer ratios was carried out by potentiostatic methods in nitromethane solution. The copolymer has been characterized using FT-IR, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetrical analysis (TGA), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and elemental analysis. The results showed that the electrochemical oxidation of pyrrole and tetrahydrofuran comonomers generated true copolymers rather than blends of the two homopolymers. The copolymer showed a better flexibility than pure polypyrrole. The electrical conductivity of the copolymers increases with the amount of polypyrrole in the copolymer between the value of 1.69 S/cm and 0.71 S/cm.     

Synthesis and characterization of a film‐forming,crosslinked, amphiphilic block copolymer of butadiene and acrylamide

An amphiphilic block copolymer of acrylamide and butadiene was synthesized by the polymerization of acrylamide in the presence of the crosslinker N,N′‐methylene bisacrylamide initiated by a hydroxyl‐terminated polybutadiene/V(V) macroredox initiator. The product had good film‐forming ability. It was characterized by IR and NMR spectroscopy, viscosity, swelling, and microhardness measurements, scanning electron micrography, and differential scanning calorimetry. A good film was obtained from the block copolymer with a greater proportion of butadiene; it had greater permeability for nonpolar solvents, and it was poorly permeable to water and other polar solvents. The film swelled in polar and nonpolar solvents and had almost the same capacity for the loading and release of hydrophilic and hydrophobic dyes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3290–3303, 2006     

Electrosynthesis and characterization of poly(hydroxy-methylated-3,4-ethylenedioxythiophene) film in aqueous micellar solution and its biosensing application

A new and efficient synthetic route to hydroxymethylated-3,4-ethylenedioxylthiophene（EDOT-MeOH） was developed by a simple four-step sequence,and its global yield was approximately 41.06%.The poly（hydroxymethylated-3, 4-ethylenedioxylthiophene）（PEDOT-MeOH） film was electrosynthesized in aqueous sodium dodecylsulfate micellar solutions and characterized by different methods.The EDOT-MeOH possessed better water solubility,and lower onset oxidation potential than EDOT.The as-obtained PEDOT-MeOH film displayed good reversible redox activity,stability and capacitance properties in a monomer-free electrolyte,especially the good solubility of PEDOT-MeOH film in strong polar organic solvents such as dimethyl sulfoxide and tetrahydrofuran created a potential application in many different fields. Fluorescent spectra indicated that PEDOT-MeOH was a yellow-green-light-emitter with maximum emission at 568 nm.The as-formed PEDOT-MeOH film had good biocompatibility and was used for fabricating the electrochemical vitamin C biosensor.The proposed biosensor showed a linear range of 3×10^-6 mol/L to 1.2×10^-2 mol/L with the detection limit of 1μmol/L,a sensitivity of 95.6μA（mmol/L）^-1 cm^-2,and a current response time less than 10 s and a fairly good stability (The relative standard deviation was 0.43%for 20 successive assays,the proposed biosensor still retained 93.5%of bioactivity after 15 days storage.This result indicated that the prepared PEDOT-MeOH film as immobilization matrix of biologically-active species could be a promising candidate for the design and application of biosensor.     

Miniemulsion polymerization of styrene with a block copolymer surfactant

A series of miniemulsion systems based on styrene/azobisisobutyronitrile in the presence of poly(methyl methacrylate‐b‐2‐(dimethylamino)ethyl methacrylate) as a surfactant and hexadecane (HD) as a cosurfactant were developed. For comparison, a series of pseudoconventional emulsions also were carried out with the same procedure used for the aforementioned series but without the cosurfactant (HD). Both the droplet size and shelf life were also measured. Experimental results indicate that it is possible to slow the effect of Ostwald ripening and thereby produce a stable miniemulsion with the block copolymer as the surfactant and HD as the cosurfactant. In addition, the extent to which varying the surfactant concentration and copolymer composition could affect both the polymer particle size during the polymerization and the polymerization rate was examined. Variation in the polymer particle sizes during polymerization indicates that droplet and aqueous (micellar or both homogeneous) nucleation occurs in the miniemulsion polymerization. With the same concentration of the surfactant used in the miniemulsion polymerization, the polymerization rates of systems with M₁₂B₃₆ are faster than those of systems with M₁₂B₁₂. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1818–1827, 2000     

Synthesis,structure characterization,and gas sensitive properties of a copolymer of aniline with phenol

A new kind of conductive copolymers of aniline with phenol was designed and synthesized by using oxidation polymerization and the results showed that the apparent inherent conductivities of the copolymers are in the range of 10^?2 to 10^?10 S/cm which covers from conductors to insulators. The results showed that the conductivity of the copolymers strongly depends on synthesis conditions, such as reaction time, molar ratios of oxidizer to monomers and aniline to phenol, concentrations of reactants, and reaction temperature. Compared to the conventional (co)polymers of aniline and its derivatives, the magnitudes of the reversible conductivity changes are very significant, about two orders, and get to the maximum readings in about 5 min when they are exposed to ammonia gas, hydrochloric acid gas, and a various vapors of organic compounds, such as methanol, alcohol, acetone, benzene, toluene, chloroform, carbon tetrachloride, etc. It should be noted that with the introduction of the weak acidic structural units into the polyaniline chains, the copolymers are reversibly responded to both acidic and basic gases promptly. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis of a nanosize copolymer of 3,4‐ethylenedioxythiophene with diclofenac and characterization

Copolymer of 3,4‐ethylenedioxythiophene (EDOT) and diclofenac (DCF) was synthesized by chemical oxidation using FeCl₃ in neutral medium. The copolymer exhibited good solubility in many organic solvents. The UV‐vis spectrum of the copolymer revealed the presence of benzenoid and polaron or bipolaron state. Random distribution of the monomers in the copolymer was proposed based on the reactivity ratios of the monomers determined using Fineman‐Ross and Kelen‐Tudos methods. The rate of the copolymerization depended on the first power of each monomer. The FTIR spectrum showed the presence of hydrogen bonded N‐H, quinone type structure of thiophene ring and C‐Cl bond in the copolymer. Linear variation of anodic peak current at 560 mV in the cyclic voltammogram of copolymer thin film with scan rate indicated the adherence of electroactive copolymer. When the applied potential increased from ?600 to 1000 mV, the color of the copolymer changed from neutral yellow to brown and to violet medium showing multicolor electrochromic behaviour. XRD results revealed crystallite copolymer with size 87 nm. SEM analysis confirmed uniform crystalline nature of the copolymer. The TGA, DTA and DSC studies suggested good thermal stability of the copolymer. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2787–2796, 2007     

Synthesis and Characterization of Conducting Copolymers of Bisphenol A-Diglycidyl Ether with Thiophene Side-Groups and Pyrrole

Copolymers of bisphenol A-diglycidyl ether with thiophene side-groups and pyrrole were synthesized by electrochemical polymerization. Bisphenol A-diglycidyl ether with thiophene side-groups (DGEBATh) was obtained from the reaction between bisphenol A-diglycidyl ether (DGEBA) and thiophene-3-acetic acid. The syntheses of copolymers of DGEBATh and pyrrole were achieved electrochemically using three different supporting electrolytes, p-toluene sulfonic acid (PTSA), sodium dodecyl sulfate (SDS) and tetrabutylammonium tetrafluoroborate (TBAFB). Characterizations of DGEBATh and copolymers were performed by combination of techniques including cyclic voltammetry, scanning electron microscopy, gel permeation chromatography, differential scanning calorimetry, ¹H-NMR and FT-IR. The conductivities were measured by the four-probe technique.     

Ferrocene clicked poly(3,4-ethylenedioxythiophene) conducting polymer: Characterization, electrochemical and electrochromic properties

The “click” chemistry, Cu(I)-catalyzed azide–alkyne cycloaddition reaction, was applied to covalently functionalize the poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer film with an excellent electron transfer mediator (ferrocene). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy were used to characterize the ferrocene-grafted PEDOT conducting polymer film, and it was proved that the grafting procedure via click reaction had a high efficiency. The ferrocene groups covalently grafted in the polymer films turned out to own a relatively fast electron transfer rate and show multi-color states via adjusting applied potential.     

Synthesis of nylon‐6 triblock copolymers with bifunctional polymeric activators

ABA‐type copolymers were synthesized by the anionic polymerization of hexanelactam with the sodium salt of hexanelactam as an initiator and amino‐terminated polytetrahydrofuran telechelic functionalized with diisocyanates. Two types of diisocyanates, hexamethylene diisocyanate (1,6‐diisocyanatohexane) and isophorone diisocyanate (IF; 5‐isocyanato‐1‐isocyanatomethyl‐1,3,3‐trimethylcyclohexane), were used as precursors for polymeric activators (PACs). IF was used for the first time. It was proven that the PACs were incorporated as soft, flexible midblocks in the chains of hard nylon‐6 segments. The polymers were isolated and characterized with various spectroscopic techniques. The effects of the central PAC block (according to the type, molecular weight, and content) and the polymerization conditions on the kinetics, activation energies, molecular weights, and structures of the triblock copolymers were investigated. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4154–4164, 2000