Electrodeposition of free‐standing poly(o‐dihydroxybenzene‐co‐3‐methylthiophene) films with tunable fluorescence properties

Electrochemical copolymerization of o‐dihydroxybenzene (oDHB) and 3‐methylthiophene (3MeT) was successfully achieved in boron trifluoride diethyl etherate by direct anodic oxidation of the monomer mixtures, although the oxidation potentials of oDHB and 3MeT were quite different. The influence of the applied polymerization potential on the synthesis of the copolymers was investigated. The higher applied potential favored the incorporation of 3MeT units into the copolymers. The structure and properties of the copolymers were investigated with UV‐vis spectroscopy, fluorescence spectroscopy, FTIR spectroscopy, and thermal analysis. The novel copolymers had many advantages, including good redox activity, good thermal stability, and high electrical conductivity. Additionally, the copolymers fluorescence properties that were tunable through changes in the feed ratio of the monomer mixtures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrochemical synthesis and properties of poly(3‐methylthiophene): Novel synthesis of poly(3‐methylthiophene) with pentachlorostannate and hexachloroantimonate

Poly(3‐methylthiophene) (P3‐MeT) doped with different anions were prepared electrochemically in the presence of tetraalkylammonium salts. The new poly(3‐methylthiophene) SnCl and SbCl (P3‐MeT SnCl₅ and P3‐MeT SbCl₆) were prepared electrochemically using tetra‐n‐butylammonium pentachlorostannate and tetra‐n‐butylammonium hexachloroantimonate as the supporting electrolytes. The effect of current density, salt concentration, reaction temperature, and the nature of solvents on the polymer yield and polymer conductivities have been investigated. Cyclic voltammetry of poly(3‐methylthiophene) has been examined at platinum electrode in 1,2‐dichloroethane medium containing n‐Bu₄NSnCl₅, Bu₄NSbCl₆, and Bu₄NClO₄ as the supporting electrolytes in the range of −1.0 to 1.7 V versus SCE in the presence and absence of 3‐methylthiophene. Electrical conductivity, magnetic susceptibility measurements, and structural determination by elemental analysis and infrared studies were also made. Scanning electron microscopy revealed a globular, branched, fibrous and a spongy, fibrous morphology of poly(3‐methylthiophene) SnCl, ClO, and SbCl, respectively. The thermal analysis of the polymers was also investigated. Possible causes for the observed lower conductivity of these polymers have also been discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 91–102, 1999     

A theoretical investigation on the properties of the new poly(N‐vinylcarbazole)‐3‐methylthiophene (PVK‐3MeT) synthesized graft copolymer

In this article, we present quantum chemical calculations, based on density functional theory (DFT), performed to investigate the geometries and the opto‐electronic properties of a new synthesized graft copolymer based on poly(N‐vinylcarbazole) (PVK) and poly(3‐methylthiophene) (PMeT) named PVK‐3MeT. First, we have theoretically computed and compared the structural, optical, and vibrational parameters of both neutral and doped states. In addition, the excited state was theoretically obtained by the ab initio RCIS/STO‐3G method. To assign the absorption and emission peaks observed experimentally, we computed the energies of the lowest singlet excited state with the time‐dependent density functional theory (TD‐DFT) method. Electronic parameters such as the HOMO‐LUMO band gap, the ionization potential (IP), and electron affinity (EA) are extracted. Calculations show that the PVK‐3MeT copolymer is nonplanar in its ground neutral state. Meanwhile, upon doping or photoexcitation, an enhancement of the planarity is observed, resulting on a decrease of the inter‐ring torsion angle between 3‐methylthiophene units. Such modifications in the geometric parameters induce a dramatic change on the HOMO and LUMO orbitals in the doped or excited states. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Electrodeposition of High-quality Polycarbazole Films in Composite Electrolytes of Boron Trifluoride Diethyl Etherate and Ethyl Ether

High-quality polycarbazole (PCZ) films were synthesized electrochemically by direct oxidation of carbazole in boron trifluoride diethyl etherate (BFEE) containing vol. 20% ethyl ether (EE). The oxidation potential of carbazole in this medium was measured to be only 0.90 V vs. SCE, which was lower than that determined in acetonitrile containing 0.1 mol l⁻¹ Bu₄NBF₄ (1.35 V vs. SCE). PCZ films obtained from this medium showed better electrochemical behavior, better thermal stability with conductivity of 7.5 × 10⁻³ S cm⁻¹ being one order of magnitude higher than those reported previously, indicating that BFEE/EE was a better medium than acetonitrile for the electrosyntheses of PCZ films. As-formed PCZ films can be partly dissolved in acetone, acetonitrile and tetrahydrofuran. Spectral analysis provided evidence for the existence of the conjugated structure of the PCZ chain. Fluorescent spectra indicate that electrosynthesized PCZ is an ideal blue light emitter.     

ABA triblock copolymers from poly(p‐dioxanone) and poly(ethylene glycol)

Poly(p‐dioxanone)–poly(ethylene glycol)–poly(p‐dioxanone) ABA triblock copolymers (PEDO) were synthesized by ring‐opening polymerization from p‐dioxanone using poly(ethylene glycol) (PEG) with different molecular weights as macroinitiators in N₂ atmosphere. The copolymer was characterized by ¹H NMR spectroscope. The thermal behavior, crystallization, and thermal stability of these copolymers were investigated by differential scanning calorimetry and thermogravimetric measurements. The water absorption of these copolymers was also measured. The results indicated that the content and length of PEG chain have a greater effect on the properties of copolymers. This kind of biodegradable copolymer will find a potential application in biomedical materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1092–1097, 2006     

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     

Conjugated copolymers of cyanosubstituted poly(p‐phenylene vinylene) with phenylene ethynylene and thienylene vinylene moieties: Synthesis,optical, and electrochemical properties

Three alternating conjugated copolymers of cyanosubstituted poly(p‐phenylene vinylene) (CN–PPV) with phenylene ethynylene and thienylene vinylene moieties, P1, P2, and P3, were synthesized via cross‐coupling polycondensation with Pd(PPh₃)₂Cl₂ as a catalyst. Their structures were confirmed by ¹H‐NMR, IR spectroscopy, elemental analysis, and gel permeation chromatography, and the thermal, photophysical, and electrochemical properties of the copolymers were also investigated. The incorporation of a triple bond into the CN–PPV backbone led to higher reduction potentials, which corresponded to lower lowest unoccupied molecular orbital energy levels. The three copolymers possessed broader absorption spectra, especially copolymer P3 with its polymerization units containing two thiophene rings, which showed the broadest absorption spectrum, from 300 to 710 nm. Their high electron affinities, broad absorptions, and relatively higher oxidation potentials make the copolymers potentially good electron‐acceptor material for use in photovoltaic devices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Flame retardancy of a polycarbonate–polydimethylsiloxane block copolymer: The effect of the dimethylsiloxane block size

This report describes the flame retardancy of a polycarbonate (PC)–polydimethylsiloxane (PDMS) block copolymer with a dimethylsiloxane (DMS) block size of 15–350 units, and the effects of the block size and amount of DMS on the flame retardancy are studied. PC–PDMS block copolymers with DMS units of 40–130 had high limiting oxygen index values with 1.0 wt % PDMS. The PDMS block size influenced the PDMS dispersibility in PC, and a moderate PDMS dispersion (ca. 50 nm) caused high flame retardancy for PC. These PC–PDMS block copolymers could form a lot of fine bubbles in the role of good thermal insulators through the reaction of PC and PDMS in combustion. Furthermore, the silica particles from PDMS remained mostly on the surface of the char, so the amount of char with high oxidation resistance increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 565–575, 2006     

Synthesis and characterization of poly(aryl ether sulfone)s with metallophthalocyanine pendant unit

A series of novel poly(aryl ether sulfone) copolymers containing dicyanophenyl group were prepared by the reaction of bis(4‐chlorophenyl)sulfone with (3,4‐dicyano) phenylhydroquinone and 4,4′‐isopropylidenediphenol. On this basis, a series of poly(aryl ether sulfone)s containing metallophthalocyanine units were synthesized by the reaction of poly(aryl ether sulfone)s containing dicyanophenyl group with excessive amounts of 1,2‐dicyanobenzene and the corresponding metal salt in quinoline. All these copolymers were found to have high glass transition temperature and thermal stability. These copolymers were found to be soluble in common solvents, and capable of forming transparent films by solution casting. The copolymers containing metallophthalocyanine units showed strong optical absorption in the visible region, and exhibited blue photoluminescence in solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3457–3461, 2006     

4‐chloro‐3‐methylphenyl methacrylate copolymers with 2,4‐dichlorophenyl methacrylate: Synthesis,characterization, and antimicrobial activity

4‐Chloro‐3‐methylphenyl methacrylate (CMPM) and 2,4‐dichlorophenyl methacrylate (2,4‐DMA) were synthesized by reacting methacryloyl chloride with 4‐chloro‐3‐methylphenol (CMP) and 2,4‐dichlorophenol (2,4‐DP), respectively. Homo and copolymers of CMPM and 2,4‐DMA were obtained from different monomer feed ratios, using 2,2′‐azobisisobutyronitrile as initiator in toluene at 70°C. IR‐spectroscopy was employed to characterize the resulting homo and copolymers. Copolymer compositions were determined by ultraviolet (UV) spectroscopy. Fineman–Ross method was used to calculate the reactivity ratios of the monomers. Average molecular weight and polydispersity index were obtained by gel permeation chromatography (GPC). Thermogravimetric analyses (TGA) and differential thermal analysis (DTA) of copolymers were carried out under a nitrogen atmosphere. Antimicrobial effects of the homo and copolymers were also investigated for various microorganisms such as bacteria, fungi, and yeast. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:439–448, 2006     

Electrosyntheses and characterizations of a new soluble conducting copolymer of 5-cyanoindole and 3,4-ethylenedioxythiophene

The copolymerization of 5-cyanoindole (CNIn) and 3,4-ethylenedioxythiophene (EDOT) was successfully performed electrochemically in acetonitrile containing tetrabutylammonium tetrafluoroborate by direct oxidation of monomer mixtures. The electrochemical properties of the copolymers were studied by cyclic voltammetry. The influence of applied polymerization potential on the synthesis of copolymer was investigated. This novel copolymer owns the advantages of poly(5-cyanoindole) (PCNIn) and poly(3,4-ethylenedioxythiophene) (PEDOT), i.e., good redox activity, good thermal stability and high conductivity. The copolymer was soluble in dimethyl sulfoxide. The fluorescence spectra indicate that the copolymer is a good blue-light emitter. The structure and morphology of the copolymers were investigated by UV–vis, infrared spectroscopy, ¹H NMR spectra and scanning electron microscopy (SEM), respectively.     

Novel amphiphilic polymer gel electrolytes based on (PEG‐b‐GMA)‐co‐MMA

Amphiphilic conetwork–structured copolymers containing different lengths of ethylene oxide (EO) chains as ionophilic units and methyl methacrylate (MMA) chains as ionophobic units were prepared by free radical copolymerization and characterized by FTIR and thermal analysis. Polymer gel electrolytes based on the copolymers complexed with liquid lithium electrolytes (dimethyl carbonate (DMC) : diethyl carbonate (DEC) : ethylene carbonate (EC) = 1 : 1 : 1 (W/W/W), LiPF₆ 1.0M) were characterized by differential scanning calorimetry and impedance spectroscopy. A maximum ion conductivity of 4.27 × 10^?4 S/cm at 25^oC was found for the polymer electrolyte based on (PEG2000‐b‐GMA)‐co‐MMA with long EO groups. Moreover, the effect of temperature on conductivity of the amphiphilic polymer electrolytes obeys the Arrhenius equation. The good room temperature conductivity of the polymer electrolytes is proposed to relate to the enhancement in the amorphous domain of the copolymers due to their amphiphilic conetwork structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Electrochemical copolymerization of 3,4-ethylenedioxythiophene and 5-methylindole and characterizations of the copolymers

Electrocopolymerization of 3,4-ethylenedioxythiophene (EDOT) and 5-methylindole (5MeIn) was successfully carried out in acetonitrile containing lithium perchlorate as supporting electrolyte although the oxidation potentials of 5MeIn and EDOT were quite different. The influence of feed ratios and applied potentials on the copolymerization were investigated. The novel low band gap copolymers own both the advantages of P5MeIn and poly(3,4-ethylenedioxythiophene), i.e., good redox activity, good thermal stability, and high conductivity. The resulting copolymers were characterized by electrochemistry, FT-IR and ultra violet-visible spectroscopy, elemental analysis, thermal analysis, conductivity, and scanning electron microscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Pyrrole/N‐p‐toluenepyrrole copolymers in the presence of surfactants: A promising material for glucose sensing

In this study, pyrrole/N‐para‐toluenpyrrole (Py/NptPy) copolymers were synthesized by chemical oxidative polymerization method. The effects of different kinds of (anionic, cationic, and nonionic) surfactants on the properties of copolymer were investigated. The structural, morphological, thermal, and conductivity properties of the copolymers were investigated by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and the four‐probe measurement device respectively. FTIR spectra of copolymers synthesized in different environments that support the formation of copolymer. SEM results show that the morphologies of copolymers synthesized in the presence of surfactant are more homogeneous and the particle sizes are smaller than that of polypyrrole (PPy). TGA results revealed that the thermal stabilities of Py/NptPy‐NaDBS (400°C) and Py/NptPy‐Tween 20 (260°C) copolymers were higher than surfactant free Py/NptPy copolymer (180°C) according to their initial decomposition temperatures. It was determined that the conductivity values of copolymers were higher than PNptPy. Glucose sensor properties of copolymer synthesized in the presence of tetradecylthreemethyl ammonium bromide (TTAB) were investigated with cyclic voltammetry (CV) method. Michaelis–Menten constant of Py/NptPy‐TTAB copolymer modified electrochemical biosensor was calculated as 5.30 mM. POLYM. ENG. SCI. 56:995–1003, 2016. © 2016 Society of Plastics Engineers     

Synthesis and characterization of poly(butylene terephthalate‐co‐triethylene terephthalate) copolyesters

Poly(butylene terephthalate‐co‐triethylene terephthalate) random copolymers of various compositions and molecular weights were synthesized in bulk and characterized in terms of their chemical structure and thermal and rheological properties. At room temperature all the copolymers were partially crystalline and showed good thermal stability. The main effect of copolymerization was a decrease in the melting and glass‐transition temperatures with respect to the poly(butylene tere‐ phthalate) homopolymer. The fusion temperatures were well correlated with the composition by the Baur equation and the equilibrium melting temperature and the heat of fusion extrapolated values for poly(butylene terephthalate) were in good agreement with those reported elsewhere. Triethylene terephthalate units were found to influence the rheological behavior in the melt, the viscosity being significantly higher than that of the poly(butylene terephthalate‐co‐diethylene terephthalate) copolymers investigated previously. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 981–990, 2001     

Thermal energy storage by poly(styrene-co-p-stearoylstyrene) copolymers produced by the modification of polystyrene

A series of poly(styrene-co-p-stearoyl styrene) copolymers as novel polymeric solid–solid phase-change materials (SSPCMs) were synthesized by the modification of polystyrene with stearoyl chloride. The chemical structure and crystalline morphology of the synthesized copolymers were determined with Fourier transform infrared spectroscopy and polarized optical microscopy, respectively. The thermal energy storage properties and thermal stability of the SSPCMs were investigated with differential scanning calorimetry and thermogravimetric analysis, respectively. In addition, the thermal conductivity of the SSPCMs was measured with a thermal property analyzer. Moreover, thermal cycling tests showed that the copolymers had good thermal reliability and chemical stability after being subjected to 5000 heating/cooling cycles. The synthesized poly(styrene-co-stearoyl styrene) copolymers as novel SSPCMs have considerable potential for thermal energy storage and temperature-control applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Relationship between the absorption spectra and spatial hindrance in starch graft copolymers

The photochemical trans–cis isomerization of graft copolymers of azo dyes onto starch was studied in liquids spectrophotometrically. The relationship between the absorption spectra and spatial hindrance was investigated. The experimental results showed that the structure of the graft copolymers had a marked influence on photoisomerization. The smaller the spatial hindrance was, the easier the photoisomerization was. The copolymers showed better photoisomerization than their corresponding monomers, and this showed that the backbone of starch in the main chain influenced not the maximum‐wavelength position of the copolymers but the retroactive structure of the copolymers and favored their photoisomerization. In addition, the thermal cis–trans isomerization rate of the graft copolymers was studied in various polar solvents. The results suggested that the solvent polarity had a large effect on the thermal back‐isomerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2123–2126, 2006     

Synthesis of copolymers of tert‐butyl vinyl ether with maleic and citraconic anhydrides

In the present study, the effects of charge‐transfer complex formation and intramolecular fragmentation (side‐chain lactonization) in radical copolymerization of tert‐butyl vinyl ether (t‐BVE) with anhydrides of maleic (MA) and citraconic (CA) acids and the structure–thermal behavior relationships of the resulting copolymers were examined using the ¹H‐NMR, FTIR, DSC, and TGA analysis methods. It was shown that copolymerization under the chosen conditions proceeded through intramolecular fragmentation with the formation of γ‐lactone units. Side‐chain fragmentation of t‐BVE–MA and t‐BVE–CA copolymers also was confirmed by TGA and DSC analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2455–2463, 2006 2006     

Poly(styrene‐co‐maleic anhydride)‐graft‐fatty acids as novel solid–solid PCMs for thermal energy storage

A solid–solid phase change material (S‐SPCM) can store and release a specific amount of latent heat during its phase transition. In this regard, poly(styrene‐co‐maleic anhydride) (SMA)‐graft‐fatty acids (FA) copolymers were synthesized as novel S‐SPCMs for thermal energy storage (TES). The chemical structures of the SMA‐g‐FA copolymers were characterized by proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FT‐IR) spectroscopy techniques. The phase transformations of the copolymers form crystalline phase to amorphous phase were monitored using polarized optical microscopy (POM). The latent heat TES (LHTES) properties, thermal cycling reliability, and thermal stability of the S‐SPCMs were investigated by differential scanning calorimetry and thermogravimetric analysis methods. The SMA‐g‐FA copolymers produced as S‐SPCMs showed solid–solid phase transitions at about 40°C–60 °C range and had latent heat storage and release ability between 84 and 127 J/g, respectively. The S‐SPCMs had stable chemical structures and reliable LHTES characteristics even after 5,000 thermal cycling. They had reasonable thermal conductivity value changed in the range of 0.15–0.19 W/mK. Furthermore, it was concluded that the SMA‐g‐FA copolymers can be considered as promising S‐SPCMs for TES utilizations. POLYM. ENG. SCI., 59:E337–E347, 2019. © 2019 Society of Plastics Engineers     

Thiophene‐based copolymers synthesized by electropolymerization for application as hole transport layer in organic solar cells

Electrically conducting thiophene‐based copolymers were synthesized by electropolymerization. The potential range used has a strong influence on the film structure and properties. The extent of oxidation of the copolymers was determined from the ratio of the oxidation to reduction charge, Q_ox/Q_red. The use of wide potential range leads to reduced films, whereas the narrow range leads to partially oxidized films. The copolymers exhibit a characteristic band in UV–vis spectra at ～ 410 nm, which shifts to higher wavelengths for the more doped material. The electrical conductivity of the copolymers was correlated to their morphology and their structure. The copolymer with higher conductivity is partially reduced, has compact morphology and higher ratio of quinoid to benzenoid rings. The energy gap of the copolymers is reversely proportional to their electrical conductivity. The optical and electrical properties of the copolymers make them very well suited for use as hole transport layers (HTL) in organic opto‐electronic devices. We prepared polymer : fullerene solar cells with copolymer HTLs. The solar cell performance was tested with very encouraging initial results. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013