Synthesis and electrochromic properties of aromatic polyimides bearing pendent triphenylamine units

A series of aromatic polyimides with pendent triphenylamine group were synthesized from equimolar mixtures of 4,4′-oxydianiline (ODA) and 4-(3,5-diaminobenzamido)triphenylamine (4), 4-(3,5-diaminobenzamido)-4′,4″-di-tert-butyltriphenylamine (t-Bu-4) or 4-(3,5-diaminobenzamido)-4′,4″-dimethoxytriphenylamine (MeO-4) with two aromatic tetracarboxylic dianhydrides (DSDA or 6FDA) via a conventional two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical imidization. These polyimides exhibited good solubility in polar organic solvents and could be solution-cast into flexible and strong films. They showed excellent thermal stability, with T_g values in the range of 284–309 °C. The polyimides derived from diamines t-Bu-4 and MeO-4 exhibited reversible electrochemical oxidation, accompanied by strong color changes with high contrast ratio and electrochromic stability. For the polyimides derived from diamine 4, the coupling reaction between the triphenylamine radical cations occurred during the oxidative process forming a tetraphenylbenzidine structure, which resulted in an additional oxidation state and color change together with enhanced near-IR absorption at fully oxidized state.     

Synthesis,photophysical and iron-sensing properties of terpyridyl-based triphenylamine derivatives

A series of new terpyridyl phenyl/styryl triphenylamine chromophores were designed and synthesized. The branching number and the rigid/flexible bridge structures had a remarkable effect on the photophysical, selectivity and sensitivity for Fe(II) ion properties of these chromophores. The fluorescence lifetimes of the rigid terpyridyl phenyl triphenylamine chromophores are longer than that of the flexible terpyridyl styryl triphenylamine derivatives. The terpyridyl phenyl/styryl triphenylamine chromophores present an increasing fluorescence lifetime with the increase in the number of branches from 1 to 3. The terpyridyl flexible styryl triphenylamine derivatives have a higher sensitivity than that of the terpyridyl rigid phenyl triphenylamine derivatives for Fe(II) ion in neutral aqueous solution amongst other divalent metal ions such as Cu²⁺, Co²⁺, Ni²⁺, Hg²⁺, Mg²⁺, Pb²⁺, Zn²⁺.     

Synthesis,characterization, and properties of novel fluorine containing aromatic polyamides

A series of novel fluorine containing aromatic polyamides were synthesized by the direct polycondensation of various fluorine containing aromatic diamines and commercially available 5‐t‐butyl isophthalic acid. These polyamides have good solubility in several organic solvents such as dimethylformamide, N,N‐dimethylacetamide, 1‐Methyl‐2‐pyrrolidone, dimethyl sulfoxide, and tetrahydrofuran. The synthesized polymers exhibited inherent viscosities up to 0.93 dL/g and M_w up to 1,52,000 with PDI of 2.49. The polyamides exhibited good thermal stability up to 489°C for 10% weight loss in nitrogen and high glass transition temperature up to 273°C. Dynamic mechanical analysis showed a very good retention of storage modulus up to the glass transition temperature. The tan δ peak value at 1 Hz was used to calculate the T_g and these values are in good agreement with differential scanning calorimetry data. The polyamide films were flexible with tensile strength up to 72 MPa, elongations at break up to 14%, and modulus of elasticity up to 1.39 GPa depending on the exact repeating unit structure. X‐ray diffraction measurements indicate that these polyamides are semicrystalline. Rheology study showed same trend of melt viscosity behavior with different shear rate for all polymers. Water absorption study indicates the hydrophobic nature of the polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and the properties of novel cycloaliphatic-aromatic polyamides having pendent N,N'-diphenyl imido groups

: We have investigated a novel monomer having two pendent phenyl imido groups for preparing new cycloaliphatic-aromatic polyamides. Novel polyamides were synthesized by direct polycondensation reaction of N,N'-diphenyl-2,3,5,6-diimido cyclohexane-1,4-dicarboxylic acid(PICA) and various aromatic diamines such as p-phenylene diamine, 4,4'-oxydianiline and 4,4'-methylene dianiline. A direct polycondensation was carried out by a Yamazaki method which is typical of using triphenyl phosphite, lithium chloride, and pyridine. Inherent viscosity of these resulting polyamides are ranged 0.20 ∼ 0.45 dl/g. A transparent flexible and tough film was casted. The glass transition temperature of the polyamide from the PICA and 4,4'-oxydianiline is 147 °C. The decomposition temperature of these polyamides are ranged from 350 ∼ 360 °C and the ash contents of them orders MDA > p-PDA > ODA according to kinds of the using diamines. And the solubilities of these polyamides are good in aprotic solvents such as DMAc, NMP, DMF. Received: 26 July 1999/Revised version: 14 September 1999/Accepted: 28 September 1999     

Synthesis,characterization, and properties of novel aromatic polyamides containing phthalazinone moiety

A unsymmetrical and kink non-coplanar heterocyclic dicarboxylic acid monomer, 4-[4-(4-carboxy phenoxy)-naphthyl]-2-(4-carboxyphenyl)phthalazin-1-one (3) was successfully synthesized with high purity and high yields. A series of novel polyamides containing phthalazinone were prepared from the newly synthesized dicarboxylic acid with various aromatic diamines by means of the phosphorylation polycondensation reaction. Molecular weights of the obtained polyamides were evaluated viscometrically, and the inherent viscosities (η_inh) measured were in the range 0.54–0.69 dL/g. These polyamides were amorphous and readily soluble in many organic solvents, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimetheylformamide, dimethyl sulfoxide, pyridine, and m-cresol etc., and they could easily be solution-cast into transparent, flexible films with good mechanical properties, with tensile strength ranging from 63.9 to 81.6 MPa and elongation at break from 7.2 to 11.4%. These polymers still kept good thermal stability with high-glass transition temperatures in the range of 283–338 °C, and the decomposition temperature in nitrogen for a 10% weight-loss temperatures in excess of 490 °C, and char yield at 800 °C in nitrogen ranged from 56 to 63%. Furthermore, the polyamides films were essentially colorless; their cut-off wavelengths were between 365 and 379 nm.     

Synthesis and characterization of cubane polyamides

Cubylamines and cubylmethylamines are of interest as antiviral agents. Reliable syntheses of some polyamides with cubane as the backbone of a polymer chain are described. Two monomers of cubane, cubane‐1,4‐dicarboxylic acid (CDA) and 1,4‐diaminocubane (DAC), are used. Polymerizations of DAC, 1,6‐hexamethylene diamine and 1,4‐diaminobenzene with cubane‐1,4‐dicarbonyl chloride, adipoyl chloride and terephthaloyl chloride to obtain polyamides are discussed. The polymers were characterized by FTIR, ¹H NMR and ¹³C NMR spectroscopies. Characterization of the prepared polyamides by TGA and DSC show a highly exothermic peak above 200 °C. Hydrolysis of polyamides containing DAC were carried out in dialysis bags containing an aqueous buffer solution (pH 8) at 37 °C. Detection of the hydrolysis product by UV spectroscopy showed that DAC was released by the hydrolysis of the amide bonds in the polymer chain. © 2000 Society of Chemical Industry     

Synthesis and properties of silicon-containing polyamides

A series of aromatic polyamides incorporating silicon together with phenylquinoxaline or with hexafluoroisopropylidene groups has been synthesized by solution polycondensation of a silicon-containing diacid chloride with aromatic diamines having phenylquinoxaline rings or hexafluoroisopropylidene groups. These polymers are easily soluble in polar aprotic solvents, such as N-methylpyrrolidinone and dimethylformamide, and in tetrahydrofurane, and can be solution-cast into thin, transparent films having low dielectric constant, in the range of 3.26 to 3.68. These polymers show high thermal stability with decomposition temperature being above 400°C and glass transition temperature in the range of 236°C to 275°C. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1533–1538, 1997     

Synthesis and characterization of polyamides X 18

Step heating melt polycondensation was adopted in the preparation of polyamides based on 1,16‐octadecane diacid and α,ω? (CH₂)_2n diamines (n = 1–6). The structure was confirmed by various spectroscopic techniques (IR, Raman, ¹H‐NMR, and ¹³C‐NMR). High molecular masses were obtained only in the presence of an excess of diamine and when the diamine possessed low volatility. The molecular masses were between (0.94 and 2.1) × 10⁴ Da for all polyamides under consideration. An excellent correlation between size exclusion chromatography and ¹H‐NMR data was demonstrated in the measurement of the degree of polymerization. The melting temperatures of the polyamides decreased from polyamide 12 18 to polyamide 2 18 as the amide density along the molecular chain declined. No significant variation was observed in the glass‐transition and decomposition temperatures of the polyamides that were obtained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1565–1571, 2005     

Synthesis and photovoltaic properties of two-dimensional conjugated polythiophene derivatives presenting conjugated triphenylamine/thiophene moieties

In this study we synthesized three two-dimensional (2-D) polythiophene derivatives (PTs), namely PTBPTPA, PTStTPA, and PTCNStTPA, featuring three different conjugated units—biphenyl (BP), stilbene (St), and cyanostilbene (CNSt), respectively—in the polymer backbones and presenting conjugated triphenylamine/thiophene (TPATh) moieties on the side chains. In addition, we also synthesized three conjugated BP-, St-, and CNSt-based main-chain-type conjugated polymers (PTBP, PTSt, and PTCNSt, respectively). Incorporating the St and CNSt moieties into the polymer backbones and appending TPATh units induced high degrees of intramolecular charge transfer within the conjugated frameworks of the polymers, thereby resulting in lower band gap energies and red-shifting of the maximal UV–Vis absorption wavelengths. Moreover, the energy levels of the highest occupied molecular orbitals of the BP-, St-, and CNSt-based main-chain-type and 2-D PTs were lower than that of P3HT, implying that they would be applicable for the preparation of polymer solar cells (PSC) with greater open-circuit voltages. The photovoltaic performances of PSCs fabricated from blends of the 2-D PTs and the fullerene derivative PC₆₁BM were superior to those of PSCs based on the main-chain-type polymer/PC₆₁BM blends.     

Synthesis,characterization, and fiber studies of certain aromatic polyamides

Three aromatic polyamides containing alkyl and ether linkages in the main chain were synthesized, using low-temperature solution and interfacial polycondensation procedures, and were characterized by viscosity, solubility, UV, IR, TGA, and DSC studies. Fibers were spun using a laboratory-scale wet spinning unit and their mechanical and morphological properties studied. The results were correlated with structure and spinning conditions.     

Synthesis,characterization and fluorescence quenching of conjugated polymer containing triphenylamine group

Poly(triphenylamine-p-phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation. The structures of two copolymers were characterized. Ultraviolet and visible spectroscopy (UV-Vis) and photoluminescence (PL) spectra show the end-capped polymer emits intensive green light in both solution and film state. Their applications in the detection of nitro compounds were investigated, and the results show high fluorescence quenching sensitivity of the end-capped polymer towards o-nitrotoluene (o-NT). When the concentration of o-NT was 21.5 × 10^-3 mol/L, the fluorescence quenching reached 96%. Additionally, after the exposure of polymer film in three different quenchers such as dinitrotoluene (DNT), p-nitrobenzoquinone (p-BQ) and p-nitrotoluene (p-NT) for 600 s, its fluorescence quenching reached 93.6%, 11.5% and 77.9%, respectively. This kind of polymer has great advantages in preparation and may find applications in the detection of nitro explosives.     

Synthesis, characterization and electrochromic properties of a conducting copolymer of pyrrole functionalized polystyrene with pyrrole

A well-defined polystyrene (PSt) based polymer containing at one end-chain 3,5-dibromobenzene moiety, prepared by atom transfer radical polymerization (ATRP), was modified in two reaction steps. First one constitutes a Suzuki coupling reaction between aromatic dibromine functional polymer and 3-aminophenylboronic acid, when a diamino-containing intermediate was obtained. The second step is a condensation reaction between the diamino functional polystyrene and 2-pyrrole aldehyde. Thus, a polymer containing a conjugated sequence having pyrollyl groups at the extremities was synthesized. The presence of oxidable pyrrole groups in the structure of the polymer permitted further electropolymerization. The structures of intermediate polymers were analyzed by spectral methods (¹H NMR, FTIR). Electrochemical copolymerization of pyrrole functionalized polymer (PStPy) with pyrrole was carried out in acetonitrile (ACN)-tetrabutylammonium tetrafluoroborate (TBAFB) solvent electrolyte couple. Characterization of the resulting copolymer were performed via Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), spectroelectrochemical analysis, and kinetic study. Spectroelectrochemical analysis show that the copolymer of PStPy with Py has an electronic band gap (due to π-π* transition) of 2.4 eV at 393 nm, with a yellow color in the fully reduced form and a blue color in the fully oxidized form. Via kinetic studies, the optical contrast %ΔT was found to be 20% for P(PStPy-co-Py). Results showed that the time required to reach 95% of the ultimate T was 1.7 s for the P(PStPy-co-Py).     

Synthesis, characterization and fluorescence quenching of conjugated polymer containing triphenylamine group

Poly(triphenylamine-p-phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation. The structures of two copolymers were characterized. Ultraviolet and visible spectroscopy (UV-Vis) and photoluminescence (PL) spectra show the end-capped polymer emits intensive green light in both solution and film state. Their applications in the detection of nitro compounds were investigated, and the results show high fluorescence quenching sensitivity of the end-capped polymer towards o-nitrotoluene (o-NT). When the concentration of o-NT was 21.5 × 10⁻³ mol/L, the fluorescence quenching reached 96%. Additionally, after the exposure of polymer film in three different quenchers such as dinitrotoluene (DNT), p-nitrobenzoquinone (p-BQ) and p-nitrotoluene (p-NT) for 600 s, its fluorescence quenching reached 93.6%, 11.5% and 77.9%, respectively. This kind of polymer has great advantages in preparation and may find applications in the detection of nitro explosives. __________ Translated from Journal of Functional Polymers, 2008, 21(1): 11–16 [译自: 功能高分子学报]     

Synthesis,characterization and properties of an electroactive polymer having oligoaniline and binaphthyl units

A novel polymer containing oligoaniline and binaphthyl units, exhibiting an exciting molecular structure, interesting spectroscopic and electrochemical properties, has been synthesized through oxidative coupling polymerization. The polymerization characteristics and chemical structure of the polymer were systematically studied. The oxidation state and doping level of the polymer were evaluated through X-ray photoelectron spectra. In addition, cyclic voltammetry results suggest that the obtained polymer has an intrinsic electrochemical activity similar to polyaniline. In the case of the optically active polymer, we observed a specific Cotton effect and an ultra high value of the specific rotation of the polymer solution. What is more, the conductivity of the polymer was about 3.26 × 10^?6 S cm^?1 at room temperature upon preliminarily protonic-doped experiment.     

Novel chalcone-based aromatic polyamides: synthesis,characterization, and properties

Two novel diacid-based monomers have been synthesized by anchoring a benzylideneacetophenone (chalcone) moiety through an amide or ester bridge at the fifth position of the isophthalic acid ring. Two series of new polyamides bearing chalcone side chains were prepared by direct polycondensation reaction of the aforementioned dicarboxylic acids and various aromatic diamines in N-methyl-2-pyrrolidinone, using triphenyl phosphite and pyridine as condensing agents. Their molecular structure and the basic properties were investigated by nuclear magnetic resonance, Fourier-transform IR and UV–vis spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction. The inherent viscosity, molecular weights measurements (by gel permeation chromatography), water uptake, and solubility tests completed the research study. Introduction of the rigid and bulky chalcone units into the polymer side chains improved remarkably the solubility of the aromatic polyamides, endowed them with an amorphous nature, good thermal stability, and photosensitivity. The resulting polymers were obtained in good yields, inherent viscosities varied between 0.49 and 0.86 dL/g, and their relative high molecular weights conferred them film-forming properties. They were soluble in amide-type polar solvents, such as N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. These polyamides had glass transition temperatures between 219 and 264 °C, and 10% weight loss temperatures in the range of 394–436 °C and around 50% residue at 700 °C in nitrogen atmosphere. The polyamides underwent a [2 + 2] photocycloaddition reaction upon UV light irradiation both in solution and film state in the absence of a photoinitiator or photosensitizer. The polymer films became insoluble in solvents as a result of the crosslinking .     

Synthesis and characterization of photoelectronic polymers containing triphenylamine moiety

Several polymers containing triphenylene moieties in main chain were synthesized by Knovenagel or Wittig condensations. The polymers were characterized by ¹H NMR, IR, GPC, TG, UV–vis, FL and CV. Results indicated that PNB, which was prepared from the polycondensation of 4,4′-dialdehyde-4″-n-butyltriphenylamine with 1,4-bis(triphenylphosphonionmethyl)benzene dibromide, is the most thermally stable one and that PNP, which was prepared from the polycondensation of 4,4′-dialdehyde-4″-n-butyltriphenylamine with p-phenylene diacetonitrile, is the most thermally instable one. The fluorescence quantum efficiency of PNB is 94.3%, which is a high value for optoelectronic polymer materials. All the polymers have a similar CV curve with a reversible oxidation peak and two reduction peaks except that PNB has a single reduction peak.     

Synthesis and structural characterization of novel multifunctional polysiloxanes having photo-refractive properties

A novel series of multifunctional polysiloxanes with photo-refractive properties have been synthesized via a hydrosilylation reaction with 9-allylcarbazole (ACZ) as charge-transporting agent, 1-allyloxyl-2,5-dimethyl-4-(4-nitro-phenylazo)benzene (ADNPAB) as electro-optical chromophore and poly(hydrogenmethylsiloxane). The component concentrations in the polymers can be controlled by different reagent ratios between ACZ and ADNPAB. The structural characterization of the polymers is presented, together with ¹H NMR, IR spectra and elemental analysis. © 1999 Society of Chemical Industry     

Synthesis and characterization of inherently coloured azo polyamides

Six intrinsically coloured azo polyamides have been prepared by interfacial polycondensation and characterized by visible, ultra-violet and infra-red spectroscopy, viscometry and differential thermal analysis.     

A novel electrochromic polymer containing triphenylamine derivative and pyrrole

A novel conducting polymer was successfully synthesized via electropolymerization of N¹,N⁴-bis(4-(1H-pyrrol-1-yl)phenyl)-N¹,N⁴-diphenylbenzene-1,4-diamine (DPTPA). This polymer film exhibited six various colors under different potentials. Besides, this polymer film showed high optical contrast (41% at 852 nm, 52% at 617 nm) and fast switching time (1.3 s at 410 nm, 1.4 s at 852 nm and 0.6 s at 617 nm). Cyclic voltammogram and electro-optical study showed that the polymer film has a stable and well-defined reversible redox process as well as electrochromic behavior.