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The influence of nanosized cerium oxide as an active filler on the mechanical properties and thermal stability indices and heat resistance of films of thermally stable aromatic polyimides of various chemical structures is studied. It is shown that, depending on the polyimide structure the introduction of cerium oxide nanoparticles into the film can lead to a noticeable increase or a significant decrease in the thermal stability of the material during thermo-oxidative degradation. It is found that the thermal stability of the films increases significantly when polyimides containing sulfonic groups in elementary units serve as matrix polymers. The introduction of cerium oxide nanoparticles into such polyimides leads to an increase in the thermal stability of the films in air by 20–40°C. Moreover, in an inert medium the thermal stability indices for the films of matrix polymers and nanocomposites differ slightly. For all the studied polyimides, the introduction of cerium oxide does not cause a noticeable change in the glass transition temperature but in some cases leads to limitation of the compliance of the films in the temperature range above the glass transition.

A number of new substituted pyrido-[3,2-g]quinoline-3,7-diamines are synthesized, and copolyamides containing main-chain anthrazoline groups based on them are obtained. The mechanical, thermal, molecular-mass, and luminescent characteristics are investigated. All polymers have high mechanical properties and heat resistance. It is shown that the anthrazoline-containing copolyamides with carboxyl groups in positions 4 and 6 possess intense luminescence in the range of 590–620 nm.

A comparative study of physicochemical parameters and transport properties of the heteroaromatic polymer polybenzoxazinoneimide (PBOI) and its hydrolytically stable prepolymer, imide-containing polyamic acid (PI-PAA), has been performed. The process of thermal conversion of PI-PAA into PBOI has been studied using thermogravimetric analysis, differential scanning calorimetry, and mass spectrometry. The conversion of PI-PAA into PBOI increases the glass transition temperature and the density of the polymer, resulting in a reduction of fractional free volume. Both of the test polymers have been examined as membrane materials in pervaporation dehydration of aqueous isopropyl alcohol. It has been shown that PBOI is more effective in this process compared with the prepolymer. The transport properties of the PBOI membrane have been compared with published data on other polymers used in the pervaporative separation of the water–isopropanol azeotrope.

Structural, molecular, and hydrodynamic characteristics of thermostable functionalized polymers [polyamic acids (PAAs) with biquinoline chelate groups in the main chain] were studied by high-performance liquid chromatography. Size exclusion mechanism of chromatography in conditions including suppression of polyelectrolyte swelling and ion-exclusion effects was proved. The influence of molecular and structural characteristics of PAAs on their ability to form metal–polymer complexes (MPCs) with copper(I) chloride was studied. The critical polymer concentration at which binding of two PAA macromolecules with Cu+ ion takes place to form MPCs was estimated.

Novel polymer macroligands—copolyamides containing different quantity of bipyridyl groups—were obtained from 4,4′-diamino-2,2′-bipyridine, 4,4′-diaminodiphenyl ether and terephthaloyl-bis(3-methoxy-4-hydroxybenzoic) acid dichloroanhydride by low-temperature polycondensation. Metal–polymer complexes with different content of Ir(ppy)2 were obtained by the interaction between polymer ligand and [Ir(ppy)2Cl]2 (ppy–2-phenylpyridine). The properties of films and coatings based on these materials were studied.

Polyamides containing fragments of two cyanine chromophores in the main chain are synthesized, and their viscometric and electro-optical properties in solutions, as well as their stress-strain properties in films, are investigated. It is shown that the molecular characteristics of the copolyamides are substantially affected by chromophore fragments at a content of 10 mol %, while the mechanical properties of the films are independent of the chemical structures of chromophores incorporated into polyamide chains.

The photoluminescence properties of Tb3+ and Eu3+ complexes with polymer ligands containing various kinds of complexing groups—namely, carboxyl (5–20 mol %), pyridylquinoline (5 mol %), or pyridylnaphthyl (5 and 10 mol %) groups—in solution and block are considered. The chemical structure of a neutral comonomer (methyl methacrylate; styrene; isopropyl-, phenyl-, or benzylmethacrylamide; and N-vinylamides) in polymer ligands is varied. The intensity of photoluminescence is dependent not only on the chemical nature of a complexing group but also the chemical nature of a neutral comonomer and a spacer. Variation in the nature of a comonomer and a ligand makes it possible to prepare complexes in which a high luminescence of a low-molecular-mass complex is preserved and advantages inherent in a polymer complex are acquired. The effect of the nature of the polymer matrix (photoactive and photoinert) on the efficiency of electronic-excitation energy transfer is ascertained. The data on the photoluminescence of metal-polymer complexes that are based on polymer ligands containing vinylcarbozole units and that possess hole conductivity make it possible to regard them as materials for electroluminescence. The intensity of photoluminescence of these complexes is related to the competition of oppositely directed photophysical processes in a macromolecule: formation of excimers and migration of electronic excitation energy. An analysis of the published data and of the results of the authors shows that detailed studies of these polymer systems in solution and in matrices are needed to gain insight into the relationship between photo- and electroluminescence properties of metal-polymer complexes, because the matrix plays different roles in photoluminescence and electroluminescence (inner filter or conduction); as a consequence, the emission spectra may differ appreciably. It is shown that the efficiency of electroluminescence may be improved if the transfer of energy from the lanthanide ligand in a complex to the conducting matrix is decreased.

A series of copolyamides carrying side bipyridyl-containing groups and their metal-polymer complexes with iridium were synthesized. The stress-strain, thermal, molecular-weight, and luminescent characteristics of these compounds were examined. All the polymers synthesized exhibit high performance in the stress-strain characteristics and high thermal stability.

The Suzuki reaction with polymeric Ni catalysts based on the biquinolyl-containing polyamic acids can be carried out under conditions close to the conditions used for the catalytic transformations in the presence of PdII complexes with the same polymeric ligands. However, the yields of the cross-coupling products on the Ni catalysts are somewhat lower than those obtained in the presence of palladium complexes. The yield of the cross-coupling product increases with the increase in the conformational mobility of the polymeric ligand. Unlike catalysis by palladium complexes, in catalytic transformations by nickel complexes activation of the catalyst is required. Such an activation can be carried out either by addition of chemical reducing agents or by applying the corresponding cathodic potential (−0.8 V relative to Ag/AgCl/KCl). The electrochemical activation was shown to lead to higher yields of the cross-coupling product than the use of chemical reducing agents.

A procedure for functionalization of the surface of multiwall carbon nanotubes, based on treatment of the nanofiller with a strong oxidant and 1-hexadecylamine and aimed to improve the compatibility of nanotubes with a polypropylene matrix, was examined. Variation of the mechanical and electrical properties of the composite fiber based on polypropylene in relation to the concentration of the modified nanotubes was studied.

A novel monomer, viz., bipyridyl-containing dicarboxylic acid, was synthesized from 6-pyridyl-3,4-pyridine dicarboxylic acid anhydride and 5-aminoisophthalic acid. Novel polymer macroligands, viz., copolyamides containing 5, 15, 30, and 45% of the bipyridyl side groups, were obtained based on this monomer by low-temperature polycondensation. Metal polymer complexes (MPC) with different Ir(ppy)2 content were synthesized by the reaction of the polymer ligand with the binuclear complex [Ir(ppy)2Cl]2 (ppy is 2-phenylpyridine) and their properties were studied.

The molecular imprinting technique is used for the synthesis of monodisperse polymer particles via the seed emulsion copolymerization of methyl methacrylate, ethylene glycol dimethacrylate, and comonomers based on Nile Red. The introduction of lower alcohol templates into the reaction mixture and their removal after the synthesis lead to the formation of molecular-recognition sites in the shell that contain luminophore groups and give an optical response to the presence of methanol and ethanol in the gas phase. The particles are investigated via electron microscopy and dynamic light scattering, and their specific surface area is determined through the BET method. The kinetics of a change in the luminescence of thin films based on the particles in vapors of lower alcohols is investigated.

Polyamic acids containing biquinolyl (biQ) fragments in the polymer backbone are capable of coordinating with NiII ions to form two types of coordination units: with one or two biQ ligands in the Ni coordination environment. The relative number of [Ni(biQ)2]2+ coordination units in the polymer chain increases with an increase in the concentration of the biQ fragments in solution and with a decrease in the conformational rigidity of the polymer. The synthesis of the nickel complexes with the polymer ligands can be carried out using both Ni salts and the electrochemical dissolution of the Ni anode.

A study of the application of polyamic acids (PAA) and polyamidoimides (PAI) in manufacturing passivate and protective coatings for the crystal front facet of a semiconductor laser was carried out. The morphology of the surfaces of the deposited films was studied using atomic force microscopy. The structure of the deposited films and their roughness were examined. An analysis of the watt-ampere characteristics of the laser diodes showed that films based on polyamic acids markedly increase the magnitude of the peak power of semiconductor lasers. The highest value of the peak power was obtained for coatings based on polyamic acids instead of polyamidoimides. The value of the peak power for laser structures with a coating based on polyamic acids is 1.3 times higher than for structures without a polymer coating.

Polyamides containing main-chain cyanine chromophores are synthesized, and their molecular, nonlinear optical, and mechanical properties are studied. It is shown that the Kerr electro-optical effect in polymer solutions is determined by the rigidity of polymer chains and that the nonlinear optical properties are dependent only on the chromophore content.

Successive molecular assembling in polymer chains furnished a series of the comb-shaped copolymers of 4-aminostyrene containing side styrylquinoline chromophore groups. Thermal, thermomechanical, spectroscopic, and luminescent properties of the polymers and low-molecular-weight model chromophores were studied.

Copolymers of N-vinylcarbazole and methyl methacrylate carrying side pyridylquinoline groups are synthesized on the basis of the methacrylol derivative of 2-pyridylquinoline-4-carboxylic acid hydrazide. It is shown that the copolymers form stable metal-polymer complexes with Ir(ppy)2Cl (ppy = 2-phenylpyridine). The spectral and photoluminescent properties of the metal-polymer complexes are studied.

Monodispersed core-shell particles 290–315 nm in diameter were prepared by seed emulsion copolymerization of styrene with divinylbenzene in the presence of luminophore-containing comonomers. The capability of the particles obtained to sorb toluene vapor was shown by solid-state 1H and 13C NMR spectroscopy.

New polyamides derived from 2-(4-aminophenyl)-5-aminopyridine, 4,4-diaminodiphenyl ether, and 4,4′-terephthaloyloxybis(3-methoxybenzoic) acid dichloride were prepared. These polyamides are of interest as macromolecular ligands. The deformation-strength, thermomechanical, and thermal properties of films of polyamides with various content of phenylpyridine fragments were studied.

The newly synthesized complex (2) of copper(I) chloride with di-n-hexyl 2,2′-biquinoline-4,4′-dicarboxylate (L) was spectroscopically and electrochemically characterized. The X-ray diffraction study showed that the crystals of complex 2 consist of the dinuclear moieties [L2Cu1 2(μ-Cl)2] containing Cu2(μ-Cl)2 clusters. Spectrophotometric studies and ESI-mass spec-trometric measurements showed that after the dissolution of complex 2 in acetonitrile (AN) and N-methyl-2-pyrrolidone (NMP), the solution contained not only the dinuclear complexes [L2Cu1 2(μ-Cl)2] but also [L2Cu1]Cl, [LCu1Cl(Sol)], and [Cu1Cl(Sol)] (Sol is the solvent). The electrochemical data also confirm the conclusion that bridged dinuclear chloride complex 2 dissociates both in NMP and AN to form the tetrahedral bis-biquinoline complex [L2Cu1]Cl. In solutions of complex 2 in alcohols and N,N-dimethylformamide (DMF), only [L2Cu1]Cl and [Cu1Cl(Sol)] are present. In EtOH, AN, and DMF, [Cu1Cl(Sol)] undergoes disproportionation to [Cu11Cl(Sol)] and Cu0.

For films based on poly(amidoimide) with a comb-shaped structure and long side chains, the specific features of the mechanical and thermomechanical behavior and their dependence on the concentration of the above chains are studied. With variation of the composition of the material, changes in the mechanical characteristics show a nonmonotonic character. Comparison of the results of mechanical tests and densimetric measurements allows certain conclusions to be drawn about the character of variations in the structural organization of films with an increase in the concentration of side fragments in macrochains. The role of plasticization in the behavior of the above materials during heating is demonstrated. The advantages of the practical use of the above phenomena for the optimization of the regimes of thermally stimulated polarization of films are discussed.

A method for electrosynthesis of heteropolynuclear biquinoline-containing CuI and PdII complexes using sacrificial Cu and Pd anodes was developed. The sequence of anode dissolution (first Pd and then Cu) was important for the synthesis of the complex. The opposite sequence of dissolution resulted in oxidation of the initially formed CuI ions to CuII. The obtained CuI and PdII complexes with polymer ligands had high catalytic activity in the reaction of aryl halides with phenylacetylene giving rise to a C(sp2)-C(sp) bond. The yield of arylphenylacetylene in the presence of 0.1 mol.% of Pd catalyst in relation to the starting halide was 50–90% depending on the nature of the aryl halide.

Poly(amido acids) with main-chain metal-binding ligands methylene-bis(anthranilic acid) and their linking fragments of a widely varied structure have been synthesized. The chemical structure of poly(amido acids) that affect the luminescence of Tb3+ and Eu3+ ions and interact with them is studied, and the mechanism of this effect is advanced.

Electrochemical dissolution of sacrificial Pd anode was used to synthesize novel polynuclear PdII complexes with ligands based on polyamic acids containing in the main chain biquinolyl groups capable of coordination to the metal ions. The synthesized polymeric complexes exhibit high catalytic activity in the Suzuki reaction. The reaction can be run under mild conditions, at 40 °C and with a sufficiently high product yield at a catalyst concentration of 0.05 mol.% (with respect to the starting aryl halide). The polymeric ligand allows immobilization of the catalyst on the graphite fabric with high specific surface area that enhances the catalyst turnover number and promotes its recycling.

A series of fibrous composites, carbon- and glass-reinforced plastics based on heat-resistant polyimide binders, were prepared. The viscoelastic and strength properties of the composites obtained confirm the enhanced heat resistance of the binders.

Method of electrochemical synthesis of new Cu-containing polyheteroarylenes that have biquinolyl units in their main chain is developed on the base of the soluble anode technique. The study of electrochemical properties of thus obtained Cu-containing polymer and the corresponding monomer complex revealed existence of two types of coordination environment: (1) copper Cu(I) in the tetrahedral surrounding of two biquinolyl ligands and (2) copper Cu(I) bound with only one biquinolyl fragment. The complexes with one biquinolyl polymer ligand showed high activity as catalysts for O2 reduction in the presence of hydroquinone that is converted to quinone in the course of the reaction.

Interaction of ITA-31 polyimide binder with a series of industrial sorbents based on styrene and vinylpyridine derivatives was studied.

A number of styrylquinoline chromophores with carboxyl groups have been prepared through the interaction of 2-methylcinchonic acid with aromatic aldehydes of various chemical structures. The copolymer of glycidyl methacrylate and methyl methacrylate carrying side epoxide groups has been synthesized, and the chemical modification of the copolymer with the above chromophores has been performed. The thermal, spectral, and nonlinear optical properties of the chromophores and modified polymers have been studied.

Structural reorganization of polyamide (PA) and low-molecular-weight CuI and CuII complexes with biquinolyl (biQ) ligands during their mutual redox transformations in solution was studied using the electrochemical methods (cyclic voltammetry and preparative electrolysis) and quantum chemical DFT calculations. The influence of electronic factors and geometry distortions in the complexes on the ionization energy on going from CuI to CuII was evaluated in comparison. The catalytically active form of the [CuI(PA)L2]BF4 complex can be synthesized in situ from the stable tetrahedral complex [CuI(PA)2]BF4 by the series of successive redox transitions CuI → CuII → CuI accompanied by the loss of one biQ-containing macroligand.

New polyamic acids with biquinoline units in the backbone, which are prepolymers of polybenzoxazinones, as well as their metal-polymer complexes containing [Ru(bpy)2]2+, were prepared. The electronic structure of these polymers was studied with the use of cyclic voltammetry, electronic absorption spectroscopy, and quantum-chemical calculations, and the location sites of electronic changes upon electrochemical reduction and oxidation were determined.

New polyamide acids (prepolymers of polybenzoxazinimides) containing 2,2-biquinolyl units in their main chain are synthesized. It is shown that these polymers form stable complexes with acids derived from the transition and rare-earth metals. The results of photophysical studies support the assumption that the process of generation of free charge carriers via a state of a pair bound by a Coulomb interaction includes two stages and that metal-polymer complexes are involved in this process. The quantum yield of photogeneration amounts to 0.007–0.05.

The thermochemical reactions of polyimide binder with various allotropic forms of carbon, fullerene C60 and ultradispersed artificial diamonds, were studied by thermal and spectral analyses.

A new method was elaborated for the introduction of chromophores into the side chains of polymers by esterification of polyamidoimides containing side carboxy groups with glycidyl ethers of dyes, 4-(4-nitrophenylazo)phenol and 4-(6-nitrobenzothiazol-2-ylazo)phenol. The optimum modification conditions were found that made it possible to esterify 15, 30, 50, and 90% of the carboxy groups. The synthesized polymers possess valuable physicomechanical properties (E = 2.8–3.3 GPa, σu = 69–90 MPa, eu = 38–77%) and glass transition temperatures of 115–125 °C, depending on the degree of esterification. After chromophore orientation in the corona discharge, all the polymers demonstrate nonlinear optical properties of the second order.

A new method for modifying polymers with side carboxyl groups by glycidyl ethers of hydroxyl-containing azobenzene dyes has been developed. The spectral, thermomechanical, and photosensitive properties of dye-modified polyamide-imides have been studied as a function of the dye content in a polymer. The films of polymers under study were shown to be almost transparent at wavelengths above 500 nm. The mobility of side chromophore groups is rather high, which makes these polymers promising for nonlinear optical applications. The polymers are characterized by a photosensitivity of 103–104 cm2 J−1, which can be significantly increased by doping with diphenylamide molecules, which transport charge carriers.

Statistical ensembles of microdomains formed on the surface of polyimide films based on pyromellitic dianhydride and 2,7-diaminofluorene during thermal imidization were described in terms of the model of reversible aggregation using the electron-microscopic data. Parameters of the statistical distribution were determined for each ensemble depending on the film heating temperature.

Film and fibrous materials derived from vanillic acid, one of promising products from processing of industrial lignin, were prepared and characterized. Thermochemical reactions of degradation and carbonization of films and fibers of vanillic acid polyesters and polyamides were considered, and the main relationships of thermal transformations of the materials were revealed.

Electrocatalytic oxidative coupling of terminal alkynes in the presence of atmospheric oxygen catalyzed by CuI complexes with polymeric biquinolyl ligands leads to the corresponding diynes in high yield. The reaction proceeds under mild conditions at a potential of CuII/CuI electroreduction (−0.55 V vs. Ag/AgCl/KCl) and is accompanied by O2 reduction to H2O.

The manifestation of current instability as an S-shaped I-V characteristic was detected in thin films of a metal-polymer complex of polyamide acid with Tb+2. The current instability characteristics are comparable to those of the switching effect in chalcogenide glasses. The origin of the current instability in the metalpolymer complex may be related to electrothermal switching. The threshold voltage and current in films ∼0.1 µm thick are 3–7 V and (2−1)×10−2 A/cm2, respectively.

A set of new metal-polymer complexes has been synthesized on the basis of polymers containing biquinolyl units in the main chain and Ru(bPy2)Cl2. The spectral and mechanical properties of these complexes were studied, as well as their photosensitivity in the temperature range from 20 to 150°C. It was shown that the photosensitivity of synthesized polymers is 2×104 cm2 J−1 and the quantum yield of carrier photogeneration is η=0.025.

The basic optical and electrical properties of polyamide acid and its complex with Tb+2 have been studied. The occurrence of room-temperature photoluminescence (PL) with an emission peak at 520 nm is established. The activation energy of conductivity at temperatures above 350 K is 2.1 eV. Polyamide acid is comparable in PL intensity with an electroluminescent polymer, poly(p-phenylvinylene).

M. Ya. Goikhmana, N. P. Yevlampievab, N. V. Kamaninac, I. V. Podeshvoa, I. V. Gofmana, S. A. Mil’tsovd, A. P. Khurchakb, and A. V. Yakimanskiia a Institute of Macromolecular Compounds, Russian Academy of Sciences, Bol’shoi pr. 31, St. Petersburg, 199004 Russia b Fock Institute of Physics, St. Petersburg State University, Ul’yanovskaya ul. 1, Petrodvorets, St. Petersburg, 198504 Russia c NPK Vavilov State Optical Institute, Birzhevaya liniya 12, St. Petersburg, 199034 Russia d St. Petersburg State University, Universitetskii pr. 26, Petrodvorets, St. Petersburg, 198504 Russia e mail: mgoikhman@yandex.ru

The phase-aggregate state of polyamidoimide films, and their blends and copolymers based on dicarboxypphenylphthalimide dichloride and 4,4′-diaminodiphenyl etherm 4,4′-bis-amino phenoxydiphenylsulphone and 3,3′-bis aminophenoxydiphenylsulphone is studied by diffraction and thermomechanical methods. The homopolymers have a mesomorphic X-ray with the exception of polyamidoimides based on 3, 3′-bis aminophenoxydiphenyl structure. The copolymers under study have a block structure, the 4,4′-diaminodiphenyl sulphone. ments having a dominant role. When the content of these fragments is 30 mole %, ether fragrearrangements are observed in both the copolymers and mechanical blends of the structural polyamidoimides.