Abstract: On the basis of the similarity between polymerization on a macromolecular template (matrix polymerization) and the formation of the particles of a new phase controlled by macromolecules, we suggested a model of a pseudomatrix process, in which the recognition of a macromolecule and a growing particle terminates the particle growth, because the surface of the particle becomes shielded by the polymer. Equations relating the mean particle size and the particle size distribution to thermodynamic parameters describing the interaction between macromolecules and particles were derived. It was demonstrated that even for very weak interactions that are comparable to the energy of thermal motion (for metals, the interaction energy may be not greater than a few tenths of percent of the surface energy) the particles formed must have a cross-section of about a nanometer and a very narrow size distribution. This conclusion agrees with the experimental data on the dimensions of the particles of a new phase, for example, metal sols formed in polymer solutions. The equations may be used for quantitative calculations of the energy parameters of the polymer-particle interaction and the targeted synthesis of nanocomposites involving a polymer and particles of specified size.

Abstract: Poly(3-hydroxybutyrate) membranes, obtained by casting of a chloroform solution, were studied by method of wide-angle X-ray scattering (WAXS). The membranes typically have an axial texture of the crystalline phase, with the polymer chain oriented predominantly perpendicularly to the membrane plane. Intensity of the (020) reflection, which served as quantitative characteristics of the degree of texture perfection, was measured for various inclination angles of the sample. It is concluded that membranes contain oriented (66%) and unoriented crystallite fractions. The values of the orientation function are presented.

Abstract: Data available in the literature on the biologically active derivatives of poly(acrylic acid) (PAA) and their possible application in pharmacology and medicine are summarized. The properties of various compounds, including the PAA salts with metals, organic and organometallic bases, PAA derivatives (esters, anhydrides, amides, etc.), interpolymer complexes, and copolymers of PAA and its derivatives, are considered, and their pharmacological activity and interactions with biological substrates are described.

Abstract: The paper summarizes data reported during the last 10-15 years on the sol-gel transition and the structure and properties of critical gels in polymer systems. Experimental data are considered that confirm the validity of a power law for the dependence of the static properties of critical gels (viscosity, equilibrium modulus of elasticity) on the distance from the critical point on the temperature scale and the dependence of dynamic rheological properties (stress relaxation, creep, spectrum of relaxation times, storage and loss moduli) on the duration and frequency of the mechanical action. A difference between the critical characteristics for the above properties in different systems are established, and some special features of the rheological properties at various values of the critical index are considered. Experimental data are compared with the results obtained by using theoretical descriptions of the critical gels, based on the theory of critical phenomena, percolation model, and fractal concepts. It is shown that the behavior of critical gels exhibits a universal character, while the values of critical indices are not universal and depend significantly on the structure of chemical network, type of the chemical reaction involved in the network formation, and the conditions of cross-linking. Factors determining this behavior are considered.

Abstract: For the membrane based on sulfonate-containing aromatic polyamides, pervaporation separation of water from water-alcohol mixtures was investigated. The selectivity and permeability of the membranes were studied as a function of the composition of the selective layer and the nature of counterion of the sulfo acid group. The composition of the selective layer was controlled by varying the ratio between terephthalic and isophthalic acid chlorides in the polymer chain. The selective layer based on polyamides containing equal molar fractions of terephthalic and isophthalic components was shown to be characterized by maximum selectivity and permeability. The selectivity coefficient depends on the nature of the counterion and increases in the following order: Na + < K + < Cs + < N + (C 2 H 5 ) 4 ≤ poly(ethylenimine). In the last case, the selectivity coefficient (the ratio between the molar fractions of the water and solvent in the permeate) was equal to 5.5 x 10 3 for the pervaporation separation of water-butanol mixture. The diffusion coefficient of water and its dependence on partial water vapor pressure were found to be determined by a configurational chain structure.

Abstract: The copolymers of acrylamide with N-(2-D-glucose)acrylamide were synthesized. It was shown that the reaction of these copolymers with concanavalin A yields hydrogels whose degree of swelling is controlled by the molar ratio between the units of N-(2-D-glucose)acrylamide and concanavalin A. For the reaction of the resulting hydrogels with a glucose solution, it was found that there exists a threshold concentration of glucose, above which the hydrogel transforms quickly into a soluble state.

Abstract: The synthesis of oligodienes by the mechanism of the living polymerization, initiated by organolithium compounds, was studied from the standpoint of obtaining products with a maximum degree of molecular homogeneity. The possible reasons leading to the formation of molecules with functionality defects, polymodal molecular mass distribution, and an inhomogeneous backbone microstructure are analyzed. The present-day state of analysis of the distribution of oligodienes with respect to the functionality types is discussed. The properties of the organolithium initiators of various types, described in the literature, are critically analyzed with respect to their application in the synthesis of molecularly-homogeneous oligodienes with terminal functional groups.

Abstract: Fluorescent properties of the bimetallic complexes of Eu(III) and Tb(III) with a copolymer of acrylic acid and ethyl methacrylate were studied. The results of the kinetic luminescent spectroscopy and the analysis of the fluorescence excitation spectra indicate that efficient energy transfer takes place from Tb 3+ to Eu 3+ . The intensity of Eu 3+ fluorescence at 615 nm is maximally enhanced at the Eu: Tb ratio 1: 1.

Abstract: Polymerization of butadiene with the catalytic system NdCl 3 .3TBP-i-C 8 H 17 MgC 4 H 9 was studied at 20°C in toluene and heptane. Maximum activity corresponds to the ratio Mg: Nd = 12-13 and the polymer contains 95% of 1,4-trans-units. At higher Mg: Nd ratios, the stereoregularity of polybutadiene deteriorates and is controlled by the nature of the solvent. It is suggested that trans-polybutadiene is produced by the catalytically active NdR 3 compounds formed by the reaction of the starting components of the catalytic system.

Abstract: The microdeformation behavior of the oriented fibers of polysulfonamide (PSA) was investigated by small-angle X-ray scattering (SAXS). The deformation of long periods during the elastic stretching is uniform and lags considerably behind the macroscopic deformation. Unusual reversible decrease in the SAXS reflection intensity is caused by decreasing crystallite density. The uncommon behavior of PSA on the level of long periods agrees well with an extremely low value of the elasticity modulus, previously observed in the PSA crystal lattice along the c axis (the fiber axis).

Abstract: A series of new polynaphthylimides was synthesized from diamines and bis(naphthalic anhydride)s of various structures by high-temperature polycyclocondensation. The solubility, heat resistance, and thermal stability of the resulting polymers, as well as the rheological properties of their melts, were studied. It was shown that the presence of hexafluoroisopropylidene groups in a diamine component and hinged groups in a dianhydride component markedly improves the solubility of polynaphthylimides and their processability by injection molding.

Abstract: The molecular weight of polyaniline samples, obtained by fractionated thermal vacuum deposition of an emeraldine base, was determined by cryoscopic method and the number of aniline units in the polymer chain was calculated. It is demonstrated that the second polyaniline fraction has a maximum molecular weight corresponding to 16 monomer units. The molecular weight determination is based on the data of X-ray photoelectron spectroscopy and can be performed either with or without an allowance for the presence of water in deposited polyaniline fractions.

Abstract: It was shown that the phase diagram for the blend of chlorinated polyethylene with the ethylenevinyl acetate copolymer in the presence of filler particles (silica gel) depends substantially on the order of mixing of the silica gel with the polymeric components of the blend. The amount of polymers that cannot be extracted by the solvent from off the silica gel surface and the ratio between soluble and insoluble fractions of the polymers were determined. The effect observed is explained by the change in the ratio between the energies of polymer adsorption on the silica gel surface when the order of the mixing of components is altered. A rule is proposed that permits one to control the thermodynamic stability of the polymer blend by adding a filler.

Abstract: A scheme of three-point bending deformation of a solid polymer sample, followed by measuring the rate of residual bending strain restoration in the course of a linear increase of the temperature of the mechanically polarized (deformed) sample was developed and implemented for studying the molecular mobility (mechanical relaxation) in solid polymers instead of the previously described variants of the thermostimulated creep (TSC) measurements. The proposed scheme requires no complicated device necessary for the conventional TSC measurements in polymers. The three-point bending TSC measurements were performed on a standard Perkin-Elmer TMS-2 thermomechanical analyzer. The new TSC method can be implemented with any device capable of measuring the linear thermal expansion of solids with sufficiently high sensitivity. Conditions providing the obtaining of high-quality TSC spectra are analyzed. The three-point bending TSC measurements were performed in several glassy polymers (PS, PMMA, PC, and a cross-linked epoxyamine polymer) in the temperature intervals from -180°C to T g . The bending-strain TSC modification allows the spectra of molecular motions, participating in the mechanical relaxation of polymeric glasses, to be obtained at a high sensitivity, resolution, and reproducibility. The TSC spectra of molecular motions in the polymers studied agree well with the data obtained by alternative methods. However, the bending-strain TSC provides a much better resolution compared to the other techniques. Joint application of the so-called fractionation methods (peak cleaning and partial heating procedures) provided data on the activation parameters of low-temperature molecular motions in all the polymers studied. The enthalpies of activation of the molecular motions obtained by the proposed method are close to the data available in the literature.

Abstract: Poly(3-hydroxybutyrate) membranes were studied by the method of small-angle X-ray scattering (SAXS) at various orientations of the samples with respect to the X-ray beam. An oriented long period with a Bragg distance of 6.1 nm, related to a predominant ordering of the crystallites along the normal to the membrane plane, was revealed. The function of orientation of the domains of ordered crystallites was analyzed using the azimuthal distribution of the SAXS reflection intensity. The values of the average crystallite thickness (4.4 nm), the intercrystallite amorphous layer thickness (1.8 nm), and the degree of crystallinity (70%) were determined. A correlation is established between the structural organization of membranes, characterized by the long period, and some important physicochemical properties of the membranes.

Abstract: The spectral-luminescence properties of solutions of zinc 5-(4-vinylphenyl)-10,15,20-triphenylporphyrin-methyl methacrylate copolymers with various content of porphyrin groups were studied. It was shown that a new long-wave band appears in the absorption spectra of the copolymers, the intensity of which depends on the copolymer composition, and the quantum yield of fluorescence decreases with increase in the molar fraction of porphyrin groups.

Abstract: Spontaneous radical polymerization of the complexes of vinylazoles with zinc dichloride in DMF was studied. The kinetic scheme of the process agrees with the bimolecular mechanism of initiation probably involving the biradicals, whose formation is favored by the reaction of the Zn 2+ ion with the π-system of vinylazole.

Abstract: Hydroxyl-containing oligoesters based on adipic acid and two diols (ethylene- and butylene glycols) were separated with respect to the number of end functional groups using liquid chromatography under critical conditions. For one of the homopolymers, poly(butyleneglycol adipate), the critical conditions, which correspond to the point of the coil-adsorbed coil transition, were attained by using Zorbax-NH 2 standard chromatographic columns and a hexane-methyl ethyl ketone binary solvent. The quantitative data on the relative content of non-, mono-, and bifunctional molecules in various commercial copolymers were obtained. Concurrently, homo- and copolymers (bifunctional with respect to OH groups) were separated under isocratic conditions.

Abstract: The IR spectra of PAN in bulk, solution, and gel state were recorded. It was found that upon precipitation, the PAN-DMAA system transforms into the gel state due to physical cross-linking. The crystal nature of the junctions of the gel network is evidenced by the presence of the IR absorption band at 780 cm -1 , which is characteristic of the crystalline phase of PAN.

Abstract: The effect of mechanical static and dynamic stresses on the structure of polyurethane elastomers was studied. The existence of the region of apparently safe stresses was established. In this region, an almost complete recovery of the mechanical modulus of the material was observed on unloading. A parameter of thermomechanical stability of three-dimensional physical network is suggested that allows one to estimate the safe stress level and to predict the fatigue properties of polyurethane elastomers.

Abstract: Phase diagram of the poly(y-benzyl-L-glutamate)-dimethylformamide (PBG-DMF) system in the entire range of concentrations was constructed using a combination of data available in the literature. A special role in the phase diagram belongs to the region of crystal solvate, which is analogous to the Luzzati complex phase. The proposed phase diagram of the PBG-DMF system exhibits a region of coexistence of the LC and crystal solvate phases instead of the region of two LC phases according to the well-known Flory diagram. The shape of the phase diagram generally coincides with the qualitative pattern proposed by Papkov for the solutions of rodlike molecules in the presence of a crystal solvate phase.

Abstract: The electrical and photovoltaic characteristics of a sandwich structure (Al/polymer/Se/SnO 2 + In 2 O 3 ) based on poly(hydroxyaminoester), photochemically oxidized by CBr 4 introduced in the polymer film, were studied. The oxidation product is an efficient sensitizer of photoconductivity in the red spectral range. This results in a four times higher efficiency of photoconversion in the visible light as compared to that of a photovoltaic cell with a polymer layer containing no oxidation products. The efficiency of photoconversion amounted to 0.05% at a wavelength of 630 nm and an illumination energy density of 0.45 W/m 2 .

Abstract: The effects of reaction medium and temperature on the size of nanoparticles of zero-valent nickel, formed by the reduction of divalent nickel ions in solutions of poly(N-vinylpyrrolidone), was studied. The average size of nickel particles was found to grow both on increasing the temperature during the reduction in water (from 4-7 nm at 20°C to 10-15 nm at 50°C) and upon replacement of water by a water-isopropanol 1:1 mixture (up to 5-20 nm at 20°C). The free energy, enthalpy and entropy of the polymer-particle interaction were calculated [at 20°C their values equal to -2.8 x 10 -4 J/m 2 , -2.5 x 10 -3 J/m 2 , and -7.4 x 10 -6 J/(m 2 K), respectively].

Abstract: A method for preparing soluble poly(p-chloromethylstyrene) by chloromethylation of linear PS with a methylal-thionyl chloride mixture was developed. The reactivity of the methylal-thionyl chloride mixture was shown to be governed by the molar ratio of methylal and thionyl chloride, while cross-linking was controlled by the ratio of PS to the chloromethylating mixture. It was shown by NMR spectroscopy that combining methylal and thionyl chloride led to chloromethyl methyl ether that reacted as a chloromethylating agent.

Abstract: A series of polynaphthylimides was synthesized, and the physicochemical and transport properties (gas permeability and diffusivity) of these polymers were investigated. The effect of the structure of dianhydride and diamine components on the properties of the resulting polymers was studied. It was shown that polynaphthylimides containing meta-substituted phenylene rings in a diamine component are characterized by lower gas permeability as compared to para-substituted polymers. The presence of condensed tetracyclic structure in a dianhydride component leads to polymers that show higher values of permeability and diffusion coefficients.

Abstract: New polymeric ligands with hetarylformazan groups were synthesized using anion exchangers. Physicochemical and sorption properties of the modified ion exchangers were studied. The ion exchangers were found to selectively extract copper and scandium ions from solutions containing accompanying elements.

Abstract: An increase in the stability of crystalline frameworks of clathrate hydrates, formed by three-dimensional ionogenic polymers based on tetrabutylammonium acrylate upon the introduction of help gases into the system, was observed. The melting temperature of the polyhydrate rises linearly with an increase in the gas concentration.