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Thermophysical and dielectric properties sequential semiinterpenetrating polymer networks (semi-IPNs) based on hydrophilic polyurethanes (PU), differing MM of oligomers, and natural polymers (gelatin, carboxymethyl cellulose) were investigated by methods DSC and DRC. It has been established, that with increase Mc initial PU networks the content of a linear component in compose of IPNs increases. The degree of crystallinity κpucmaππuɥʜocmu of PU-componenst in IPNs with gelatin and carboxymethyl cellulose increases. It was show, that introduction of natural linear polymers in sequential semi-IPNs influences on thermophysical characteristics and molecular mobility of the investigated polymeric systems depending on Mc initial PU networks . [ABSTRACT FROM AUTHOR]

The relaxation properties of polymer electrolytes based on block-copolymers PEO-PPO-PEO and LiClO4 were studied. It is shown, that the concentration dependence of relaxation times of conductivity has extreme character. The influence of free volume to process of ionic transport in polymer electrolytes PEO-PPO-PEO/LiClO4 is detected. It is shown, that such systems can be referred to "fragile". [ABSTRACT FROM AUTHOR]

The structure and dielectric properties of polymer electrolytes based on block- copolymers PEO-PPOPEO and inorganic salt LiClO4 were studied. It was shown, that at the ratio of Li/I = 1:8 and more polyelectrolytes based on three block copolymers PAO-PPO-PEO/LiClO4 are completely amorphous that results in growing of ionic conductivity in the systems of such type. [ABSTRACT FROM AUTHOR]

New polymeric adsorbents based on water soluble polysaccharide konjac glucomannan cross-linked with blocked alkyl- and aryl-, di- or polyisocyanate were synthesized and used for phenol adsorption from aqueous solutions. The interaction of polysaccharide with å-caprolactam blocked isocyanates was confirmed by pyrolysis mass-spectrometry. Glycopolymers based on cross-linked konjac glucomannan demonstrate good phenol sorption ability. To describe phenol adsorption on glycopolymers Langmuir and Freundlich models were used. The influence on phenol adsorption capacity of polysaccharide hydroxyl group substitution degree, isocyanate structure as well as pH value was analyzed. Adsorption equilibrium had been reached after 24 hours contact with phenol, nevertheless, 75–80% of phenol is adsorbed during first 6–8 hours. The highest phenol adsorption capacity onto GP had been reached at neutral medium whereas adsorption capacities at acid and alkali media are slightly lower. In contrast to glycopolymers based on aliphatic diisocyatate glycopolymers based on aromatic ones show higher adsorption capacity. This indicates the important role of π–π interactions between aromatic rings of adsorbate and polymeric matrix during adsorption. [ABSTRACT FROM AUTHOR]

A promising composite material is proposed to reduce the endogenous and exogenous contamination of chicken eggs with pathogenic microflora during their formation and storage. It is based on hybrid biocompatible and biodegradable silica/ polyacrylamide nanocarriers containing small silver nanoparticles (dav=2.4±1.0 nm) that are orally administered to laying hens with drinking water. The features of the formation of nanosilver in hybrid carriers by borohydride reduction of a silver salt at its various concentrations in an aqueous solution have been studied. An interesting effect of the sharp appearance of the second surface plasmon resonance band in the UV-Vis spectra of a silver salt/hybrid mixture at a high salt concentration was found. T is was explained by sharp structural changes in the hybrid carriers caused by the simultaneous growth of many AgNPs in them. It was assumed that the intensive growth of many AgNPs in one hybrid particle was accompanied by detachment of the grafted PAAm chains from the SiO2 surface due to the breaking of hydrogen bonds. The change in the state of the composite material under the influence of the pH of the solution, the concentration of nanoparticles, the presence of NaCl (as in a "physiological solution"), and visible light was studied by UV-Vis spectroscopy, potentiometric titration, and TEM. Nanosilver in carriers showed high stability with respect to most of these factors. The influence of the composite material on the clinical state of laying hens and important parameters of their eggs and blood was studied when it was administered orally with drinking water three times every 10 days at doses of 0.2 and 0.4 mg per chicken per day. A striking effect of selective endogenous accumulation of silver in eggshells has been revealed. This confirmed the penetration of the nanosilver composite into the circulatory system of chickens by passing through the digestive tract, absorption through the intestinal epithelium and further transport into the tissues of the chickens, including the oviducts, where protein and eggshell are formed. Such penetration did not cause a toxic effect on the body of laying hens. [ABSTRACT FROM AUTHOR]

It has been studied electrical and optical properties of the systems based on the polypropylene glycol and carbon nanotubes by impedance spectroscopy and spectrophotometry methods. It is shown that conductivity grows and optical permeability decreases with nanotubes content at the system according to the percolation behavior. The concentration dependences of the conductivity and optical permeability have been analyzed within scaling approach. It is shown that optical percolation threshold for this system equals 0,01%. The experimental results have described within critical percolation model. [ABSTRACT FROM AUTHOR]

By method of impedance spectroscopy the dielectric properties of polypropylene glycol with Mw=400 (PPG-400) and carbon nanotubes(CNT) in percolation transition field were investigated. At the defined concentration CNT ~0.45% in the PPG-400/CNT system the percolation threshold was observed and both sharp change of electrical conductance and α-relaxation time was appeared. [ABSTRACT FROM AUTHOR]

Structure and conductivity of systems based on polyethyleneglycol (PEG), LiClO4 and anisometric nanofillers in bulk and thin films were studied using X-ray scattering and dielectric relaxation spectroscopy methods. It was shown, that structure of the systems based on PEG, substantially depend on the content of the nanofiller and the type of the plate, where the film was formed. It is discovered that the relative degree of crystallinity of PEG/LiClO4 has extreme behavior, which is dependent on the content of the nanofiller. [ABSTRACT FROM AUTHOR]

The relaxation processes and conductivity of organic-inorganic systems based on polyethylene glycol and polyhedral silsesquioxane (POSS) were studied using dielectric relaxation spectroscopy. It is shown that the levels of conductivity of the systems based on POSS substantially depend on the amount of ion groups and content of inorganic phase. It is discovered that conductivity of direct current has extreme dependence on composition of organic-inorganic hybrid systems based on POSS. The structure was studied by small angle x-ray scattering. The results of x-ray scattering were analyzed using classical and fractal formalism. The structure of organic-inorganic nanocomposites based on POSS has the extremal nature. [ABSTRACT FROM AUTHOR]

A graft copolymer of poly(vinyl alcohol) and polyacrylamide (PVA-g-PAAm) with interacting main and graft ed chains was synthesized by radical matrix polymerization of PAAm from the PVA backbone in an aqueous medium. Its basic molecular parameters including the number and length (molecular weight) of graft s were determined using elemental analysis, DTGA and viscometry. The copolymer macromolecules formed special monomolecular micelles of elipsoidal shape and length ~18-64 nm in aqueous solutions due to the formation of intramolecular polycomplexes between the main and graft ed chains. This copolymer was used as a hydrophilic matrix for the in situ synthesis of nickel nanoparticles (NiNPs) in aqueous solutions. On the basis of UV-Vis spectroscopy, an original and simple method for monitoring the kinetics of the formation and yield of metal nanoparticles in systems in which a surface plasmon resonance band does not appear has been proposed and implemented. Using this approach, the kinetics of borohydride reduction of Ni-salt to NiNPs in pure water and PVA-g-PAAm solutions was studied depending on the concentrations of Ni-salt and copolymer matrices. An increase in the initial rate of accumulation and yield of NiNPs with an increase in the concentration of Ni-salt and a decrease in both parameters in copolymer solutions in comparison with pure water was established. At the same time, the accumulation rate and NiNP yield in a complex way was depended on the matrix concentration that was determined by the ratio of such factors as a decrease in the diffusion rate of NaBH4 molecules in copolymer solutions and the accumulation of Ni2+-ions in matrix particles due to complexation with active chemical groups at the first stage of reduction process. The morphology and main structural elements of the NiNPs/PVA-g-PAAm composition were revealed using TEM. It was shown that the in situ synthesis of NiNPs in copolymer matrices was accompanied by the "detachment" of PAAm graft s from the main PVA chains and led to the appearance of two new structures, such as "hairy coils" and "hairy rods", containing small spherical NiNPs (d~0,5-12,0 nm) in isolated and chain states, respectively. The appearance of the latter structures was explained by the formation of coordination complexes of Ni2+-ions with active groups of both PVA and PAAm chains at the first stage of the reduction reaction. [ABSTRACT FROM AUTHOR]

The differential scanning calorimetry method was used to investigate the kinetics of thermal dissociation of є-caprolactame blocked polyisocyanate under non-isothermal conditions using isoconversion approach. The values of kinetic parameters of the process calculated using several theoretical models (Kissinger, Ozawa--Flynn--Wall, Friedman) are in good agreement. Differential scanning calorimetry with temperature modulation denotes the structural changes in the system under heating and consumption of considerable part of NCO-groups at the same time with thermal dissociation. [ABSTRACT FROM AUTHOR]

The influence of the multiprotons phosphoric and citric acids ratio on the heat resistance of epoxy compositions was investigated. It was found, that the grafting of individual acids leads to decreasing of the thermal stability of the cured compositions. While combining mineral and carboxylic acids markedly reduces this effect. Increasing of the citric acid amount and corresponding reduction of phosphoric acid amount in combined modifier leads to increased thermal stability of the systems. [ABSTRACT FROM AUTHOR]

Structure research of hybrid organic-neorganic composites based on polyimide and tetraethoxysilane by x-ray scattering has shown that at introduction of the minimum quantity of an inorganic component contrast of the spatially-ordered structure of polyimide matrix increases. At the further increase in the content of an inorganic component the violation of the smallangle periodicity and formation of anizodiametric inclusions enriched with SiO2 is observed. [ABSTRACT FROM AUTHOR]

The molecular mobility was analyzed in organic-inorganic composites based on polyimide with card substituents using EPR spectroscopy with nitroxyl paramagnetic probe TEMPO. According to data obtained introduction of tetraethoxysilane into polyimide with card substituents in all cases is accompanied with decreasing of inhomogeneity of the polyimide component in composite. The reducing of correlation time value is observed with temperature growth due to polymer mobility rise as well as fast recovering of initial state of thermo cured polyimide after cooling. [ABSTRACT FROM AUTHOR]

Structural features have been studied of epoxy compositions with grafted bibasic carbonic acids. The maximum structural changes as compared with initial oligomer occur in epoxy composition with citric acid, and the minimal structural changes occur in composition with oxalic acid. The decreasing of intensity of crystal reflexes typical to carbonic acids relates to partial amorphization of acid molecules as a result of covalent binding between acid and epoxy functional groups. [ABSTRACT FROM AUTHOR]

Structure and percolative properties of composites based on polyvinyliden fluoride (PVDF) and its mixtures with polyaniline (PANI), doped with p-toluenesulfonic acid (TSA) was investigated by the methods of X-ray analysis, differential scanning calorimetry and impedance spectroscopy. It was shown, that descriptions of such compositions substantially depend on content of PANI-TSA and on the method of their preparation. It was established, that systems PVDF-PANI-TSA show a percolation behavior with low percolation threshold Cc H" 4%. The decrease of the crystallinity of PVDF-PANI-TSA systems specifies the mobility decrease of polymer chains of PVDF in the boundary layer around particles PANI-TSA. The investigated system is incompatible, that results in a segregation PANI-TSA in a separate phase. [ABSTRACT FROM AUTHOR]

The influence of the copper (2+) chelate quantity on the thermo physic properties and thermo stability of the modified metal containing cross-linked polyurethanes is explored. It was determine, that there is the tendency to increasing of the glass temperature and the enlargement of the interval of glassing, and also noticeable growth of the heart capacity and heterogeneity level of the system with the increasing of the coordination modifier quantity in polyurethane from 0,5 to 5,0 % wg. The activating parameters for the stages of the intensive thermo oxidation destruction of the metal containing cross-linked polyurethanes correlate with the quantity of the metal compound, which entered in the polymer. [ABSTRACT FROM AUTHOR]

Polyimide nanocomposites were synthesized by in situ polymerization using 4,4'- diaminodiphenylmethane, pyromellitic dianhydride, carbon nanotubes. The structure of polyimide nanocomposites were studied using SAXS method. It was established reversibility of contrast structure at contents of CNT above percolation threshold. [ABSTRACT FROM AUTHOR]

Attempt is made to strengthening carbon frame nanostructured carbon materials (NVM), obtained by template, additional processing of its internal porous space. Established that the strengthened carbon frame NVM leads to virtually complete elimination of micropores and increased mechanical strength of the material. Method of small angles X-ray scattering features the evolution of short-range ordering and porosity of nanopore carbon adsorbents obtained with a template synthesis method at all intermediate stages carbon retorts forming, and also their derivatives with strengthened frame. [ABSTRACT FROM AUTHOR]

Structure and thermal properties of systems based on olygoethyleneglycol and anisometric nanofillers were studied using X-ray scattering and DSC methods. It is shown that structure and thermal properties of the systems based on OEG substantially depend on the nature and content of nanofiller. It is discovered that thermal characteristics has extreme behavior, which is dependent on composition of systems based on OEG. [ABSTRACT FROM AUTHOR]

The relaxation processes and conductivity of polymer electrolytes based on oligoethyleneglycol (OEG) and anisometric nanofillers were studied using dielectric relaxation spectroscopy. It is shown that the levels of conductivity of the systems based on OEG substantially depend on the nature and content of nanofiller. It is discovered that conductivity of direct current has extreme dependence on composition of polymer electrolytes based on OEG. [ABSTRACT FROM AUTHOR]

In this work are shown results of synthesis and properties investigation of film ionogenic materials based on sulfonated derivates of polyamides, which modified by nonorganic nanosides particles of zirconium phosphate (ZrP). Composite materials include by themselves 5-10 % of ZrP, and they gain high ionic exchange capacity (3,13-4,30 meq/g) and thermal stability until 220 ϵC. Based on data of XRD analysis established that the initial sulfonated polyamides and composite materials on their basis are amorphous systems witch contained on themselves quasicrystaline domains. A method of filling by inorganic particles was proposed for obtaining a new composite materials. Established that the inorganic filler equispaced in amorphous and quasicrystalline phase and filler have a size of particles in interval from 1-2 to 300 nm. [ABSTRACT FROM AUTHOR]

With the purpose of parameters optimization of the polymeric materials which are perspective for use in various electrochemical devices, researches of interconnection of internal structure and ionic conductivity of membranes based on cross-linked ammonium interpolymers or copolymers of epichlorohydrin with ethylene oxide and poly-4-vinylpyridine. It was established, that AIPC are characterized by a amorphous type of near-field region ordering, and also partial fractal aggregation, features of which can influence on the ions transportation in volume of a polymeric matrix. Ionic conductivity of ammonium interpolymeric c0mplexes activated by orthophosphoric acid and in additional humidified in water is 5.5·10-3 Ohm-1 cm-1 temperature. [ABSTRACT FROM AUTHOR]

The inner surface of high porosity nanocarbon materials that obtained by templated synthesis on the inorganic molecular sieve and high pyrolysis yield polymers base was used as support for catalytic active Ni nanoclusters. The structure peculiarities of templated nanoporous carbon material with nickel nanoclusters that formed in carbon pores were studied by small-angle X-ray (SAXS) scattering methods. The catalytic activity of Ni nanoclusters supported by nanostructured carbon membranes in processes of cathodic reduction of hydrated protons and hydrocracking of alkylaromatic hydrocarbons was investigated. It was established that dendritic shape aggregates of Ni nanoclusters that grew on the inner surface of carbon pores showed maximum catalytic activity in both reactions. [ABSTRACT FROM AUTHOR]

The relaxation processes and conductivity of organic-inorganic systems based on polypropylene glycol and polyhedral silsesquioxane (POSS) were studied using dielectric relaxation spectroscopy. It is shown that the levels of conductivity of the systems based on POSS substantially depend on the amount of ion groups and content of inorganic phase. It is discovered that conductivity of direct current has extreme dependence on composition of organic-inorganic hybrid systems based on POSS. [ABSTRACT FROM AUTHOR]

Structural features of nanocomposites formation on a basis epoxid oligomer ED-20 at presence highdisperce aeroforce with the different nature of a surface (A-300, AM-300) are investigated. It is shown, that filler is characterized by two-level character of structure. The first - units of particles aeroforce in the sizes about 30 nanometers with the rough surface make superficially - fractal, the second - massfractal units of the big sizes (> 500 nanometers) which will consist of units of the first level. At introduction such filler in a epoxid matrix observable character of his(its) spatial aggregation appreciably is kept, but reduction of filler contents is accompanied sinbatic by reduction of the sizes superficially - fractal units of the first level. Mechanical characteristics of nanocomposites are defined(determined) by features of the structural organization of a material and depend on the maintenance(contents) aeroforce and the nature of his(its) surface. [ABSTRACT FROM AUTHOR]