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101 results on '"Sergeeva, L. M."'

8. Thermoplastic Apparent Interpenetrating Polymer Networks of Polyurethane and Styrene/Acrylic Acid Copolymer Obtained by Melt Mixing. Structure-Properly Relationships

Author

VATALIS, A. S., DELIDES, C. G., GRIGORYEVA, O. P., SERGEEVA, L. M., BROVKO, A. A., ZIMICH, O. N., SHTOMPEL, V. I., GEORGOUSSIS, G., and PISSIS, P.

Subjects
Thermoplastics -- Mixing, Crystalline polymers -- Production management, Engineering and manufacturing industries, Science and technology, Production management
Abstract

Thermoplastic apparent interpenetrating polymer networks (thermoplastic-AIPNs) were prepared at several compositions by melting and pressing of crystallizable polyurethane (CPU), based on butylene adipate glycol (BAG), and styrene/acrylic acid random copolymer [...]

Published
2000

31. Molecularly-imprinted polymers for the development of new analytical methods. Molecularly-imprinted polymer membranes.

Author

Sergeyeva, T. A., Sergeeva, L. M., and Brovko, O. O.

Subjects
*IMPRINTED polymers, *POLYMERS, *MACROMOLECULES, *MOLECULAR imprinting, *POLYMERIZATION, *CHEMICAL reactions
Abstract

The review is devoted to analysis of the publications in the area of synthesis of polymeric membranes according to the technique of molecular imprinting as well as investigation of their properties. Different types of the molecularly-imprinted polymer membranes are described and the main techniques for their synthesis are analyzed. The review is also concentrated on the application of the molecularly imprinted polymer membranes for the development of new analytical methods. [ABSTRACT FROM AUTHOR]

Published
2009

32. Dielectric Study of Relaxation Behaviour of semi-Interpenetrating Polymer Networks based on Polyurethane and Poly(2-hydroxyethyl methacrylate).

Author

Karabanova, L. V., Sergeeva, L. M., Svyatyna, A. V., Seytre, G., Boiteux, G., and Stevenson, I.

Subjects
*RESEARCH, *PHYSICAL & theoretical chemistry, *POLYMER networks, *PHOTOPOLYMERIZATION, *SPECTRUM analysis
Abstract

The study of dielectric properties and molecular dynamics in Polyurethane (PU), Poly(hydroxyethyl methacrylate) (PHEMA) and in semi-IPNs based on PU and PHEMA synthesized by photopolymerization are presented. The results of broadband dielectric spectroscopy (BDS) investigation are compared with results of investigation by dynamic mechanical analysis(DMA) with the goal to have a better insight on the dynamic of the chain and their relation with the structure. The relaxation maps for investigated PU, PHEMA and semi-IPNs were built. [ABSTRACT FROM AUTHOR]

Published
2007

35. In Situ Formation of Porous Molecularly Imprinted Polymer Membranes

Author

Sergeyeva, T. A., Piletsky, S. A., Piletska, E. V., Brovko, O. O., Karabanova, L. V., Sergeeva, L. M., El'skaya, A. V., and Turner, A. P. F.

Abstract

Molecularly imprinted polymer membranes for a model compound, atrazine, were prepared in situ from a monomer mixture containing methacrylic acid, tri(ethylene glycol) dimethacrylate, and atrazine using UV-initiated polymerization. To improve flexibility and mechanical stability of these membranes, oligourethane acrylate was added to the mixture of monomers. Polymeric additives were used to increase porosity of membranes and their permeability as well as to make them suited for filtration experiments. This process resulted in the formation of thin, flexible, and porous membranes containing atrazine-specific binding sites. The atrazine-imprinted membranes showed higher affinity to this herbicide than to structurally similar compounds (simazine, prometryn, and metribuzin). The binding capacity of MIP membranes was found to be significantly higher than that observed previously for MIP systems. The high affinity, specificity, and binding capacity of MIP membranes, together with their straightforward and easy preparation, provide a good basis for their application in separation and purification, e.g., in membrane chromatography.

Published
2003

36. Structure–property relationships in thermoplastic-apparent interpenetrating polymer networks based on crystallizable polyurethane and styrene–acrylic acid copolymer

Author

Kyritsis, A., Pissis, P., Grigorieva, O. P., Sergeeva, L. M., Brouko, A. A., Zimich, O. N., Privalko, E. G., Shtompel, V. I., and Privalko, V. P.

Abstract

Structure–property relationships in thermoplastic-apparent interpenetrating polymer networks (t-AIPNs), prepared by mechanical blending in a common solvent of crystallizable polyurethane (CPU) and styrene/acrylic acid random copolymer (S/AA), were investigated by means of wide-angle and small-angle X-ray scattering (WAXS and SAXS), dynamic mechanical analysis (DMA), thermally stimulated depolarization currents (TSDC) techniques, dielectric relaxation spectroscopy (DRS), and density, water uptake, deformation, and strength characteristics measurements. Several mechanical and dielectric relaxations of the pure components were characterized, and the effects thereupon induced by blending were followed. The two components show weak affinity to each other. The t-AIPNs can be classified into two groups with high and low contents of CPU, showing essentially the behavior of CPU and of S/AA, respectively. On the other hand, deviations from additivity in several properties indicate interactions between the two components, caused by the formation of H-bonds between their functional groups, and resulting in partial miscibility. In addition, significant changes are observed on some properties of the t-AIPNs on addition of small amounts of either of the components. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 385–397, 1999

Published
1999
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47. Rubbing-surface phenomena for the case of an MoS2-steel friction pair

Author

Sergeeva, L. M., Vainshtein, V. E., Gluskin, Ya. A., and Memelov, V. L.

Abstract

Profilograph measurements and microscopic examination were used to study the wear of the working surfaces of an MoS2-steel 2Kh13 friction pair in air and in a vacuum. Blistering of the MoS2 films during friction tests in air was observed and the possible causes of this phenomenon were postulated.

Published
1971
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48. Impact Scale Factor on Adhesion and Viscoelastic Behaviour of Epoxy Networks in Adhesive Connections.

Author

Tkalich, M. G., Gorbach, L. A., Sergeeva, L. M., and Brovko, O. O.

Subjects
*VISCOELASTICITY, *ADHESION, *EPOXY resins, *CHEMICAL decomposition, *POLYMERS, *SUBSTRATES (Materials science)
Abstract

Investigation of a scale factor effect on adhesion and viscoelastic properties of adhesive based on epoxy resin curried with polyamine was carried out. By using dynamic mechanical analysis method the viscoelastic behavior of both free epoxy films and adhesive joints in whole was studied. The sickness of adhesive layer and free films as a scale factor was varied in interval of 50-900 mkm. The increase of epoxy adhesive layer thickness was shown to result in the nonmonotonic decrease in an adhesive strength value. The dramatic drop of adhesion strength was observed for adhesive layers having thickness less 200 mkm and more slowly degradation occurred in case of thicker ones. Along with this the correlation between adhesive layer thickness and polymer ability to dissipate mechanic energy took place. It was also shown that layer thickness influenced not only adhesion and viscoelastic behaviors of adhesive but coupled with the effect of substrate (duralumin) surface caused the changes in topology and morphology of epoxy networks. Particularly the appearance of shoulder associated with additional relaxation transition on the rising wing of the maximum at loss module temperature dependence for sample of adhesion joint with adhesive layer of 800 mkm indicated the fluctuation of cross-linking density of epoxy network. [ABSTRACT FROM AUTHOR]

Published
2013

49. Viscoelastic Properties and Formation Simulation of Polyurethane-Polyacrylate Gradient Interpenetration Polymer Networks.

Author

Brovko, O. O., Gorbach, L. A., and Sergeeva, L. M.

Subjects
*POLYMER networks, *VISCOELASTICITY, *ANISOTROPY, *ACRYLATES, *GLASS transition temperature, *CHEMICAL properties, *IMITATIVE behavior, *CRYSTALLOGRAPHY
Abstract

Viscoelastic properties both traditional and gradient polyurethane-polyacrylate IPNs were studied. Both types of IPNs were shown to be two-phase systems inclusive considerable interphase area. It was found that GIPNs were characterized by anisotropy of viscoelastic properties specified by different structure depending on the direction of concentration gradient of acrylate component and which possessed a broad glass transition interval that defined an ability of material to dissipate the mechanical energy. By using the model imitation method the system of questions describing the GIPN formation kinetic - gradient profile generation was proposed. Property-composition correlation dependences were found that allow one to realize the transfer from concentration gradient profiles to those of distribution of properties, in particular elastic modulus, within GIPN layers. [ABSTRACT FROM AUTHOR]

Published
2009

50. Peculiarities of formation and properties of organic - inorganic systems based on sodium silicate.

Author

Brovko, O. O., Gorbach, L. A., Lutsyk, O. D., Sergeeva, L. M., and Lebedev, E. V.

Subjects
*ORGANIC compounds, *SOLUBLE glass, *INORGANIC synthesis, *CHEMICAL structure, *ISOCYANATES, *COMPOSITE structures
Abstract

Sodium silicate and diisocyanate based organic-inorganic systems were synthesized. Their formation, structure, and properties were studied by means of IR-spectroscopy, DMA, TGA, and transmission optical microscopy. During structuring of organic-inorganic composite obtained the isocyanate groups cyclotrimerization was found to take place simultaneously with urea-urethanes formation reaction. It was shown that the formation of isocyanurate cycles in composite structure resulted in emergence of additional relaxation transition in temperature dependences of viscoelastic functions. [ABSTRACT FROM AUTHOR]

Published
2013

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