Institute of Macromolecular Chemical NAS of Ukraine

Kiev, Ukraine

Institute of Macromolecular Chemical NAS of Ukraine

Kiev, Ukraine
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Bezrodnyi V.I.,Ukrainian Academy of Sciences | Negryiko A.M.,Ukrainian Academy of Sciences | Ishchenko A.A.,Institute of Organic Chemistry NAS of Ukraine | Kosyanchuk L.F.,Institute of Macromolecular Chemical NAS of Ukraine
Proceedings of the International Conference on Advanced Optoelectronics and Lasers, CAOL | Year: 2016

Effects of polyurethane matrix polarity on the spectral, nonlinear-optic and switching properties of thiopyrilo-4-tricarbocyanine phototropic dye were studied. The experimental results of passive Q-switching for the neodymium laser by Q-switches based on aliphatic polyurethane of high dielectric permittivity were presented. Positive influence of polymer matrix polarity on high-efficient generation of powerful single pulses was shown. © 2016 IEEE.


Myshak V.,Institute of Macromolecular Chemical NAS of Ukraine | Seminog V.,Institute of Macromolecular Chemical NAS of Ukraine | Dmytrieva T.,Institute of Macromolecular Chemical NAS of Ukraine | Bortnitsky V.,Institute of Macromolecular Chemical NAS of Ukraine
Chemistry and Chemical Technology | Year: 2016

Pyrolysis mass-spectrometry (PMS) has been employed to investigate the process of thermal destruction of the secondary polyethylene (SPE), which was modified using hexamethylenetetramine (HMTA). The introduction of powdered HMTA in the polymer matrix on the basis of SPE, with a view to its mechano-chemical modification, leads to structural changes in the polymer matrix, to the formation of cross chemical bonds between macromolecules in SPE with the participation of the ionic fragments of the collapse of HMTA, and to high content of gel-fraction of compositions with increasing of HMTA content in them. © 2016. Chemistry & Chemical Technology. All rights reserved.


Lysenkov E.A.,khomlynskyi Mykolayiv National University | Klepko V.V.,Institute of Macromolecular Chemical NAS of Ukraine
Journal of Physical Studies | Year: 2016

The purpose of this work was to study the percolation phenomenon in the nanofilled systems from the fundamental point of view, using the scaling approach. The conductivity of the systems based on polyethers (polyethylene glycol, polypropylene glycol and polytetrehydrofuran) and carbon nanotubes is investigated using the method of impedance spectroscopy and analysed in the frame of the percolation theory. It is discovered that the dependence of conductivity of investigated systems shows percolation behavior. It is shown that the percolation threshold, which was observed in the range of the CNT content from 0.3% to 0.5%, for the probed systems depends on the type of the polymeric matrix. The value of percolation thresholds is determinated using the alternative Chodak-Krupa approach and the theory of excluded volume. It has been established that the crystallinity of the polymeric matrix considerably influences the value of the percolation threshold. The percolation threshold is inversely proportional to the matrix crystallinity. The critical indices of conductivity (t and s) were certain using the scaling approach. The value of the critical index t varies in the range from 1.15 (for liquid polypropylene glycol) to 1.88 (for crystalline polyethylene oxide). It is discovered that the processes of a filler’s aggregation, its high aspect ratio, and high conductivity of neat polymer matrix tend to play leading roles in the formation of a conductive percolation network. © 2016, Ivan Franko National University of Lviv. All Rights Reserved.


Lysenkov E.,Vo Sukhomlynskyi Mykolayiv National University | Melnyk I.,Taras Shevchenko National University | Bulavin L.,Taras Shevchenko National University | Klepko V.,Institute of Macromolecular Chemical NAS of Ukraine | Lebovka N.,Biocolloidal Chemistry Institute Named After F D
Springer Proceedings in Physics | Year: 2015

The structure of polyglycols (polyethylene glycol and polypropylene glycol) doped by nanoparticles with anisotropic shape (carbon nanotubes and inorganic nanoplatelets) is discussed. Various experimental methods such as X-ray scattering, optical microscopy, impedance spectroscopy, differential scanning calorimetry and electrical conductivity measurements have been used. Introduction of such nanoparticles results in noticeable changes in the polymer structure even at rather small concentration of fillers (0.3–0.5 wt%). The percolation behaviour is typical for fluid and semicrystalline polyglycols doped with carbon nanotubes. In the vicinity of percolation threshold the entangled network of nanotubes is formed. This network has impact on the kinetics of polymer crystallization, degree of crystallinity, electrical and thermal properties of the composites. Different types of electrical conductivity in these systems were identified. The structure of polyglycols doped with nanoplatelets depends upon the type of the filler. The data evidence the presence of partial intercalation of macromolecules inside the interlayer space of nanoplatelets of organo-modified montmorillonite and the complete exfoliation oforgano-modified laponite platelets inside the polymer matrix. The doping by nanoplatelets also improved the dispersion of nanotubes inside polyglycols. The effects of nanofillers on the behaviour of polymer electrolytes on the base of polyglycols are also discussed. The doping allows decreasing the degree of ionic association, resulting in higher concentration of the free ions and increased electrical conductivity. © Springer International Publishing Switzerland 2015.


Lysenkov E.A.,Mykolayiv National University Named After Vosukhomlynskiy | Klepko V.V.,Institute of Macromolecular Chemical NAS of Ukraine
Journal of Nano- and Electronic Physics | Year: 2016

The basic theoretical models of electrical conductivity of polymer nanocomposites and their accordance to experimental results are analysed for the systems based on polyethers and carbon nanotubes using the methods of mathematical simulation. It is set that models which are based on the effective medium approximation do not take into account existence of percolation threshold and can't be using for exact definition of experimental data. It is discovered that the Fourier model demonstrats a good accordance with an experiment, however it is applicable only for the systems in which a large increase of conductivity under reaching the percolation threshold is observed, that systems with low own conductivity. It is set that the best accordance to experimental data was shown by the Kirkpatrick model and the generalized McLachlan model, which, except for the percolation threshold, structural descriptions of clusters which are formed from carbon nanotubes take into account. © 2016 Sumy State University.


Bezrodnyi V.I.,Ukrainian Academy of Sciences | Negryiko A.M.,Ukrainian Academy of Sciences | Klishevich G.V.,Ukrainian Academy of Sciences | Stratilat M.S.,Institute of Macromolecular Chemical NAS of Ukraine | And 2 more authors.
Journal of Polymer Research | Year: 2013

A new polymer matrix based on aliphatic polyurethane was proposed and investigated for the development of laser active media for the tunable dye lasers. The polymer matrix was synthesized by the prepolymer method. The prepolymer, obtained from hexamethylene diisocyanate and oligodiethyleneglycol adipinate, was hardened by trimethylolpropane. The production method of the laser sandwich-like active media based on xanthene and pyrromethene dyes was described; their spectral, photophysical and generation characteristics were investigated. Significant increase in the beam strength of the polymer matrix, the growth in efficiency and stability of the active elements are observed due to the peculiarities of aliphatic polyurethane chemical structure. The main reason for the high photostability and operation lifetime of laser polyurethane-based active elements was shown to be the absence of reactive radicals. © 2013 Springer Science+Business Media.


Kosyanchuk L.,Institute of Macromolecular Chemical NAS of Ukraine | Bezrodna T.,Ukrainian Academy of Sciences | Stratilat M.,Institute of Macromolecular Chemical NAS of Ukraine | Menzheres G.,Institute of Macromolecular Chemical NAS of Ukraine | And 2 more authors.
Journal of Polymer Research | Year: 2014

Possibility for chemical interactions of 6-aminophenalenone dye with the components of reaction mixture at the polyurethane formation was shown by means of X-ray wide angle scattering, EPR and visible spectroscopy methods. This was also confirmed by IR-spectroscopy, identifying the products of the model reaction between 6-aminophenalenone and hexamethylene diisocyanate. Observed large Stokes shift gives prospects to use efficiently the polyurethane matrix with 6-aminophenalenone as an active element in dye lasers. © 2014, Springer Science+Business Media Dordrecht.


Lysenkov E.A.,Mykolayiv National University Named After Vosukhomlynskiy | Klepko V.V.,Institute of Macromolecular Chemical NAS of Ukraine | Yakovlev Y.V.,Institute of Macromolecular Chemical NAS of Ukraine
Journal of Nano- and Electronic Physics | Year: 2015

The research of electric properties of the systems based on polyethylene glycol and carbon nanotubes (CNT) near-by the percolation threshold is done using the method of impedance spectroscopy. It is set that the percolation threshold for these systems substantially depends on the sizes of nanotubes. It is discovered that with the increase in the CNT diameter, the percolation threshold is increased. The dispersion parameters of nanotubes were calculated using theoretical model. The results of calculations and microphotographs testify to the high level of CNT{cyrillic} aggregates in the polymer nanocomposites based on polyethylene glycol. © 2015 Sumy State University.


Bezrodna T.V.,Ukrainian Academy of Sciences | Kosyanchuk L.F.,Institute of Macromolecular Chemical NAS of Ukraine | Negryiko A.M.,Ukrainian Academy of Sciences | Stratilat M.S.,Institute of Macromolecular Chemical NAS of Ukraine | Todosiichuk T.T.,Institute of Macromolecular Chemical NAS of Ukraine
Proceedings of the International Conference on Advanced Optoelectronics and Lasers, CAOL | Year: 2013

A new polymer matrix based on aliphatic polyurethane was proposed and investigated for the development of laser active media for the tunable dye lasers. The production method of the laser active media based on xanthene and pyrromethene dyes was described; their spectral, photophysical and generation characteristics were investigated. The main reason for the high photostability and operation lifetime of laser polyurethane-based active elements was shown to be the absence of reactive radicals. © 2013 IEEE.


Lysenkov E.A.,Mykolayiv National University Named After Vosukhomlynskiy | Klepko V.V.,Institute of Macromolecular Chemical NAS of Ukraine
Journal of Nano- and Electronic Physics | Year: 2013

The research of the electrical properties of the systems based on polyethylene glycol and carbon nanotubes near-by the percolation threshold is done using the method of impedance spectroscopy. It is established that the percolation threshold for these systems is 0,5%, and critical index t = 1,17. It is discovered that non-conducting polymeric film appears between separate nanotubes. The thickness of the film which is 7-8 Å and its contact resistance which is 3·105 Ohm were derived using theoretical models. This explains a difference in conductivity of pure nanotubes and probed system after the percolation threshold. © 2013.

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