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Papers by Omar Mukbaniani

Research paper thumbnail of Block-copolymers with Polyphenyl-α-Naphtylsilane Fragments in Dimethylsiloxane Chain

International Journal of Polymeric Materials, 2001

ABSTRACT The Wurtz-type reductive-coupling reaction of dichlorophenyl-α-naphtylsilanes was carrie... more ABSTRACT The Wurtz-type reductive-coupling reaction of dichlorophenyl-α-naphtylsilanes was carried out both in the presence of metalic sodium in toluene solution and in a mixture of toluene and o-xylene (at 1:1 ratio) in the presence of sodium and catalytic amount of mercury. Oligomers of α,ω-dichlorophenyl-α-naphtylsilane with various degrees of polymerization were obtained. By hydrolysis of α,ω-dichlorophenyl-α-naphtylsilane the corresponding α,ω-dihydroxydiorganosilanes has been obtained. The heterofunctional condensation of α,ω-dichloro(dihydroxy)phenyl-α-naphtylsilanes with α,ω-dihydroxy(dichloro)dimethylsiloxanes in the presence of acceptor pyridine has been carried out and polysilane-siloxane block-copolymers were obtained. Depending on the lengths of the rigid and flexible initial oligomers microdomain structure of block-copolymers were observed. The synthesized block-copolymers were characterized by gel permeation chromatography, differential scanning calorimetry and X-ray methods.

Research paper thumbnail of Synthesis and characterization of poly (siloxane‐urethane) s

Polymer International, 1992

A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and po... more A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and poly (propylene glycol) soft segments of molecular weights 1818 and 2000, respectively, were synthesized. The hard segments consisted of 4, 4′- ...

Research paper thumbnail of Solid Polymer Electrolyte Membranes on the Basis of Fluorosiloxane Matrix

Chemistry and Chemical Technology, 2021

Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with ... more Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with 2,2,3,3,4,4,5,5-octafluoropentyl acrylate at 1:4.2 ratio of initial compounds catalysed by platinum catalysts have been studied and corresponding adduct D4R' has been obtained. Ring opening polymerization of D4R in the presence of dry potassium hydroxide has been carried out and comb-type polymers with 2,2,3,3,4,4,5,5-octafluoropentyl propionate side groups have been obtained. The synthesized product D4R and polymers were analyzed by FTIR, 1H, 13C, and 29Si NMR spectroscopy. The solid polymer electrolyte membranes have been obtained via sol-gel reactions of polymers with tetraethoxysilane doped with lithium trifluoromethylsulfonate (triflat) and lithium bis(trifluorosulfonyl)imide. It has been found that the electric conductivity of the polymer electrolyte membranes at room temperature changes in the range of (1.9•10-6) – (5.9•10-10) S•cm-1.

Research paper thumbnail of Synthesis and Investigation of Properties of Comb-Type Methylsiloxane Copolymers with Pendant Diphenylsiloxane Groups

Advanced Materials, Polymers, and Composites

Research paper thumbnail of Sawdust based composites

Polymers for Advanced Technologies

Research paper thumbnail of Electric Conductivity of Polymer Composites at Mechanical Relaxation

Chemistry & Chemical Technology

Effect of mechanical relaxations on the relaxation phenomena of electrical conducting polymer com... more Effect of mechanical relaxations on the relaxation phenomena of electrical conducting polymer composites (ECPC) has been investigated. It has been experimentally shown that filler content significantly affects relaxation characteristics of the material. The main reason of these differences is the effect of the filler type on proceeding of relaxation processes. Rubbers with active carbon blacks display the ranges of slow and fast relaxations much more clearly than those with low active carbon black. The effect of the filler type is displayed by formation of an interphase layer and is similar to the effect of the filling degree. In the case of active carbon blacks, the increase of the fillerfiller and polymer-filler interactions is balanced by a high content of low active carbon blacks, since in both cases the modules of the material and internal friction grow.

Research paper thumbnail of Polymer-Silicate Composites with Modified Minerals

Chemistry & Chemical Technology

New polymer composites on the basis of epoxy resin and different fine dispersed mineral powders (... more New polymer composites on the basis of epoxy resin and different fine dispersed mineral powders (andesite, bentonite, diatomite, liquid glass and quartz sand) were obtained and their mechanical (ultimate strength), thermal (temperature dependence of the softening) and water absorption properties were investigated. It was established that all properties of these materials were essentially improved, when the same fillers modified by tetraetoxysilane (TEOS) were used. It was experimentally shown that composites containing binary fillers-diatomite and andesite at definite ratio-are characterized with so called synergistic effect-the increase in maximal physical or chemical properties. Separately the experimental data on coefficients of reagents diffusion, sorption and penetration, mechanical strengthening, coefficient of heat conductivity and stability to sulfur acid have been investigated. It was shown that exploitation properties of these materials were essentially better in comparison with well known silicate composites. Created materials were characterized by low shrinkage and also low internal stress after hardening. Using the method of mathematical modeling of experiment the optimization of the composition of obtained materials has been performed. Experimental results were explained in terms of structural peculiarities of polymer materials.

Research paper thumbnail of Synthesis And Ionic Conductivity of Siloxane Based Polymer Electrolytes with Propyl Butyrate Pendant Groups

Korean Chemical Engineering Research, 2016

Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl ... more Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, H 2 PtCl 6 and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of CaF 2 , LiF, KF and anhydrous potassium hydroxide in 60-70 o C temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range 3.5×10-4~6 .4×10-7 S/cm.

Research paper thumbnail of Siloxane Matrix wth Methylpropionate Side Groups and Polymer Electrolyte Membranes on Their Base

Analysis and Applications, 2015

Research paper thumbnail of Siloxane Matrix with Methylpropionate Side Groups and Polymer Electrolyte Membranes on Their Basis

Chemical and Structure Modification of Polymers, 2015

Research paper thumbnail of Composites on the Basis of Glycidoxygroup Containing Phenylsilsesquioxanes

Chemical and Structure Modification of Polymers, 2015

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrical conducting polymer composites (ECPC) has b... more The role of the structural peculiarities of electrical conducting polymer composites (ECPC) has been considered. Different conception on the nature of the conductivity, the mechanisms of charge transfer in heterogeneous structures are presented in this review. Experimental results obtained by different scientists are only partially in concordance with existing theoretical models. It is suggested that missing of various physical and chemical factors influencing the processes of electrical current formation in polymer composites is one of the main reasons of the mentioned divergence between theory and experimental results among which the rate of the values of inter-and intra-phase interactions in composites may be considered as a very important factor. The peculiarities of dependence of the conductivity of systems with binary conducting fillers are considered in this work as well.

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrically conductive polymer composites is conside... more The role of the structural peculiarities of electrically conductive polymer composites is considered in this review. Different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented. Experimental results obtained by different scientists are only partially in accord with existing theoretical models. It is suggested that lack of information on various physical

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrically conductive polymer composites is conside... more The role of the structural peculiarities of electrically conductive polymer composites is considered in this review. Different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented. Experimental results obtained by different scientists are only partially in accord with existing theoretical models. It is suggested that lack of information on various physical

Research paper thumbnail of Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

e-Polymers, 2012

Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl a... more Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl acetoacetate and vinyltriethoxysilane at 1:3:1 ratio of initial compounds in the presence of Karstedt’s catalyst (Pt2[(VinSiMe2)2O]3), platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon have been studied and D

Research paper thumbnail of Block-copolymers with Polyphenyl-α-Naphtylsilane Fragments in Dimethylsiloxane Chain

International Journal of Polymeric Materials, 2001

ABSTRACT The Wurtz-type reductive-coupling reaction of dichlorophenyl-α-naphtylsilanes was carrie... more ABSTRACT The Wurtz-type reductive-coupling reaction of dichlorophenyl-α-naphtylsilanes was carried out both in the presence of metalic sodium in toluene solution and in a mixture of toluene and o-xylene (at 1:1 ratio) in the presence of sodium and catalytic amount of mercury. Oligomers of α,ω-dichlorophenyl-α-naphtylsilane with various degrees of polymerization were obtained. By hydrolysis of α,ω-dichlorophenyl-α-naphtylsilane the corresponding α,ω-dihydroxydiorganosilanes has been obtained. The heterofunctional condensation of α,ω-dichloro(dihydroxy)phenyl-α-naphtylsilanes with α,ω-dihydroxy(dichloro)dimethylsiloxanes in the presence of acceptor pyridine has been carried out and polysilane-siloxane block-copolymers were obtained. Depending on the lengths of the rigid and flexible initial oligomers microdomain structure of block-copolymers were observed. The synthesized block-copolymers were characterized by gel permeation chromatography, differential scanning calorimetry and X-ray methods.

Research paper thumbnail of Synthesis and characterization of poly (siloxane‐urethane) s

Polymer International, 1992

A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and po... more A series of polyurethane block copolymers based on hydroxy-terminated polydimethylsiloxane and poly (propylene glycol) soft segments of molecular weights 1818 and 2000, respectively, were synthesized. The hard segments consisted of 4, 4′- ...

Research paper thumbnail of Solid Polymer Electrolyte Membranes on the Basis of Fluorosiloxane Matrix

Chemistry and Chemical Technology, 2021

Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with ... more Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with 2,2,3,3,4,4,5,5-octafluoropentyl acrylate at 1:4.2 ratio of initial compounds catalysed by platinum catalysts have been studied and corresponding adduct D4R' has been obtained. Ring opening polymerization of D4R in the presence of dry potassium hydroxide has been carried out and comb-type polymers with 2,2,3,3,4,4,5,5-octafluoropentyl propionate side groups have been obtained. The synthesized product D4R and polymers were analyzed by FTIR, 1H, 13C, and 29Si NMR spectroscopy. The solid polymer electrolyte membranes have been obtained via sol-gel reactions of polymers with tetraethoxysilane doped with lithium trifluoromethylsulfonate (triflat) and lithium bis(trifluorosulfonyl)imide. It has been found that the electric conductivity of the polymer electrolyte membranes at room temperature changes in the range of (1.9•10-6) – (5.9•10-10) S•cm-1.

Research paper thumbnail of Synthesis and Investigation of Properties of Comb-Type Methylsiloxane Copolymers with Pendant Diphenylsiloxane Groups

Advanced Materials, Polymers, and Composites

Research paper thumbnail of Sawdust based composites

Polymers for Advanced Technologies

Research paper thumbnail of Electric Conductivity of Polymer Composites at Mechanical Relaxation

Chemistry & Chemical Technology

Effect of mechanical relaxations on the relaxation phenomena of electrical conducting polymer com... more Effect of mechanical relaxations on the relaxation phenomena of electrical conducting polymer composites (ECPC) has been investigated. It has been experimentally shown that filler content significantly affects relaxation characteristics of the material. The main reason of these differences is the effect of the filler type on proceeding of relaxation processes. Rubbers with active carbon blacks display the ranges of slow and fast relaxations much more clearly than those with low active carbon black. The effect of the filler type is displayed by formation of an interphase layer and is similar to the effect of the filling degree. In the case of active carbon blacks, the increase of the fillerfiller and polymer-filler interactions is balanced by a high content of low active carbon blacks, since in both cases the modules of the material and internal friction grow.

Research paper thumbnail of Polymer-Silicate Composites with Modified Minerals

Chemistry & Chemical Technology

New polymer composites on the basis of epoxy resin and different fine dispersed mineral powders (... more New polymer composites on the basis of epoxy resin and different fine dispersed mineral powders (andesite, bentonite, diatomite, liquid glass and quartz sand) were obtained and their mechanical (ultimate strength), thermal (temperature dependence of the softening) and water absorption properties were investigated. It was established that all properties of these materials were essentially improved, when the same fillers modified by tetraetoxysilane (TEOS) were used. It was experimentally shown that composites containing binary fillers-diatomite and andesite at definite ratio-are characterized with so called synergistic effect-the increase in maximal physical or chemical properties. Separately the experimental data on coefficients of reagents diffusion, sorption and penetration, mechanical strengthening, coefficient of heat conductivity and stability to sulfur acid have been investigated. It was shown that exploitation properties of these materials were essentially better in comparison with well known silicate composites. Created materials were characterized by low shrinkage and also low internal stress after hardening. Using the method of mathematical modeling of experiment the optimization of the composition of obtained materials has been performed. Experimental results were explained in terms of structural peculiarities of polymer materials.

Research paper thumbnail of Synthesis And Ionic Conductivity of Siloxane Based Polymer Electrolytes with Propyl Butyrate Pendant Groups

Korean Chemical Engineering Research, 2016

Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl ... more Hydrosilylation reactions of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl butyrate catalyzed by Karstedt's, H 2 PtCl 6 and Pt/C catalyst were studied and 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane was obtained. The reaction order, activation energies and rate constants were determined. Ringopening polymerization of 2.4.6.8-tetra (propyl butyrate)-2.4.6.8-tetramethylcyclotetrasiloxane in the presence of CaF 2 , LiF, KF and anhydrous potassium hydroxide in 60-70 o C temperature range was carried out and methylsiloxane oligomers with regular arrangement of propyl butyrate pendant groups were obtained. The synthesized products were studied by FTIR and NMR spectroscopy. The polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography and DSC analyses. Via sol-gel processes of oligomers doped with lithium trifluoromethylsulfonate or lithium bis (trifluoromethylsulfonyl)imide, solid polymer electrolyte membranes were obtained. The dependences of ionic conductivity of obtained polyelectrolytes on temperature and salt concentration were investigated, and it was shown that electric conductivity of the polymer electrolyte membranes at room temperature changed in the range 3.5×10-4~6 .4×10-7 S/cm.

Research paper thumbnail of Siloxane Matrix wth Methylpropionate Side Groups and Polymer Electrolyte Membranes on Their Base

Analysis and Applications, 2015

Research paper thumbnail of Siloxane Matrix with Methylpropionate Side Groups and Polymer Electrolyte Membranes on Their Basis

Chemical and Structure Modification of Polymers, 2015

Research paper thumbnail of Composites on the Basis of Glycidoxygroup Containing Phenylsilsesquioxanes

Chemical and Structure Modification of Polymers, 2015

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrical conducting polymer composites (ECPC) has b... more The role of the structural peculiarities of electrical conducting polymer composites (ECPC) has been considered. Different conception on the nature of the conductivity, the mechanisms of charge transfer in heterogeneous structures are presented in this review. Experimental results obtained by different scientists are only partially in concordance with existing theoretical models. It is suggested that missing of various physical and chemical factors influencing the processes of electrical current formation in polymer composites is one of the main reasons of the mentioned divergence between theory and experimental results among which the rate of the values of inter-and intra-phase interactions in composites may be considered as a very important factor. The peculiarities of dependence of the conductivity of systems with binary conducting fillers are considered in this work as well.

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrically conductive polymer composites is conside... more The role of the structural peculiarities of electrically conductive polymer composites is considered in this review. Different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented. Experimental results obtained by different scientists are only partially in accord with existing theoretical models. It is suggested that lack of information on various physical

Research paper thumbnail of Physical Principles of the Conductivity of Electrically Conductive Polymer Composites (Review)

Molecular Crystals and Liquid Crystals, 2012

The role of the structural peculiarities of electrically conductive polymer composites is conside... more The role of the structural peculiarities of electrically conductive polymer composites is considered in this review. Different conceptions of the nature of the conductivity and the mechanisms of charge transfer in heterogeneous structures are presented. Experimental results obtained by different scientists are only partially in accord with existing theoretical models. It is suggested that lack of information on various physical

Research paper thumbnail of Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

e-Polymers, 2012

Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl a... more Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl acetoacetate and vinyltriethoxysilane at 1:3:1 ratio of initial compounds in the presence of Karstedt’s catalyst (Pt2[(VinSiMe2)2O]3), platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon have been studied and D