Sarkyt Kudaibergenov - Academia.edu (original) (raw)
Papers by Sarkyt Kudaibergenov
Macromolecular Chemistry and Physics, 1998
ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to nega... more ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to negatively charged model latex systems as well as real mineral dispersions have been considered. It has been shown that the effectiveness of flocculation of disperse particles is maximal at the isoelectric point of polyampholytes. The experimental results obtained on interaction of negatively charged latex particles with synthetic polyampholytes, together with theoretical considerations of Joanny, allowed one to suggest a mechanism of flocculation of colloid dispersions by polyampholytes. It has been established that the interaction of butadiene-styrene latex with polyampholytes is accompanied by the removal of emulsifiers from the surface of latex particles, which in turn leads to a strong hydrophobization of the system and its precipitation.
Macromolecular Chemistry and Physics, 1998
ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to nega... more ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to negatively charged model latex systems as well as real mineral dispersions have been considered. It has been shown that the effectiveness of flocculation of disperse particles is maximal at the isoelectric point of polyampholytes. The experimental results obtained on interaction of negatively charged latex particles with synthetic polyampholytes, together with theoretical considerations of Joanny, allowed one to suggest a mechanism of flocculation of colloid dispersions by polyampholytes. It has been established that the interaction of butadiene-styrene latex with polyampholytes is accompanied by the removal of emulsifiers from the surface of latex particles, which in turn leads to a strong hydrophobization of the system and its precipitation.
Macromolecular Symposia, 2008
Summary: Semi-interpenetrating hydrogels (SIHs) of polyelectrolytes consisting of poly(acrylamide... more Summary: Semi-interpenetrating hydrogels (SIHs) of polyelectrolytes consisting of poly(acrylamide) hydrogel (PAAH) as matrix and sodium poly(styrenesulfonate) (NaPSS), poly(N,N′-dimethyl-N,N′-diallylammonium chloride) (PDMDAAC), stoichiometric interpolyelectrolyte complex of NaPSS-PDMDAAC, and linear polyethyleneimine-metal complexes (PMC) as well as polymer-protected palladium nanoparticles were prepared by in situ polymerization, e.g. crosslinked acrylamide chains were formed in aqueous solutions of NaPSS, PDMDAAC, NaPSS-PDMDAAC (1:1 mol/mol), PMC and palladium nanoparticles protected by poly(N-vinylpyrrolidone) (PVP), poly-(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), and linear poly(ethyleneimine) (LPEI) respectively in the presence of N,N′-methylenebisacrylamide. For each system the equilibrium swelling degree α and the parameters n and k describing the mechanism of water transport into SIHs volume was determined. Catalytic properties of SIHs were studied in allyl alcohol hydrogenation and cyclohexane oxidation reactions.
This review summarizes mostly the literature data accumulated during the last decade on betaine-t... more This review summarizes mostly the literature data accumulated during the last decade on betaine-type polyampholytes. Synthetic pathways to polybetaines consisting of radical polymerization, the Michael addition reaction, and polymer-analogous transformation are discussed together with methods of controlled polymerization, such as group transfer polymerization, atomic transfer radical polymerization, and reversible addition fragmentation transfer. The role of intra- and interchain associates resulting in insolubility in pure water due to the formation of ionically cross-linked network structures, and solubility in saline water because of the disruption of the ionic networks, are outlined. Attention is also paid to the recent advancement of hydrophobically modified polymeric betaines with emphasis on phospholipid-containing vinyl polymers. Polymer complexes of polybetaines, in particular interpolyelectrolyte, polymer–surfactant, and polymer–metal complexes, are considered in the light of the competition between intra- and intermolecular ionic contacts and the cooperative character of interactions. Stimuli-sensitive behavior and morphological changes of polybetaine hydrogels triggered by changes of the pH, ionic strength, water–organic solvent mixture, metal complexation, and DC electric field are discussed with respect to the ionization state of the macromolecules and the thermodynamic quality of solvents, as well as osmotic, chelating, and polarization effects. Some application aspects of polybetaines in medicine, biotechnology, hydrometallurgy, and the oil industry are also discussed.
Journal of Applied Polymer Science, 2005
A new regular polyampholyte, namely poly(N,N-diallyl-N-octadecylamine-alt-(maleic acid)), was stu... more A new regular polyampholyte, namely poly(N,N-diallyl-N-octadecylamine-alt-(maleic acid)), was studied as an additive to crude oil. The amphiphilic polyampholyte proved to be an efficient pour point depressant, to inhibit the deposition of wax, and to improve the viscosity of waxy crude oil from the Akshabulak oilfield (Western Kazakhstan). On optimizing the concentration of the polymer, both the kinematical viscosity and the pour point of waxy crude oils were found to be strongly decreased. The morphology of the paraffin aggregates formed was compared before and after heat treatment of the waxy crude oils, in the presence and the absence of the polymer. The rheological characteristics of the waxy crude oil were markedly improved, in particular, by decreasing the plastic viscosity and the yield stress values upon addition the polymer. The inhibition of wax deposits in the presence of the amphiphilic polyampholyte was interpreted in terms of its interference with the wax crystallization process because of the formation of inverse micellar structures. Although the interaction of the cationic and the anionic groups on the polymer backbone stabilizes the smaller size of the aggregates, the hydrophobic side chains of the polymer provide nucleation sites and cocrystallize with the paraffins, thus modifying the paraffin crystal structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2101–2108, 2005
Macromolecular Rapid Communications, 1994
It is well-known that polyelectrolytes interact with various low-and highmolecular-weight substan... more It is well-known that polyelectrolytes interact with various low-and highmolecular-weight substances and form interpolyelectrolyte complexes (PEC) which usually precipitate from aqueous solution
Macromolecular Rapid Communications, 2002
... Communication. A Novel Class of Betaine-Type Polyampholytes with Stimuli-Responsive and Compl... more ... Communication. A Novel Class of Betaine-Type Polyampholytes with Stimuli-Responsive and Complexing Properties. Raushan B. Koizhaiganova 1 ,; Sarkyt E. Kudaibergenov 1,2 ,; Kurt E. Geckeler 2,3,*. Article first published online: 16 JAN 2003. DOI: 10.1002/marc.200290010 ...
Journal of Applied Polymer Science, 2004
A novel hydrophobic monomer was synthesized from the acetoacetic ester and dodecylamine by conden... more A novel hydrophobic monomer was synthesized from the acetoacetic ester and dodecylamine by condensation reaction in mild conditions. The modification by the dodecyl groups monomer was involved in the Michael addition reaction with acrylic (or methacrylic) acid followed by radical polymerization. Both linear and crosslinked novel betaine-type polyampholytes bearing hydrophobic “tail” and hydrophilic “head” were obtained. The linear polymer was characterized by viscometry, FTIR, and Raman spectroscopy. Swelling–shrinking behavior of linear and crosslinked samples was studied in water–DMF and water–DMSO mixtures. The applicability of hydrophobically modified polybetaines as pour point depressants (fluidity improvers) was also demonstrated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1042–1048, 2004
Langmuir, 1999
ABSTRACT The behavior of amphoteric hydrogels based on vinyl 2-aminoethyl ether and sodium acryla... more ABSTRACT The behavior of amphoteric hydrogels based on vinyl 2-aminoethyl ether and sodium acrylate under the influence of pH, ionic and solvent composition, temperature, and dc electric field has been studied. The excess of positive or negative charges causes the swelling of polyampholyte networks. At the isoelectric point (IEP) the polyampholyte gel is in shrunken state due to the formation of intraionic contacts. An “antipolyelectrolyte” effect is observed at the IEP: the gel considerably swells in the presence of neutral salt. The condensation of bulky anions to positively charged groups of polyampholyte gels enhances the shrinking rate. The shrinking process can be described by apparent first-order kinetics. Polyampholyte gel shrinks with the increasing of temperature when the overall charge is neutral (IEP), while it shrinks effectively with addition of acetone when the overall charge is negative. In dependence of the network net charge, the ionic strength of the external solution, and the direction of dc electric field, the polyampholyte specimen can bend, shrink, swell, and oscillate. Under the same conditions, positively and negatively charged precursors of polyampholytes only swell or shrink. Shrinking and swelling of amphoteric gels are determined by the concentration of mobile ions inside and outside of gel. To interpret the oscillation phenomenon the Donnan equilibrium and water hydrolysis are utilized. The realization of “antipolyelectrolyte” or polyampholyte and polyelectrolyte effects is probably the driving force of gel behavior. The oscillation−relaxation regimes are characterized by numerical value of 1/τ (where τ is the relaxation period). The phase portraits of all oscillation−relaxation curves are in good agreement with the Faraday law.
Macromolecular Chemistry and Physics, 2004
Macromolecular Materials and Engineering, 2005
Journal of Macromolecular Science, Part A, 2007
Preparation of novel poly(alkylamine)-derived hydrogels is described. Polymers are prepared via r... more Preparation of novel poly(alkylamine)-derived hydrogels is described. Polymers are prepared via reaction of various diamines with dihalo compounds or diepoxides. N-substituted polymers are readily prepared by reaction of primary amines with dihalo compounds. The resulting covalently cross-linked polymers exhibit hydrogel behavior (high swell with water) when ionized to polyammonium species at low pH. At high pH, the polymers reside in the free base polyamine form and lose all hydrogel character (they no longer swell in water). Characterization of polymer structure with carbon-13 NMR, thermal analysis, and swell behavior reveals a structure which is highly branched and only loosely cross-linked. In the ionic polyammonium form thermal stability up to ∼300°C is observed. The polymers exhibit activity as bile acid sequestrants significantly superior to cholestyramine, as evidenced by their ability to efficiently bind quantities of cholate when tested in vitro. This behavior indicates that these hydrogels should be very useful for the treatment of hypercholesterolemia.
Polymers for Advanced Technologies, 2000
ABSTRACT The behavior of polyelectrolyte gels under the influence of combined electric and magnet... more ABSTRACT The behavior of polyelectrolyte gels under the influence of combined electric and magnetic fields have been studied. The change of double electric layer potential on the gel–solution interface has been measured. It has been shown that the magnetic field considerably influences the rate of double electric layer formation. The enhancement of electroinduced deformation and collapse is also caused by additional action of the magnetic field. The qualitative interpretation of the observed phenomena is given from the diffusion theory point of view. Copyright © 2000 John Wiley & Sons, Ltd.
Macromolecular Chemistry and Physics, 1997
The formation of polyelectrolyte complexes (PEC) between linear or crosslinked poly[4-(but-3-en-1... more The formation of polyelectrolyte complexes (PEC) between linear or crosslinked poly[4-(but-3-en-1-ynyl)-1-methylpiperidin-4-ol] and linear as well as crosslinked poly(acrylic acid) and poly(methacrylic acid) was studied by potentiometric, conductimetric, turbidimetric, viscometric and volumetric methods in aqueous solution. The composition of PEC particles depends on the conformational state of the interacting macromolecules. The destruction of PEC particles into the individual components takes place at an ionic strength μ > 1 × 10−2 mol/L. The addition of organic solvents causes the conformational transition of PEC particles from the compact structure to an extended one. The sorption of linear polyelectrolytes by networks is accompanied by the shrinking of the polyelectrolyte gels. The kinetics of sorption increases with increasing temperature, ionic strength of the solution and ionization degree. The destruction of PEC consisting of oppositely charged linear and crosslinked polyelectrolytes takes place at high ionic strength of the external solution. The completeness of interpolyelectrolyte reactions with participating of linear and crosslinked poly[4-(but-3-en-1-ynyl)-1-methylpiperidin-4-ol] was detected by the disappearance of the Bohlman band at 2 800 cm−1. The kinetics of sorption of linear polyelectrolytes by crosslinked polyelectrolytes as well as of the competition reaction which is accompanied by the destruction of PEC composed of oppositely charged linear and crosslinked polyelectrolytes was also studied.
Polymer International, 2003
Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine gro... more Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine groups in the main chain and the carboxylic groups in the side chain, have been synthesized by the Michael addition reaction followed by radical copolymerization. The copolymers that exhibited poly(ampholyte–electrolyte) behaviour were used to prepare complexes by reaction with anionic (poly(acrylic acid), poly(styrene sodium sulfonate)), cationic (polyethyleneimine, poly(hexamethylene guanidine)) and non-ionic (poly(N-vinylpyrrolidone), poly(ethylene glycol), poly(vinyl alcohol)) polymers. The influence of external factors, such as solvent quality, temperature, pH and ionic strength, on phase (coil–globule) and volume (swelling–collapse) transitions has been studied.© 2003 Society of Chemical Industry
Macromolecular Chemistry and Physics, 1995
The complex formation reaction of poly(vinyl ethers) of ethylene glycol (1), poly(vinyl ether) of... more The complex formation reaction of poly(vinyl ethers) of ethylene glycol (1), poly(vinyl ether) of diethylene glycol (2), copolymers of vinyl ether of ethylene glycol and vinyl butyl ether (3a–3c) with poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) was studied by conductimetric, viscometric and spectroturbidimetric methods in aqueous solution. It is shown that 1 and 2 do not form polycomplexes with PAA. While an introduction of hydrophobic vinyl butyl ether fragments into the structure of 1 enhances the complexation processes with respect to poly(carboxylic acids), the composition of the polycomplexes is independent of the mixing order of interacting components, temperature and composition of the copolymers. An addition of organic solvents to the aqueous solution of the polycomplexes leads to the cooperative destruction of polycomplex particles. An analysis of IR spectra of the polycomplex films shows the existence of COOH dimers, hydrogen bonds between hydroxyl groups and carboxylic groups as well as ester bonds.
Macromolecular Symposia, 2004
Novel linear and crosslinked polybetaines based on acrylic acid (AA) and ethyl 3-aminocrotonate (... more Novel linear and crosslinked polybetaines based on acrylic acid (AA) and ethyl 3-aminocrotonate (CRO) have been synthesized by a Michael addition reaction followed by radical polymerization. The polymerization of AA and CRO was carried out in bulk, water and organic solvents. The dependence of polymer yield on the molar ratio of monomers and water content was found. Primary attention was paid to linear and crosslinked polybetaines synthesized at equimolar ratio of monomers in the feed. The composition and structure of linear polybetaines was determined by elemental analysis, potentiometric titration, FTIR and NMR spectroscopy. The isoelectric points of linear and crosslinked polybetaines determined by electrophoresis, viscometry and swelling experiments corresponded to pH 2.0-2.2. The stimuli-sensitive properties of amphoteric gels were studied as a function of pH, ionic strength, water-organic solvent mixture, electric, and combined electric and magnetic fields. Appearance of pH gradient within the polyampholyte gel matrix under the externally imposed DC electric field was observed.
Polymer Bulletin, 1984
The interaction of amphoteric macromolecules with ionic surfactants is accompanied by a strong de... more The interaction of amphoteric macromolecules with ionic surfactants is accompanied by a strong decrease of the dimensions of the polyelectrolyte chains, but the complex particles are retained from precipitation by the presence of the hydrophylic components of the polyampholyte. The behaviour of the complex polyampholyte-detergent depends both on the nature of amphoteric copolymers and on the ionic detergents.
Polymer International, 2003
Novel linear and crosslinked polyampholytes of betaine structure based on acrylic acid and ethyl ... more Novel linear and crosslinked polyampholytes of betaine structure based on acrylic acid and ethyl 3-aminocrotonate (ethyl ester of 3-amino-2-butenoic acid) have been synthesized by Michael addition reaction followed by radical copolymerization. The mechanism of formation of monomer and polymer betaines is discussed. The linear polyampholyte has been characterized by potentiometric titration, IR, NMR and GPC. Crosslinked polymeric betaines were synthesized in the presence of N,N′-methylenebisacrylamide. The stimuli-sensitive properties of amphoteric gels have been studied as a function of pH, ionic strength, water–organic mixture composition, electric, and combined electric and magnetic fields. The isoelectric points of linear and crosslinked polymeric betaines correspond to pH 2.0–2.1. The effect of ionic strength on the solution and gel properties of polybetaine has been interpreted on the basis of destruction of inter-chain, intra-chain and intra-group salt bonds. Water–acetone, water–ethanol or water–DMF mixtures cause the shrinking of amphoteric gel due to change of the dielectric constant of the medium and decrease of the osmotic pressure. Electrocollapse is observed under the action of DC electric field. Simultaneously cross action of electric and magnetic fields enhances the collapsing rate. Appearance of pH gradient within the volume of polyampholyte gel under the externally imposed DC electric field has been observed. Copyright © 2003 Society of Chemical Industry
Macromolecular Chemistry and Physics, 1998
ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to nega... more ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to negatively charged model latex systems as well as real mineral dispersions have been considered. It has been shown that the effectiveness of flocculation of disperse particles is maximal at the isoelectric point of polyampholytes. The experimental results obtained on interaction of negatively charged latex particles with synthetic polyampholytes, together with theoretical considerations of Joanny, allowed one to suggest a mechanism of flocculation of colloid dispersions by polyampholytes. It has been established that the interaction of butadiene-styrene latex with polyampholytes is accompanied by the removal of emulsifiers from the surface of latex particles, which in turn leads to a strong hydrophobization of the system and its precipitation.
Macromolecular Chemistry and Physics, 1998
ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to nega... more ABSTRACT The flocculating and stabilizing effect of synthetic polyampholytes with respect to negatively charged model latex systems as well as real mineral dispersions have been considered. It has been shown that the effectiveness of flocculation of disperse particles is maximal at the isoelectric point of polyampholytes. The experimental results obtained on interaction of negatively charged latex particles with synthetic polyampholytes, together with theoretical considerations of Joanny, allowed one to suggest a mechanism of flocculation of colloid dispersions by polyampholytes. It has been established that the interaction of butadiene-styrene latex with polyampholytes is accompanied by the removal of emulsifiers from the surface of latex particles, which in turn leads to a strong hydrophobization of the system and its precipitation.
Macromolecular Symposia, 2008
Summary: Semi-interpenetrating hydrogels (SIHs) of polyelectrolytes consisting of poly(acrylamide... more Summary: Semi-interpenetrating hydrogels (SIHs) of polyelectrolytes consisting of poly(acrylamide) hydrogel (PAAH) as matrix and sodium poly(styrenesulfonate) (NaPSS), poly(N,N′-dimethyl-N,N′-diallylammonium chloride) (PDMDAAC), stoichiometric interpolyelectrolyte complex of NaPSS-PDMDAAC, and linear polyethyleneimine-metal complexes (PMC) as well as polymer-protected palladium nanoparticles were prepared by in situ polymerization, e.g. crosslinked acrylamide chains were formed in aqueous solutions of NaPSS, PDMDAAC, NaPSS-PDMDAAC (1:1 mol/mol), PMC and palladium nanoparticles protected by poly(N-vinylpyrrolidone) (PVP), poly-(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), and linear poly(ethyleneimine) (LPEI) respectively in the presence of N,N′-methylenebisacrylamide. For each system the equilibrium swelling degree α and the parameters n and k describing the mechanism of water transport into SIHs volume was determined. Catalytic properties of SIHs were studied in allyl alcohol hydrogenation and cyclohexane oxidation reactions.
This review summarizes mostly the literature data accumulated during the last decade on betaine-t... more This review summarizes mostly the literature data accumulated during the last decade on betaine-type polyampholytes. Synthetic pathways to polybetaines consisting of radical polymerization, the Michael addition reaction, and polymer-analogous transformation are discussed together with methods of controlled polymerization, such as group transfer polymerization, atomic transfer radical polymerization, and reversible addition fragmentation transfer. The role of intra- and interchain associates resulting in insolubility in pure water due to the formation of ionically cross-linked network structures, and solubility in saline water because of the disruption of the ionic networks, are outlined. Attention is also paid to the recent advancement of hydrophobically modified polymeric betaines with emphasis on phospholipid-containing vinyl polymers. Polymer complexes of polybetaines, in particular interpolyelectrolyte, polymer–surfactant, and polymer–metal complexes, are considered in the light of the competition between intra- and intermolecular ionic contacts and the cooperative character of interactions. Stimuli-sensitive behavior and morphological changes of polybetaine hydrogels triggered by changes of the pH, ionic strength, water–organic solvent mixture, metal complexation, and DC electric field are discussed with respect to the ionization state of the macromolecules and the thermodynamic quality of solvents, as well as osmotic, chelating, and polarization effects. Some application aspects of polybetaines in medicine, biotechnology, hydrometallurgy, and the oil industry are also discussed.
Journal of Applied Polymer Science, 2005
A new regular polyampholyte, namely poly(N,N-diallyl-N-octadecylamine-alt-(maleic acid)), was stu... more A new regular polyampholyte, namely poly(N,N-diallyl-N-octadecylamine-alt-(maleic acid)), was studied as an additive to crude oil. The amphiphilic polyampholyte proved to be an efficient pour point depressant, to inhibit the deposition of wax, and to improve the viscosity of waxy crude oil from the Akshabulak oilfield (Western Kazakhstan). On optimizing the concentration of the polymer, both the kinematical viscosity and the pour point of waxy crude oils were found to be strongly decreased. The morphology of the paraffin aggregates formed was compared before and after heat treatment of the waxy crude oils, in the presence and the absence of the polymer. The rheological characteristics of the waxy crude oil were markedly improved, in particular, by decreasing the plastic viscosity and the yield stress values upon addition the polymer. The inhibition of wax deposits in the presence of the amphiphilic polyampholyte was interpreted in terms of its interference with the wax crystallization process because of the formation of inverse micellar structures. Although the interaction of the cationic and the anionic groups on the polymer backbone stabilizes the smaller size of the aggregates, the hydrophobic side chains of the polymer provide nucleation sites and cocrystallize with the paraffins, thus modifying the paraffin crystal structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2101–2108, 2005
Macromolecular Rapid Communications, 1994
It is well-known that polyelectrolytes interact with various low-and highmolecular-weight substan... more It is well-known that polyelectrolytes interact with various low-and highmolecular-weight substances and form interpolyelectrolyte complexes (PEC) which usually precipitate from aqueous solution
Macromolecular Rapid Communications, 2002
... Communication. A Novel Class of Betaine-Type Polyampholytes with Stimuli-Responsive and Compl... more ... Communication. A Novel Class of Betaine-Type Polyampholytes with Stimuli-Responsive and Complexing Properties. Raushan B. Koizhaiganova 1 ,; Sarkyt E. Kudaibergenov 1,2 ,; Kurt E. Geckeler 2,3,*. Article first published online: 16 JAN 2003. DOI: 10.1002/marc.200290010 ...
Journal of Applied Polymer Science, 2004
A novel hydrophobic monomer was synthesized from the acetoacetic ester and dodecylamine by conden... more A novel hydrophobic monomer was synthesized from the acetoacetic ester and dodecylamine by condensation reaction in mild conditions. The modification by the dodecyl groups monomer was involved in the Michael addition reaction with acrylic (or methacrylic) acid followed by radical polymerization. Both linear and crosslinked novel betaine-type polyampholytes bearing hydrophobic “tail” and hydrophilic “head” were obtained. The linear polymer was characterized by viscometry, FTIR, and Raman spectroscopy. Swelling–shrinking behavior of linear and crosslinked samples was studied in water–DMF and water–DMSO mixtures. The applicability of hydrophobically modified polybetaines as pour point depressants (fluidity improvers) was also demonstrated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1042–1048, 2004
Langmuir, 1999
ABSTRACT The behavior of amphoteric hydrogels based on vinyl 2-aminoethyl ether and sodium acryla... more ABSTRACT The behavior of amphoteric hydrogels based on vinyl 2-aminoethyl ether and sodium acrylate under the influence of pH, ionic and solvent composition, temperature, and dc electric field has been studied. The excess of positive or negative charges causes the swelling of polyampholyte networks. At the isoelectric point (IEP) the polyampholyte gel is in shrunken state due to the formation of intraionic contacts. An “antipolyelectrolyte” effect is observed at the IEP: the gel considerably swells in the presence of neutral salt. The condensation of bulky anions to positively charged groups of polyampholyte gels enhances the shrinking rate. The shrinking process can be described by apparent first-order kinetics. Polyampholyte gel shrinks with the increasing of temperature when the overall charge is neutral (IEP), while it shrinks effectively with addition of acetone when the overall charge is negative. In dependence of the network net charge, the ionic strength of the external solution, and the direction of dc electric field, the polyampholyte specimen can bend, shrink, swell, and oscillate. Under the same conditions, positively and negatively charged precursors of polyampholytes only swell or shrink. Shrinking and swelling of amphoteric gels are determined by the concentration of mobile ions inside and outside of gel. To interpret the oscillation phenomenon the Donnan equilibrium and water hydrolysis are utilized. The realization of “antipolyelectrolyte” or polyampholyte and polyelectrolyte effects is probably the driving force of gel behavior. The oscillation−relaxation regimes are characterized by numerical value of 1/τ (where τ is the relaxation period). The phase portraits of all oscillation−relaxation curves are in good agreement with the Faraday law.
Macromolecular Chemistry and Physics, 2004
Macromolecular Materials and Engineering, 2005
Journal of Macromolecular Science, Part A, 2007
Preparation of novel poly(alkylamine)-derived hydrogels is described. Polymers are prepared via r... more Preparation of novel poly(alkylamine)-derived hydrogels is described. Polymers are prepared via reaction of various diamines with dihalo compounds or diepoxides. N-substituted polymers are readily prepared by reaction of primary amines with dihalo compounds. The resulting covalently cross-linked polymers exhibit hydrogel behavior (high swell with water) when ionized to polyammonium species at low pH. At high pH, the polymers reside in the free base polyamine form and lose all hydrogel character (they no longer swell in water). Characterization of polymer structure with carbon-13 NMR, thermal analysis, and swell behavior reveals a structure which is highly branched and only loosely cross-linked. In the ionic polyammonium form thermal stability up to ∼300°C is observed. The polymers exhibit activity as bile acid sequestrants significantly superior to cholestyramine, as evidenced by their ability to efficiently bind quantities of cholate when tested in vitro. This behavior indicates that these hydrogels should be very useful for the treatment of hypercholesterolemia.
Polymers for Advanced Technologies, 2000
ABSTRACT The behavior of polyelectrolyte gels under the influence of combined electric and magnet... more ABSTRACT The behavior of polyelectrolyte gels under the influence of combined electric and magnetic fields have been studied. The change of double electric layer potential on the gel–solution interface has been measured. It has been shown that the magnetic field considerably influences the rate of double electric layer formation. The enhancement of electroinduced deformation and collapse is also caused by additional action of the magnetic field. The qualitative interpretation of the observed phenomena is given from the diffusion theory point of view. Copyright © 2000 John Wiley & Sons, Ltd.
Macromolecular Chemistry and Physics, 1997
The formation of polyelectrolyte complexes (PEC) between linear or crosslinked poly[4-(but-3-en-1... more The formation of polyelectrolyte complexes (PEC) between linear or crosslinked poly[4-(but-3-en-1-ynyl)-1-methylpiperidin-4-ol] and linear as well as crosslinked poly(acrylic acid) and poly(methacrylic acid) was studied by potentiometric, conductimetric, turbidimetric, viscometric and volumetric methods in aqueous solution. The composition of PEC particles depends on the conformational state of the interacting macromolecules. The destruction of PEC particles into the individual components takes place at an ionic strength μ > 1 × 10−2 mol/L. The addition of organic solvents causes the conformational transition of PEC particles from the compact structure to an extended one. The sorption of linear polyelectrolytes by networks is accompanied by the shrinking of the polyelectrolyte gels. The kinetics of sorption increases with increasing temperature, ionic strength of the solution and ionization degree. The destruction of PEC consisting of oppositely charged linear and crosslinked polyelectrolytes takes place at high ionic strength of the external solution. The completeness of interpolyelectrolyte reactions with participating of linear and crosslinked poly[4-(but-3-en-1-ynyl)-1-methylpiperidin-4-ol] was detected by the disappearance of the Bohlman band at 2 800 cm−1. The kinetics of sorption of linear polyelectrolytes by crosslinked polyelectrolytes as well as of the competition reaction which is accompanied by the destruction of PEC composed of oppositely charged linear and crosslinked polyelectrolytes was also studied.
Polymer International, 2003
Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine gro... more Novel linear and crosslinked copolymers of acrylic acid and Schiff base, containing the amine groups in the main chain and the carboxylic groups in the side chain, have been synthesized by the Michael addition reaction followed by radical copolymerization. The copolymers that exhibited poly(ampholyte–electrolyte) behaviour were used to prepare complexes by reaction with anionic (poly(acrylic acid), poly(styrene sodium sulfonate)), cationic (polyethyleneimine, poly(hexamethylene guanidine)) and non-ionic (poly(N-vinylpyrrolidone), poly(ethylene glycol), poly(vinyl alcohol)) polymers. The influence of external factors, such as solvent quality, temperature, pH and ionic strength, on phase (coil–globule) and volume (swelling–collapse) transitions has been studied.© 2003 Society of Chemical Industry
Macromolecular Chemistry and Physics, 1995
The complex formation reaction of poly(vinyl ethers) of ethylene glycol (1), poly(vinyl ether) of... more The complex formation reaction of poly(vinyl ethers) of ethylene glycol (1), poly(vinyl ether) of diethylene glycol (2), copolymers of vinyl ether of ethylene glycol and vinyl butyl ether (3a–3c) with poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) was studied by conductimetric, viscometric and spectroturbidimetric methods in aqueous solution. It is shown that 1 and 2 do not form polycomplexes with PAA. While an introduction of hydrophobic vinyl butyl ether fragments into the structure of 1 enhances the complexation processes with respect to poly(carboxylic acids), the composition of the polycomplexes is independent of the mixing order of interacting components, temperature and composition of the copolymers. An addition of organic solvents to the aqueous solution of the polycomplexes leads to the cooperative destruction of polycomplex particles. An analysis of IR spectra of the polycomplex films shows the existence of COOH dimers, hydrogen bonds between hydroxyl groups and carboxylic groups as well as ester bonds.
Macromolecular Symposia, 2004
Novel linear and crosslinked polybetaines based on acrylic acid (AA) and ethyl 3-aminocrotonate (... more Novel linear and crosslinked polybetaines based on acrylic acid (AA) and ethyl 3-aminocrotonate (CRO) have been synthesized by a Michael addition reaction followed by radical polymerization. The polymerization of AA and CRO was carried out in bulk, water and organic solvents. The dependence of polymer yield on the molar ratio of monomers and water content was found. Primary attention was paid to linear and crosslinked polybetaines synthesized at equimolar ratio of monomers in the feed. The composition and structure of linear polybetaines was determined by elemental analysis, potentiometric titration, FTIR and NMR spectroscopy. The isoelectric points of linear and crosslinked polybetaines determined by electrophoresis, viscometry and swelling experiments corresponded to pH 2.0-2.2. The stimuli-sensitive properties of amphoteric gels were studied as a function of pH, ionic strength, water-organic solvent mixture, electric, and combined electric and magnetic fields. Appearance of pH gradient within the polyampholyte gel matrix under the externally imposed DC electric field was observed.
Polymer Bulletin, 1984
The interaction of amphoteric macromolecules with ionic surfactants is accompanied by a strong de... more The interaction of amphoteric macromolecules with ionic surfactants is accompanied by a strong decrease of the dimensions of the polyelectrolyte chains, but the complex particles are retained from precipitation by the presence of the hydrophylic components of the polyampholyte. The behaviour of the complex polyampholyte-detergent depends both on the nature of amphoteric copolymers and on the ionic detergents.
Polymer International, 2003
Novel linear and crosslinked polyampholytes of betaine structure based on acrylic acid and ethyl ... more Novel linear and crosslinked polyampholytes of betaine structure based on acrylic acid and ethyl 3-aminocrotonate (ethyl ester of 3-amino-2-butenoic acid) have been synthesized by Michael addition reaction followed by radical copolymerization. The mechanism of formation of monomer and polymer betaines is discussed. The linear polyampholyte has been characterized by potentiometric titration, IR, NMR and GPC. Crosslinked polymeric betaines were synthesized in the presence of N,N′-methylenebisacrylamide. The stimuli-sensitive properties of amphoteric gels have been studied as a function of pH, ionic strength, water–organic mixture composition, electric, and combined electric and magnetic fields. The isoelectric points of linear and crosslinked polymeric betaines correspond to pH 2.0–2.1. The effect of ionic strength on the solution and gel properties of polybetaine has been interpreted on the basis of destruction of inter-chain, intra-chain and intra-group salt bonds. Water–acetone, water–ethanol or water–DMF mixtures cause the shrinking of amphoteric gel due to change of the dielectric constant of the medium and decrease of the osmotic pressure. Electrocollapse is observed under the action of DC electric field. Simultaneously cross action of electric and magnetic fields enhances the collapsing rate. Appearance of pH gradient within the volume of polyampholyte gel under the externally imposed DC electric field has been observed. Copyright © 2003 Society of Chemical Industry