Larisa A. Bimendina

Swelling behaviour of a non‐ionic poly(N‐vinyl‐2‐pyrrolidone) gel in a linear poly(acrylic acid) solution

The swelling behaviour of a non-ionic poly(N-vinyl-2-pyrrolidone) hydrogel in a linear poly(acrylic acid) solution upon the influence of chain length, pH, ionic strength, and water/dimethyl sulfoxide composition was studied. The sharp shrinkage of the gel volume within a narrow range of polyacid concentration takes place as a result of the formation of an intermacromolecular gel-polymer complex on the base of hydrogen bonding. According to X-ray diffraction this complex is amorphous. The formation of the gel-polymer complex is a long term process and the system reaches equilibrium within 48 h. The swelling behaviour strongly depends on the chain length of the polyacid whereas it does not depend on the ionic strength. With increasing pH value and changing water/dimethyl sulfoxide composition the gel reswelling is induced. The complex formation with poly(acrylic acid) occurs in the same way for linear and crosslinked poly(N-vinyl-2-pyrrolidone).

Complexes of Water-Soluble Polymers

The complexes of water-soluble polymers with different high- and low-molecular-weight compounds excite great interest at present. They are formed as the result of specific noncovalent interactions ...

Preparation and Characterization of Novel Polymeric Betaines Based on Aminocrotonates

This review summarizes the preparation and physico‐chemical properties of novel polymeric betaines based on ethyl 3‐aminocrotonate and its N‐substituted alkyl derivatives that, in turn, were obtained by condensation of acetoacetic ester with various amines, aminoalcohols, and aminoacids in mild conditions. Stereochemical peculiarities and tautomeric transitions in monomers as well as kinetics and mechanism of formation of linear and crosslinked polybetaines proceeding via Michael addition reaction are outlined. Attention was paid to hydrodynamic, conformational and molecular characteristics of linear and stimuli‐sensitive properties of crosslinked systems as a function of pH, ionic strength, thermodynamic quality of solvents and electric field.

Interaction of richlocain with some linear and crosslinked polymers

Abstract The interaction of local anesthetic drug richlocain with linear polyacrylic acid and crosslinked sodium polyacrylate, linear and crosslinked acrylic acid–Schiff base copolymers has been investigated. The compositions of forming polymer–drug complexes were determined. The influence of external factors such as pH, ionic strength, temperature and thermodynamic quality of solvent on the stability of these complexes was studied. The kinetics and activation energy of drug release from the gel matrix has been evaluated.

Interpolymer complexes of acrylic acid and vinylbutyl ether copolymers with non-ionic and cationic polymers

Copolymers of acrylic acid and vinylbutyl ether AA/VBE) have been involved in complexation reactions with non-ionic poly-N-vinylpyrrolidone (PVP), polyethylene glycol (PEG) and cationic poly-N-methyl-4-vinylethynylpiperidinol-4 (PVEP) and polyvinyl ether of monoethanolamine (PVEMEA) polymers. Interpolymer complexes (IPC) are stabilized due to the formation of either cooperative system of hydrogen or ionic bonds depending on the nature of interacting macromolecular components. The stoichiometry of IPC was determined by electrochemical methods. The stability of IPC depends on thermodynamic quality of the solvents, temperature, and degree of ionization. The permeability of IPC membranes with respect to urea was studied. Copyright

Bovine Serum Albumine Complexation with Some Polyampholytes

Purified protein preparations, which recently were used only in biochemical laboratories, nowadays are coming more and more into our everyday life as medicine preparations and detergents. They are used in fine organic synthesis and food production as well as in a variety of analytical techniques. One of the effective methods of protein separation and purification is protein precipitation (liquid phase splitting) with the help of polyelectrolytes. The most extensively studied protein complexes are mixtures of lysozyme1, albumins2-4, gelatin5,6, and catalase7,8 with weak and strong polyelectrolytes of linear and crosslinked structure.

DESIGN, STRUCTURE, AND BEHAVIOR OF INTERPOLYMER COMPLEX MEMBRANES

Polyelectrolyte complex (PEC) formation reactions between oppositely charged linear polyelectrolytes have been considered in detail.1-4 PEC formation reactions represent an interesting principle to develop PEC films,5 membranes,6 and microcapsules7,8 with unique permselective characteristics towards liquids,9 gases,10 and ions.11 Usually, at a low concentration of mixing polyelectrolytes PECs precipitate and the processing of thin films or membranes becomes a multistage process that includes the following steps: 1) the separation of precipitate; 2) dissolution of precipitate in a ternary mixture consisting of water, organic solvents, and neutral salts; 3) casting; 4) removal of impurities. Whereas a thin interfacial film of PEC about 20 nm thick is rapidly formed at higher polyelectrolyte concentrations (above 0.6 wt.%, or about 0.03 N).11 This film is stoichiometric and because of its impermeability the reaction is stopped after the initial formation of the thin film.