V.Yu. Baranovsky

Template polymerization of methacrylic acid in the presence of poly(ethylene glycol) and poly(N-vinylpyrrolidone) in benzene

Abstract Heterogeneous radical polymerization of methacrylic acid (MAA) in benzene in the presence of poly(ethylene glycol) (PEG) and poly(N-vinylpyrrolidone) (PVP) was studied. The products of the polymerization are the interpolymer complexes of poly(methacrylic acid) (PMAA) with PEG and PVP. In spite of the daughter polymer PMAA being insoluble in the reaction medium, the polymerization proceeds via a template mechanism which is generally similar to the template polymerization of MAA in the presence of the same templates under homogeneous conditions. In a heterogeneous polymerization, competition between the two templates is possible: the PMAA macroradical with high selectivity chooses the much stronger template PVP.

Thermochemical reactions in polycomplexes

Abstract Polycomplex formation between poly(methacrylic acid) and polyacrylamide in aqueous solutions has been studied by means of viscometry, potentionetry and elemental analysis. Stoichiometry of the polycomplex was found to be 1:1 with respect to unit-moles. I.R.-spectroscopic data give evidence of the co-existence of ladder-like regions and loops in the polycomplexes formed by poly(methacrylic acid) with polyacrylamide and poly(ethylene glycol). The reactivities of the same functional groups in ladder-like regions and loops are different. This difference has been shown taking as an example thermochemical reactions in the above polycomplexes. Dehydrocyclization in the poly(methacrylic acid) chain was found to occur in the loops of both polycomplexes. This intramolecular reaction in the polycomplex of poly(methacrylic acid) with polyacrylamide is followed by intermolecular formation of imide bonds in ladder-like regions.

Complex formation between polymethacrylic acid and copolymers of adipic acid with poly(ethylene glycol) in aqueous solution

Abstract The complex formation between polymethacrylic acid (PMAA) and the copolymers of adipic acid (AdA) with poly(ethylene glycol) (PEG) in dilute solution has been studied. The hydrophobic AdA fragments break the continuous cooperative hydrogen bonds between the polymer components in the polycomplex being however the factor that stabilizes the polycomplex (PMAA.AdA/PEG). If the AdA/PEG copolymers are of one and the same chain length the copolymer having more AdA hydrophobic fragments exhibits greater complex forming ability.

Complexation of poly(methacrylic acid) with poly(ethylene glycol) nonionic surfactants in aqueous solutions

Abstract The interaction between poly(methacrylic acid) (PMAA) and surfactants based on poly(ethylene glycol) in aqueous solutions has been studied by viscometry and potentiometric titration. The interaction proceeds in two stages with increasing concentration of the surfactants. At first, the polycomplex (PMAA surfactant) is formed. The structural state of the surfactant in the polycomplex depends on the hydrophilic-hydrophobic balance of the surfactant. In the second stage at higher concentration of the surfactant, the polycomplex binds the micelles, forming an associate with two possible structures.

Polycondensation of silicic acid in the presence of poly(N-ethyl-4-vinylpyridinium bromide) and properties of the reaction products

Abstract A comparative study was carried out for polyelectrolyte complexes between poly(N-ethyl-4-vinylpyridinium bromide) and poly(silicic acid) sol prepared by mixing of aqueous solutions of the components and by template polycondensation of silicic acid in the presence of the polycation. The polycation template reduces the degree of conversion of the silicic acid. The different properties of the polyelectrolyte complexes formed in the two alternative procedures result from interaction of the polycation with the products of incomplete polycondensation of silicic acid.

Complexation between poly(methacrylic) and poly(acrylic) acids and star‐shaped poly(ethylene glycol) based on pyrogallol

Complex formation between polymethacrylic (PMAA) and polyacrylic acids, and star-shaped poly(ethylene glycol) prepared by ethoxylation of pyrogallol (Pyr-PEG) has been studied viscometrically and by potentiometric titration in water solution. The competitive ability of Pyr-PEG and of the derivatives of the ethoxylation of phenol and hydroquinone in complex formation with PMAA has been compared by UV spectroscopy. Pyr-PEG turns out to be the weakest competitor because of its chemical structure.

Competitive complex forming reactions between monosubstituted and nonsubstituted poly(ethylene glycol)s with poly(methacrylic) acid

A competitive complex forming reaction between a number of monosubstituted poly(ethylene glycol)s (PEG*) containing a hydrophobic group of differing chemical nature and nonsubstituted PEG of various molecular weights with poly(methacrylic acid) (PMAA) was studied. A UV spectroscopy method was used. During the transfer of the hydrophobic chromophoric group from the aqueous medium into the hydrophobic domains of the polycomplex (PMAA.PEG*), a bathochromic effect was observed. The introduction of a hydrophobic group into the PEG chain leads to stabilization of the polycomplex (PMAA.PEG) that is formally the same as growing the chain length of PEG. The polymerization degree of PEG having the same competitive power as PEG* can be used as the peculiar scale of the complex forming ability of PEG* in the complexation with PMAA.

Nonspecific interactions in polymer-polymer reactions—5. Reactions of macromolecular substitution in complexation between poly(methacrylic acid) and mono-substituted poly(ethylene glycol)s

Abstract A competitive complex forming reaction between poly(methacrylic acid) (PMAA) and a number of monosubstituted poly(ethylene glycol)s (PEG∗), containing a hydrophobic group of differing chemical nature has been studied by u.v. spectroscopy. The method is based on the fact that during the transfer of the hydrophobic chromophoric group from the aqueous medium into the hydrophobic domains of the polycomplex ( PMAA · PEG ∗ ) a bathochromic effect is observed.