The article is devoted to the design, development and application of a new generation of binders for various dispersed systems, including soil, ground, sand, waste rock and others. The binders are formed by interaction of oppositely charged polyelectrolytes, both chemically stable and (bio)degradable. The fundamental aspects of interpolyelectrolyte reactions are discussed; the IPC structure and properties of the resulting interpolyelectrolyte complexes (IPCs) allow considering them as unique and universal binders. Numerous results of laboratory experiments and field trials of the IPC formulations are presented. In particular, large-scale tests have been done in the Chernobyl accident zone where the IPC binders were shown to be effective means to suppress water and wind erosion thereby preventing a spread of radioactive particles (radionuclides) from contaminated sites. Ecologically friendly IPC compositions are described, including those based on commercially available polymers; prospects for improving their efficiency and extending the range of their possible use are discussed.

Abstract-Substitution reactions between weakly crosslinked anionic hydrogels (network sodium polyacrylate or network sodium poly(2 acrylamido-2-methyl-1-propanesulfonate)) and nonstoichiometric inter-polyelectrolyte complexes formed by a blocking linear sodium polyacrylate and lyophilizing poly(N,N’-diallyl-N,N’-dimethylammonium chloride) in aqueous media have been revealed and studied. It has been found that both sulfonate and carboxylate networks take up a linear polycation via the formation of a stoichiometric interpolyelectrolyte complex, a phenomenon that results in the collapse of the network. In this case, the blocking polyacrylate anions are quantitatively expelled from the particles of the nonstoichiometric watersoluble complex into the environment and occupy lyophilizing polycations uniformly, a circumstance that results in their precipitation and, consequently, the termination of the substitution reaction. This outcome suggests the presence of feedback in the studied processes. The result for carboxylate networks is completely new and nontrivial; it is indicative of the important role of macromolecular architecture in selecting the direction of a process.

Обнаружены и изучены реакции замещения между слабо сшитыми анионными гидрогелями (сетчатого полиакрилата натрия или сетчатого поли-2-акриламидо-2-метил-1-пропансульфоната натрия) и нестехиометричными интерполиэлектролитными комплексами, образованными блокирующим линейным полиакрилатом натрия и лиофилизирующим поли-N,N-диаллил-N,N-диметиламмоний хлоридом, протекающие в водных средах. Установлено, что как сульфонатная, так и карбоксилатная сетка поглощают линейный поликатион, образуя с ним стехиометричный интерполиэлектролитный комплекс, что приводит к коллапсу сетки. При этом блокирующие полиакрилат-анионы количественно вытесняются из частиц нестехиометричного водорастворимого комплекса в окружающую среду и равномерно заселяют лиофилизирующие поликатионы, что вызывает их осаждение и, как следствие, прекращение реакции замещения. Это свидетельствует о наличии обратной связи в исследуемых процессах. Результат, достигнутый для карбоксилатных сеток, представляется совершенно новым и нетривиальным, он свидетельствует о важной роли архитектуры макромолекул в выборе направления процесса.

The interaction of amphiphilic block copolymers comprising an anionic block (polyacrylate or polymethacrylate) and a hydrophobic block (polystyrene, poly(butyl acrylate) or polyisobutylene) with lightly crosslinked poly( N,N -diallyl- N,N -dimethylammonium chloride) is studied for the first time. It is shown that the cationic hydrogel can sorb anionic amphiphilic block copolymers via electrostatic interaction with the corona of block copolymer micelles. The rate of sorption of block copolymer polyelectrolytes is significantly lower than the rate of sorption of linear polyions and is controlled by the lengths of the hydrophilic and hydrophobic blocks and the flexibility of the latter blocks. The sorption of amphiphilic block copolymers is accompanied by their self-assembly in the polycomplex gel and formation of a continuous hydrophobic layer impermeable to water and the low-molecular-mass salt dissolved in it.

The structure of complexes formed by poly(propylenimine) dendrimers of five generations and anionic micelle-forming surfactants is studied by X-ray diffraction. It is shown that, in complexes of lower generation dendrimers, the lamellar packing of surfactants is dominant. In complexes formed by dendrimers of the fourth and fifth generations, packing typical of compact dendrimer molecules prevails. This packing can be attributed to the distorted dense packing of ball-like complex species. Structural models of complexes that allow for penetration of surfactants into the dendrimer molecule and the size ratio of the aliphatic radical of a surfactant and a dendrimer are advanced.

Various types of structural organization of polycomplex gels based on a lightly crosslinked anionic sulfonate gel and Astramol poly(propyleneimine) dendrimer of the fourth generation were studied. It was shown that along with macroscopic two-phase structure of the core-shell type, which is formed in the process of activated dendrimer sorption by anionic gel, a microheterogeneous composite with polycomplex phase particles of micron dimensions uniformly distributed in the network matrix is also formed. Such microheterogeneous composites are formed as a result of dendrimer molecule redistribution in a lightly crosslinked anionic gel during dendrimer charge change. The parameters of the microheterogeneous structure of polycomplex gel forms were evaluated by the laser scattering technique. It was found that the size of dendrimer aggregates depends on the value of the network degree of swelling.

Изучены реакции комплексных гелей, образованных в результате сорбции слабо сшитыми полиэлектролитными гидрогелями противоположно заряженного полипропилениминового амфолитного дендримера четвертой генерации, с ионогенными мицеллообразующими ПАВ. Установлено, что сорбция комплексными гелями ионов ПАВ, одноименно заряженных с амфолитным дендримером в составе комплекса, обусловлена двумя параллельными химическими реакциями, контролируемыми концентрацией ПАВ и pH среды, которые приводят к формированию тройных комплексов сетка–дендример–ПАВ. Показано, что реакции комплексных гелей с ионами ПАВ, одноименно заряженными с сетчатым полиэлектролитом, позволяют получать в зависимости от pH среды как отрицательно, так и положительно заряженные гидрогели, армированные дисперсными частицами комплекса дендример–ПАВ.

The reactions of complex gels formed via the sorption of a poly(propylenimine) ampholyte dendrimer of the fourth generation by oppositely charged lightly cross-linked polyelectrolyte hydrogels with ionogenic micelle-forming surfactants have been studied. The sorption of surfactant ions likely charged relative to the complexed ampholyte dendrimer by complex gels is associated with two parallel chemical reactions controlled by the concentration of the surfactant and pH which give rise to the formation of network-dendrimer-surfactant tertiary complexes. The reactions of complex gels with surfactant ions likely charged relative to the network polyelectrolyte make it possible at different solution pHs to prepare both negatively and positively charged hydrogels reinforced by disperse particles of the dendrimer-surfactant complex.