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Phase equilibria in systems polystyrene–block and gradient n-butyl acrylate–styrene copolymers are studied for the first time using optical interferometry for polystyrene of various molecular weight and copolymers of different architecture. Phase diagrams, which are characterized by the upper critical solution temperatures, are constructed. The pair interaction parameters for these systems are calculated, and the thermodynamics of mixing of the components is evaluated. The data on the interdiffusion of polystyrene into the copolymer and the copolymer into polystyrene are obtained. The effect of the composition of copolymers on their interaction with polystyrene is analyzed. The friction coefficients of macromolecules and the diffusion coefficients of monomer units are calculated. It is shown that these values are independent of the molecular weight of the diffusant and the architecture of the copolymer.

The structure of n-butyl acrylate–styrene block and gradient copolymers of various compositions is studied in detail, and their glass transition temperatures are determined. Influence of the architecture of copolymer macromolecules on the glass transition temperature is considered. Histograms of the size distribution of phases are constructed, and the density distribution of domains over the cross section of the dispersed phase is estimated. Schematic representations of the structure of the block and gradient copolymers are proposed, and their features are analyzed.

Interdiffusion and phase equilibrium in the system composed of polystyrene and statistical copolymers of butyl acrylate and styrene were studied by optical interferometry. The diagrams of the phase state were for the first time plotted and analyzed; pair interaction parameters were determined. The obtained diagrams are characterized by an upper critical solution temperature (UCST). The dependence of the interaction parameter on copolymer composition, polystyrene molecular weight, and temperature was shown. The data of interdiffusion of polystyrene into copolymers (and vice versa) are presented; they vary within 10–7–10–11 cm2/s. The activation energy of diffusion was calculated. No influence of structural heterogeneity of macromolecules of statistical copolymers on phase characteristics, translational diffusion coefficients, and coordinate of the diffusion front was registered.

The behavior of organosilicon surfactants of different structure in model systems—Langmuir films—at the water/air interface is studied. It is shown that, under the compression of Langmuir films, the conformational states of surfactants of different structure are different. The obtained data make it possible to explain a high stability of polymer suspensions synthesized in the presence of organosilicon surfactants.

Ultrathin fibers of a biodegradable polymer poly(3-hydroxybutyrate) with an encapsulated drug (dipyridamole, 0–5% of poly(3-hydroxybutyrate) mass) are obtained by electrospinning. Introduction of the drug substantially affects the geometric shape and crystallinity of individual filaments as well as the total porosity of the fibrillar film on their basis. As follows from the SEM data, in the absence of the drug or at its low concentration (

The method of optical interferometry is used to study the interaction of PE with PS in situ. On the basis of the obtained data, phase diagrams of the PE–PS system are constructed for a number of molecular masses of the components. For PE and PS oligomers, the UCMT values are determined. Pair parameters for the interaction of homopolymers are calculated, and their dependences on temperature and molecular mass are considered. The quantitative analysis of the behavior of high-molecular-mass fractions of PE and PS at high temperatures is carried out, and the regions of a partial compatibility of the components are predicted.