The radical polymerization of 2-(perfluorohexyl)ethyl methacrylate (FHEMA) initiated by azobis(isobutyronitrile) in the presence of a commercially available chain transfer agent, 2-cyano-2-propyl dithiobenzoate, carried out in trifluorotoluene (TFT) or in supercritical carbon dioxide (scCO2) was studied for the first time. The conditions were found under which the FHEMA polymerization in TFT or in scCO2 proceeds under homogeneous conditions with reversible chain transfer via the addition–fragmentation mechanism.

Thermoresponsive diblock copolymers (DCs) were prepared by two-stage reversible addition-fragmentation chain transfer/macromolecular design by interchange of xanthate (RAFT/MADIX) polymerization of N -vinylcaprolactam and N -vinylimidazole (VI). The poly( N -vinylcaprolactam) (PVCL) blocks were first synthesized and used as macro-chain transfer agent in VI polymerization. The temperature behavior of PVCL and DCs in aqueous media has been studied by static and dynamic light scattering. It has been shown that the phase separation temperature of both PVCLs and DCs depends on the length of the PVCL chain and the composition of aqueous solvent. The temperature range above the PVCL θ temperature and below the cloud point is characterized by the conformational rearrangements leading to the formation of mesoglobules. The study of catalytic activity of DCs in the hydrolysis reaction of p -nitrophenyl propionate has shown that their activity substantially increases in this transitional temperature region owing to the formation of highly developed hydrophilic–hydrophobic interfaces inside the mesoglobules.

A new method for activating the synthesis of high molecular weight polymer PIM-1 obtained in dimethyl sulfoxide is proposed and studied. A simple and technologically effective process of precipitation polyheterocyclization occurs at 60–80°C for 2–5 h under constant exposure to ultrasound at a frequency of 37 kHz. This method allows one to synthesize the PIM-1 polymer with a molecular weight of up to 121 × 103 and a relatively low polydispersity index of 3.8. In addition to powder materials, microporous nanofibrous materials are obtained by electrospinning from polymer solutions. According to the Brunauer–Emmett–Teller method, the specific surface area of PIM-1 reaches 862 m2/g for powders and 362 m2/g for nanofibers.

The radical polymerization of 2,3,4,5,6-pentafluorostyrene (PFS) in the presence of poly-2-hydroxyethyl methacrylate with a dithiobenzoate end group as a chain transfer agent was studied in DMF-d7 in situ by 1H NMR spectroscopy. It was found that the reaction has virtually no induction period and proceeds at a higher rate than PFS polymerization in the presence of a low-molecular-weight chain transfer agent. A possible reason for the observed kinetic features is the self-assembly of PFS and 2-hydroxyethyl methacrylate diblock copolymers during the polymerization.

A ladder polymer with the intrinsic microporosity PIM-1 has been synthesized via precipitation polycondensation in dimethylsulfoxide and via polycondensation in N,N,N ',N '-tetramethylurea. The molecular weight characteristics of PIM-1 samples have been determined using gel permeation chromatography method. It has been shown that the synthesized polymers are characterized by a high molecular weight (~90 × 103) and by a bimodal molecular weight distribution; in this case, molecular weights of the high-molecular-weight fraction of polymer with the polydispersion coefficient of 2.1–2.4 are practically independent of the nature of the reaction medium. The weight content of the oligomer fraction in the obtained samples has been estimated from gel permeation chromatograms. Gas permeability coefficients of He, H2, O2, N2, CO2, and CH4 for the initial films of the synthesized polymers and the films treated with ethanol have been measured by the chromatographic method at 22 ± 2°С. It has been shown that, for all samples under investigation, the gas permeability coefficients are higher than for the PIM-1 samples described previously in the literature. In this case, the gas permeability and its increase during treatment with ethanol depend on the content of the low-molecular-weight fraction in the sample.

The hemostatic and immunostimulating activity and cytotoxicity were determined for a number of chitosans differing in molecular weight (from 3 to 510 kDa) and degree of acetylation (from 1 to 25 mol%) that were used as adjuvants in inactivated poliomyelitic, influenza, and live influenza vaccines. It has been shown that the hemostatic activity of chitosan increased sharply with an increase in its molecular weight. In oligochitosan with a molecular weight of <16 kDa, it was smaller by a factor of 15–100 than in chitosan with a molecular weight of 20–510 kDa. The level of increase in the immunogenicity of vaccines containing oligochitosan as adjuvants was not lower than that for the vaccine including high-molecular chitosan. However, the immunostimulatory activity of oligochitosan depended on the degree of acetylation, reaching a maximum value at 6 mol%. It was shown that all oligochitosans and chitosans with a molecular mass below ~50 kDa showed almost no cytotoxicity at a concentration of ≤2.5 mg/mL, which enable their use as adjuvants for inactivated and live vaccines at the optimal ratio of molecular weight to the degree of acetylation.

A new monomer, 2,3-bis[6-fluoro-9-(2-octyldodecyl)-9H-carbazol-3-yl]-3,3'-[5,7-di(5-bromothienyl-2)thieno[3,4-b]pyrazine, M1, based on thienopyrazine containing fluorocarbazole substituents in the pyrazine ring has been synthesized. The structure of the compound has been proved by 1H and 13C NMR and elemental analysis. The HOMO and LUMO energies for monomer M1 and its precursor 3 determined by the electrochemical method are–5.03 and–3.31 eV, as well as–5.28 and–3.36 eV, respectively. Band gap widths E g ec are 1.72 and 1.92 eV for compounds M1 and 3, respectively. The new structural fragment has rather deep energy levels of frontier molecular orbitals and a small band gap width; therefore, it is a promising building block for the synthesis of polymers for organic electronics.

A new monomer, the dibromo derivative of fluoranthene 1-[7,10-bis(4-bromophenyl)fluoranthen-8-yl]pyrene, is synthesized and used to prepare three new copolyfluorenes containing 3, 5, and 10 mol % 7,8,10-triarylfluoranthene groups via the Yamamoto reaction. The number-average molecular masses and polydispersities of the polymers vary in ranges 41900–78900 and 2.7–3.5, respectively. All polymers are soluble in common organic solvents, and their glass-transition temperatures are from 95 to 115°C. Temperatures corresponding to a 10% loss in weight during heating in argon and air are in the ranges 420–435 and 405–415°C, respectively. The photoluminescence spectra of the polymers exhibit strong blue emission with a maximum at 418 nm, whereas the absorption spectra show characteristic peaks at 351–357 nm. All polymers possess reversible or partially reversible redox behavior owing to high electric activity and demonstrate redox pairs at 1.51 eV (oxidation) and −2.09 eV (reduction).