The work is devoted to studying the properties of polydimethylsiloxane rubber crosslinked with MQ copolymer and modified with organosilicon compounds of different architectures: asymmetric stereoregular organosilicon stars with flexible siloxane arms and organosilicon nanogel. The statistics of crystallization of water droplets on polydimethylsiloxane-rubber-based coatings has been investigated at temperatures of –15 and –20°С. It has been shown that the coatings are hydrophobic and exhibit anti-icing properties. At –15°С, the droplets on the surfaces of these coatings may remain in a metastable supercooled state for up to 30 hours. At –20°С, the time of droplet crystallization is reduced to 30 min. Under isothermal low-temperature conditions, the positive effect of the modifiers incorporated into polydimethylsiloxane rubber crosslinked with MQ copolymer manifests itself as a decreased rate of droplet crystallization on the coatings containing 1 wt % nanogel or organosilicon stars with flexible siloxane arms as compared with that on the initial polymer.

Polyblock butylenoxide-siloxaneurethane elastomers with a specific chemical structure defined by a changed content of butylene oxide and dimethylsiloxane prepolymers with NCO terminal groups are prepared by a directed one-step synthetic procedure. The synthesis is carried out at room temperature in methyl ethyl ketone without catalysts and chain extenders using aromatic diamines as crosslinking agents. The proposed method allows one to obtain copolymers with a different structure. Such copolymers have high deformation and strength characteristics and are promising in medicine.

Organo-mineral composite materials based on sodium liquid glass combined with tolylene-2,4-diisocyanate (TDI), polyisocyanate, and epoxy oligomer have been synthesized. When heated, the organic components of the composites form a polymer network through the trimerization reaction and TDI curing of the epoxy oligomer. The composite materials after heating to 130°C have a uniform structure. The resulting hybrid composite materials are not brittle and exhibit enhanced heat resistance as compared to common polyisocyanurate compositions. Hybrid composites can find wide application in various fields of engineering.

Nanocomposites based on polyepoxy isocyanurate crosslinked systems of different chemical composition were produced in order to investigate the specific effect of technical nanocarbon on each individual polymer network. Monodispersed carbon particles were produced by methane chlorination conducted in a continuous reactor in a non-equilibrium regime with a chlorine deficit. The dependences of the forced elasticity limit, stress relaxation, etc., on the degree of filling were analysed. The possibility of interphase interaction between a specific polyepoxy isocyanurate network and ‘nanofiller’ was investigated. It was shown that a fairly low concentration (1 wt%) of monodispersed carbon particles of 20–25 nm size leads to a 25–30% increase in the elastic modulus and forced elasticity limit; similarly, the relaxation characteristics are also increased. It was established that improvement in a number of such properties is connected with the greater influence of interphase interactions between the polymer and filler on account of the large surface layer area.

A scheme has been developed for calculating the glass transition temperature and flow temperature of plasticised polymers. The scheme takes into account the chemical structure of the polymer and plasticiser, the molecular weight of the polymer, the intermolecular interaction between the polymer and plasticiser, the van der Waals volume of the repeating unit of the polymer and the plasticiser molecule, and the plasticiser concentration. The thinning effect is also taken into account, as manifested by a reduction in the viscosity of the polymer–plasticiser system with increasing plasticiser concentration.

A theoretical analysis was made of the effect of nanoparticles on the glass transition temperature of polymer nanocomposites. Account was taken of the effect of the chemical structure of the polymer matrix and the concentration, size, and shape of the nanoparticles. Experimental checking was done for nanocomposites based on copolymers of styrene butadiene rubber, polyisoprene, and polybutadiene.

A calculation scheme for prediction of the water permeability through polymers has been developed. A relationship for determining the activation energy of the permeation process has been proposed. The calculation is based on a set of summarized atomic constants with consideration for the chemical structure of the polymer, the degree of crystallinity, temperature, and the free (empty) volume. The method is computerized. The computer program makes it possible to solve not only the problem of estimating the polymer properties on the basis of the chemical structure of the repeating unit but also the inverse problem of searching for polymer structures with the given permeability range.

A calculation method for prediction of water permeability through polymers is suggested. An appropriate equation for calculating the activation free energy of permeability is proposed. The method is based on a set of atomic constants associated with the polymer-water interaction energy. The chemical structure of polymers as well as the degree of crystallininty, temperature, and free volume are taken into account. The method is also applicable for polymeric nanocomposites.

The effect of nanoparticles on glass-transition temperature T g and the elastic modulus of a cycloaliphatic epoxy resin cured with methylhexahydrophthalic anhydride is theoretically analyzed. The analysis was performed with allowance for the following factors: the chemical structure of the polymer, the chemical structures of the nanoparticles and their surfaces if they are modified, the concentrations and shapes of nanoparticles (spherical, plate, cylindrical), the concentration of functional groups on the surfaces of nanoparticles, the energy of intermolecular interaction between a polymer and a nanoparticle, and the possibility of chemical interaction between a polymer and the surfaces of nanoparticles. The most pronounced effect on T g is exerted by cylindical nanotubes, whose surfaces are modified with OH groups, which give rise to hydrogen bonding. The least effect is exerted by spherical nanoparticles. After the introduction of SiO2 nanoparticles, the elastic moduli of nanocomposites increase by a factor of 1.15 at an amount of nanoparticles up to 20%.

Проведен теоретический анализ влияния наночастиц на температуру стеклования Tg и модуль упругости циклоалифатической эпоксидной смолы, отвержденной метилгексагидрофталевым ангидридом. Принимали во внимание следующие факторы: химическое строение полимера, химическое строение наночастиц и их поверхности в случае ее модификации, концентрацию наночастиц, их форму (сферические, пластины, цилиндры), концентрацию функциональных групп на поверхности наночастицы, энергию межмолекулярного взаимодействия между полимером и наночастицей, возможность химического взаимодействия между полимером и поверхностью наночастицы. Наибольшее влияние на изменение Tg оказывают цилиндрические нанотрубки, поверхность которых модифицирована ОН-группами, приводящими к образованию водородных связей; наименьшее – сферические наночастицы. Модуль упругости нанокомпозитов при введении SiO2-наночастиц возрастает в 1.15 раза при их массовом содержании до 20%.

A number of new fluoroalkyl ether-containing polythiophenes are synthesized via oxidative polymerization in supercritical CO 2 (scCO 2 ) and chloroform. In both cases, high-molecular-mass polymers with high yields are prepared. The properties of the polymers synthesized in scCO 2 , such as molecular mass, polydispersity, conjugation, and UV absorption, are similar to the properties of the polymers obtained in chloroform. All poly(fluoroalkyl ether thiophenes) show solubility in DMF, toluene, THF, chloroform, and acetone. The glass-transition temperatures of the polymers are in the range 58–82°C, and the temperatures corresponding to 10% loss in their weight are in the ranges 248–294 and 260–303°C for poly(fluoroalkyl ether thiophenes) synthesized in scCO 2 and chloroform, respectively. All polymers fluoresce in the blue region with emission maxima at 506 to 526 nm. Because of the unique combination of fluoroalkyl and carbonyl groups, poly(fluoroalkyl ether thiophenes) feature good solubility in scCO 2 , which is a promising alternative solvent for the oxidative polymerization of fluoroalkyl ether thiophenes.

Data on the synthesis and study of gradient polymeric materials obtained over the last decade are summarized. The review begins with a short description of works that reported the first data on gradient materials. The following chapters deal with a detailed account of principle for preparing gradient materials of new type that provide extremely wide range of elastic modulus continuously varying in the prescribed direction. Gradient materials derived from poly(urethane-isocyanurate) net-works and their use to prepare films with elastic modulus gradient with depth are considered. A separate chapter is dedicated to composite gradient materials processed by hot molding. The one-step synthesis of poly(urethane-isocyanurate) networks and gradient materials based on poly(urethaneisocyanurate)s combined with polyurethane networks is described. Polyurethane networks and opportunities to control and vary elastic modulus in gradient materials are considered. Gradient polymers and composites constructed from poly(epoxy-isocyanurate) matrices reinforced with carbon cloth or aramid fabric are considered in detail.