The influence of the phase state of the reaction system and the HCl concentration during hydrolytic polycondensation of methyltrichlorosilane on the composition of the formed oligomers, their stability during storage and ability to thermal curing is shown. The technological production process is developed and the scheme of a pilot plant for obtaining oligomethylsilsesquioxanes used for the production of highly filled thermo- and fire-resistant polymer composite materials is presented.

An approach to the description and prediction of the elastic modulus of polymers in a rubbery state is presented. The description is based on the generalized equation proposed earlier by one of the authors of the work. The equation takes into account the contribution of cross-linked points to the elasticity of elastomers. This made it possible to describe the dependences of the elastic modulus on the concentration and size of crystallites. Such dependencies were obtained for the following polymers: polypropylene, polyisoprene, polybutadiene, polytetrafluoroethylene, polychloroprene, polydimethylsiloxane. For the same crystallite sizes, the elastic moduli for different polymers are close to each other, but they increase significantly with a decrease in the volume of crystallites.

In this work mechanism of polymer particles formation during styrene heterophase polymerization in the presence of waterinsoluble organosilicon surfactant was investigated. Dependency between monomer conversion rate from early stages of polymerization and particle diameters change, molecular weight, particle size and molecular weight distribution was analyzed. The effect of the gel effect and Ostwald maturation on particle diameter and polymer molecular weight was evaluated.

The paper presents a method for determining the maximum content of dispersed filler (φ_m) in dispersed-filled polymer composite materials (DFPCM) by oligomer-absorption.

For the first time, data on the values of the parameter φ_m in the DNPCM obtained from oligomer- (Y, g/100 g) and oil absorption method (X, g/100 g) are presented.

The dependences of the parameter φ_m on the particles size for fillers with a particle size from 50nm to 250 microns are presented.

It is shown, that the main advantage of using the new method for determining the parameter φ_m is the possibility to bring the dispersed system closer to the real conditions for DFPCM production and thus, to increase the reliability of the results.

The article presents the results of a study of the chemical structure, low molecular weight impurities and heat stability according to TGA/DTA of domestic polyphenylene sulfides (PPS) with different molecular weight and their imported analogues. It is shown that domestic samples are almost identical to imported analogues and can be used as a binder for highly filled reinforced polymer composite materials for structural purposes.

The reaction of epoxyphosphazenes with methacrylic acid was used to synthesize methacrylate-containing phosphazene oligomers (MPO) used to modify dental restorative materials.

The introduction of 1015 wt.% MPO into the base bis-methacrylate binder composition can significantly increase the adhesion of modified cured compositions to tooth tissues and metals, as well as improve water resistance while maintaining the required strength indicators and other physicochemical characteristics required by GOST.

The paper presents the results of a study of the kinetics and level of residual stresses during the curing of systems based on ED-20 epoxy oligomer with amine curing agent (TETA) and active diluents (AD) having different nature, structure and characteristics (laproxides and laprolate).

The effect of the structure, AD content, and curing temperature on the kinetics and level of residual stresses in the ED-20 + TETA + AD systems is shown.

It has been established that the most effective AD for reducing residual stresses in the ED-20 + TETA systems are laproxides of grades E-181, 703 and laprolat 301 at a content of 0.15-0.20 vol.

Optimal compositions of binders based on epoxy oligomers with active diluents with low level of residual stresses (no more than ~2 MPa), shrinkage of ~3%, initial viscosity of ~0.2 Pa·s at curing temperature of up to 60°C are proposed, which guarantees high-quality impregnation of fibrous fillers and high level having physical and mechanical characteristics of reinforced plastics.

The efficiency of thermal stabilization of polyvinyl chloride films containing a calcium-zinc stabilizer with the addition of pentaerythritol, magnesium pentaerythritate and zinc pentaerythritate has been investigated. A high synergistic effect of the use of magnesium pentaerythritol was revealed during the thermal stabilization of the polyvinyl chloride – calcium-zinc stabilizer system with a 1:1 stearate ratio. The influence of composition’s changes on the thermal stability of the films is considered and an explanation of the observed changes is proposed. The mechanisms of thermal stabilization of PVC by magnesium pentaerythritol and zinc pentaerythritol are proved.

The technology for obtaining highly filled composite materials based on ethylene vinyl acetate (EVA) and styrene block copolymer (SBS) is presented. Crumb rubber from recycling tires was used as a filler. The working temperature of rubber crumb activation has been determined, namely, the vulcanization temperature of the non-crosslinked part is 170°C. The amount of noncrosslinked part in the rubber crumb was established to be not less than 2%.

In this work, methods for obtaining unsaturated polyester resins based on the products of chemical recycling of post-consumer polyethylene terephthalate with various agents are compared. A process based on simultaneous glycolysis and interchain exchange of polyethylene terephthalate and oligoethylene phthalate with hydroxyl end groups has been proposed. The advantages of this process are shown, including rapid obtaining polyester resins of high molecular weight and the lesser influence of side reactions and degradation reactions. The unsaturated resin with a weight average molecular weight of 3100 g/mol was obtained.

The aryloxyphosphazenes containing carboxylic groups in phosphorus-linked radicals and capable of copolymerization with acrylic binders were used as modifiers of dental polymer compositions. Filled modified dental compositions have been obtained and tested. It has been shown that the best mechanical and physicochemical parameters are exhibited by cured compositions with a modifier based on aryloxyphosphazene with 4-hydroxycinnamic and eugenol radicals in the phosphazene ring.