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It was found that to increase the adhesive and physicomechanical properties of compositions based on epoxy resin and polysulfide rubber (thiokol), cured without heat treatment, it is necessary to carry out a preliminary thioetherification reaction (PRTE) due to the interaction of rubber mercaptan groups and oxirane cycles of epoxy resin at elevated temperatures and then use the product of this reaction to cure at room temperature. Composite materials based on the products of the thioetherification reaction significantly surpass analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work, and specific impact strength. It is shown that the introduction of both diluents and plasticizers into the products of the preliminary thioetherification reaction of epoxy resins and polysulfide rubbers leads to an increase in the parameters of tensile strength and deformation capacity. The greatest strengthening effect is achieved with the use of oligoesteracrylate MGF-9 and glycidyl ether of diethylene glycol DEG-1, the smallest - with the introduction of the plasticizer EDOS. It was found that the introduction of plasticizers promotes some increase in the adhesive strength, but much less in comparison with the cohesive strength. In this case, the adhesion and cohesive characteristics change antibatically. It has been shown by dynamic mechanical spectrometry that the presence of diluents and plasticizers in epoxy-polysulfide composites leads to a decrease in the temperatures of the maximum values of the tangent of the angle of mechanical losses, loss modulus, the initial and final sections of the transition of the material from the glassy to the highly elastic state, as well as the density of the chemical network in the epoxy matrix.

A tin-bromine-containing resin was prepared by the interaction of industrial ED-16 epoxy resin with dibutyltin dibromide. A comparative study of the physical, mechanical and relaxation properties of composites based on the original and modified resins cured at different temperatures has been carried out. It has been shown that the composite materials based on a modified resin are characterized by lower values of tensile strength, elastic modulus, fracture work and glass transition temperature as compared with the samples based on the original epoxy resin. The effect of water on the deformation and strength properties of composites was studied. A complex mechanism of the influence of moisture sorbed by the polymer on the complex of properties has been established, which may result from the imposition of the effects of plasticization and additional curing of the epoxy matrix. At short exposure times, the effect of the sorbed liquid is mainly aimed at weakening the intermolecular interaction in the sample, as a result of which its tensile strength decreases and its deformation capacity increases. At long exposure times, post-curing processes prevail, leading to an increase in the crosslinking density and, as a consequence, to a decrease in deformation capacity and an increase in the strength index. It has been shown that epoxy composites containing resin modified with dibutyltin dibromide are characterized by increased fungitoxicity and fire resistance. The studied polymers can be considered as promising for the production of antifouling coatings for hydraulic equipment on their basis.

The article presents the results of the study aimed at establishing the main process parameters of the preparation of an electrically conductive composite material containing silicon carbide, graphite, aluminous cement and sodium silicate. This composite material can be used as a heating element in heat accumulators for the operating temperature range of 600–10000C. The effects of the amount of sodium silicate within the range of 12–18 wt.% and the compacting pressure within the range of 40-70 N / mm2 on the changes in the properties of the samples after drying were investigated. It was established that the mechanical strength of the samples of 34.2 N mm–2 and 33.4 N mm–2 can be achieved at the compacting pressure of 60 N mm–2 and 50 N mm–2 and the sodium silicate content of 14 wt.% and 16 wt.%, respectively. It was shown that a porous microstructure of the composite is formed in the course of samples annealing at the temperatures of 600–10000C due to physicochemical processes of transformations of sodium silicate and its interaction with aluminous cement; this porous microstructure is characterized by open porosity in the range of 23.14–25.11% and mechanical strength in the range of 33.2–32.0 N mm–2. The fabricated composite material after its annealing at 10000C shows a low electrical resistivity of 0.06710–2–0.01410–2 Ohmm at the electric current of 28–94 A and the voltage of 19.2–13.2 V.