The article investigates the influence of technological additives and peroxides on the properties of two rubber mixtures based on ethylene-propylene caoutchouc of marking SKEPT-40. The main properties were: rheometric (maximum and minimum torques; start, optimum and maximum vulcanization rates; maximum vulcanization rates), physical and mechanical (conditional tensile strength, elongation at break, hardness) and operational (changes in conditional strength at tensile, elongation at break and hardness after aging in air). The resistance of rubbers to the action of high temperatures by methods of differential thermal and thermogravimetric analysis was studied. As technological additives, MA-L22, Struktol WS180, Zincolet BB 222 and Struktol A89 were used. Vulcanizing agents were peroxides: Novoperox BP-40, Percodox BC-FF, Dicumyl Peroxide (DK), Chemanox PX1 and Dicumyl Peroxide DCP 99. The studies were carried out for two rubbers, one of which is intended for the manufacture of molded products, and the second rubber – for sealing profiles. It was shown that the technological additive Zincolet BB 222 increases the vulcanization rate of rubber mixture for molded products. All technological additives used have practically no effect on the conditional tensile strength and hardness vulcanizates of molded products, increasing their elongation at break. The smallest changes in the physical and mechanical properties are characterized by the vulcanizate, which contains the technological additive Zincolet BB 222. Technological additives practically do not affect the process of vulcanization of the rubber mixture and slightly affect the process of destruction of rubber during aging. Of the investigated technological additives Zincolet BB 222 is more conducive to improving the thermal properties of rubber. It has been established that Novoperox BP-40 and Chemanox PX1 peroxides increase the rate of vulcanization of the rubber mixture for sealing profiles. For vulcanizates of this rubber mixture, when Novoperox BP-40 and Chemanox PX1 is replaced with other peroxides, a decrease in the conditional tensile strength, hardness and an increase in the elongation at break are observed. With aging in air, changes in the physicomechanical properties of the vulcanizates of the rubber mixture variants containing Novoperox BP-40 and Chemanox PX1 are insignificant and close to each other.

The electrical conductivity of the solutions depends on the nature of the solute and solvent. For a solvent, the main parameter is the dielectric constant. Since the dielectric constant of alcohols is much less than the dielectric constant of water, the electrical conductivity of alcoholic solutions of salts is less than the electrical conductivity of their aqueous solutions. Therefore, alcoholic solutions of inorganic salts are weak electrolytes. We previously studied the electrical conductivity of inorganic salts in a number of alcohols (ethanol, propanol-2 and butanol-1) at room temperature. It is of interest to study the effect of temperature on the electrical conductivity of salts in alcohols. Obviously, an increase of temperature salt solutions leads to an increase in their electrical conductivity. To study the temperature dependence of the electrical conductivity of aqueous solutions electrolytes, we proposed an approach based on the study of the effect of temperature on the equivalent electrical conductivity of solutions at infinite dilution λ∞. Using this approach, we studied the electrical conductivity of aqueous solutions of a number of inorganic salts, carboxylic acids, and amino acids as a function of temperature. It has been established that for these solutions the dependence λ∞(Т) is described by the exponential Arrhenius equation λ∞ = Аexp(-E/(RT)). However, such studies have not been conducted for alcoholic salt solutions. In this regard, this article explores the possibility of describing the experimental data λ∞(Т) for solutions of certain inorganic salts in ethanol by this equation. It is shown that the Arrhenius equation with the found activation energies adequately describes the temperature dependence of the ultimate equivalent conductivity for solutions of a number of inorganic salts (chloride and calcium nitrate, cadmium iodide, lithium and potassium chloride, chloride, iodide and ammonium nitrate, silver nitrate and sodium bromide) in ethyl alcohol.

Earlier, we studied the electrical conductivity of inorganic salts in a number of alcohols (ethanol, propanol-2, and butanol-1) at room temperature and found that alcoholic solutions of inorganic salts are weak electrolytes. It is known that an increase in the temperature of salt solutions leads to an increase in electrical conductivity due to an increase in the mobility of their ions in the solvent medium. To study the temperature dependence of the electrical conductivity of aqueous solutions of electrolytes, we proposed an approach based on the study of the effect of temperature on the equivalent electrical conductivity of solutions at infinite dilution λ∞. Using this approach, we studied the electrical conductivity of aqueous solutions of a number inorganic salts (nitrates, acetates, and phosphates), carboxylic acids, and amino acids as a function of temperature. It was found that for these solutions the dependence λ∞(Т) is described by the exponential Arrhenius equation λ∞ = Аexp(-E/(RT)). This equation was used to describe the temperature dependence of the ultimate equivalent conductivity for solutions of a number of inorganic salts (calcium and nitrate calcium, cadmium, lithium and potassium iodides, chloride, iodide and ammonium nitrate, silver nitrate and sodium bromide) in ethanol. This article investigated and demonstrated the possibility of describing the experimental data λ∞(Т) for solutions of ethylates, propylates and isopropylates of sodium and potassium in the corresponding alcohols (ethylates in ethanol, propylates in propanol, isopropylates in isopropyl alcohol) using the same equation.