Swelling of samples of automotive rubber products in standard fluid, engine oil and tribotechnical compound

Abstract

In this paper the change in the properties of rubber products of automobile under the influence of temperatures and when working in an aggressive environment was studied by authors. The radial tire protector samples (Barum 155/70 R13 75T Brillantis 2) with dimensions not exceeding 2×10-2×1.5×-2×5×10-3 [m], seal samples (of 2108-170342-01 type) in the form of a semicircle of 2.7·10-2×7·10-3×2·10-3 [mm] size, both original and aged rubber samples were tested. Aging was carried out in a stream of air, forcibly pumped through the reactor with the rubber placed in it. The heat treatment time was 12-100 hours, the temperature was 70-150 ° C. The change in the properties of rubber was evaluated by the parameter of the change in the mass of the samples (original and aged) after their contact with the liquid. The resistance of rubber to the action of liquids was studied, the kinetics of rubber swelling was studied. As the standard liquid the isooctane (2,2,4-trimethylpentane) was used. The experiments were carried with synthetic engine oil (SEO) “GENESIS CLARITECH” 5W-30 and tribotechnical composition (tribotechnical compounds; TC) “ACTIVE PLUS” (“suprotec”). The use of tribotechnical composition as a test fluid for rubbers was motivated by the purpose of assessing the chemical activity of the “suprotec”, when used in engines operating under conditions of high loads. The kinematic viscosity of SEO and TC was determined (in the temperature range from 20 ° C to 100 ° C) by the HPLC-4 viscometers, the density (ρ) of the liquids was measured with oil-meters. The hardness of the rubber samples was evaluated by measuring the resistance of the rubber by immersion of the indenter (a spring-loaded rod) into it. The indicator of the hour type ICh-02 (accuracy class 0) was used as a gauge.