Experimental investigation of sealing rubber property at high and low temperatures

In the nodes of aerospace engineering fixed and movable seals made from rubber are widely used. It is also known that the operation of nodes of rocket and space technology comes in a very broad range of both low and high temperatures. Therefore, the calculations of fixed and movable seals of such nodes depending on the elastic constant temperature and temperature effect on the coefficient of friction of rubber must be considered. Otherwise emergence of leaks through seals is possible at low temperatures, and at high temperatures there can be its destruction. The technique studies flexural modulus of the rubber samples in a wide range of temperatures and the bending deformation. The technique of the coefficient of friction of rubber research in friction against steel and fluorine-containing coatings at low and high temperatures is given. Friction coefficients were defined at a one-way rotary motion of flat samples at a speed of sliding of 0.2 m/s and pressure upon friction surfaces from 0.8 to 50 MPa and the range of temperatures from - 40 to 120 °C. The temperature dependences of the static elasticity module at a bend in the range from - 70 to 100 °C for five compositions of butadiene-nitrile rubbers are established as a result of experimental studies. Also results of the temperature test imitating change of contact stress in seal after installation at 20 °C and the subsequent cooling, and also temperature test, when after cooling deformation of a bend is increased, are given. The temperature dependences of friction coefficient rubber on fluorinated coverings of three types and steel in the wide range of negative and positive temperatures are experimentally received.