EFFECTS OF FLUORORGANIC COMPOUNDS ON PHYSICAL-AND-MECHANICAL PROPERTIES OF RUBBER FOR MANIFOLD SEALS OF FARM MACHINERY

Abstract

The paper gives account of the properties of rubber modified with organofluorine compounds (OC). Additives of various molecular weights, designated FS-1 and FS-2, have been chosen for this purpose. They have been introduced into the rubber composition of ИРП (IRP) 1068 used for the production of sealing cups, in an amount of 1 weight part per 100% weight parts of rubber. It has been established that the OC introduction leads to a certain increase in tensile strength and relative tensile elongation. The hardness of rubbers has not practically changed. The resistance of rubbers to heat aging has been noticeably improved by such factors as tensile elongation and resistance. The relative residual deformation of compression with the OC introduction practically has not changed. For rubber with the FS-2 additive, the resistance to abrasion has increased. Frictional tests have been carried out using a face friction machine and a bench simulating the performance of seals in real operating conditions. It has been established that the OC introduction in the rubber composition leads to a decrease in the coefficient of friction. At the same time, the frictional force decreases in the initial period of shearing the contacting surfaces, especially for rubber containing FS-2. The steady-state friction is also reduced for sealing cups made of rubbers containing organofluorine compounds, as compared to unmodified sealing cups. The results obtained indicate a greater efficacy of FS-2 introduction. It can be assumed that the lesser degree of the additive volatility is the determining factor for reducing the friction force, as evidenced by the large molecular weight and the boiling point of FS-2. It has been established that OS are able to improve the performance properties of sealing cups used in agricultural machinery.