THE INFLUENCE OF BIOCARBON ADDITIVES ON GREASE FUNCTIONALITY

The article presents the results of tests on tribological and physicochemical properties of plastic greases, in which the dispersing phase was highly refined mineral oil and the dispersed phase (thickener) lithium stearate. The functional additives were biocarbon, which were obtained in the pyrolysis process of waste of natural origin, i.e. stems with corn leaves, wheat straw, flax straw, and cherry stones. The compositions containing 5% m/m biocarbon were prepared. Their evaluated on the functional properties of plastic greases was assessed. Tribological characteristics of the greases compositions were determined using the T-02 tester in accordance with the requirements of the subject standards. The effect of biocarbon used on anti-wear (Goz) and anti-seizing (Pt, poz) plastic greases was determined. An assessment was also made of the effect of plant biocarbon on changes in basic physicochemical properties of the composition of plastic greases, i.e. penetration, dropping temperature, and thermo-oxidative stability. It was found that some of the biocarbon significantly improve the tribological properties of plastic greases without significantly affecting the change of key physicochemical parameters. The most beneficial impact of the tested additives on the operational properties of plastic greases was observed when using biocarbon from wheat straw. In some cases, a lower oxidative resistance of biocarbon grease is observed compared to grease without the addition of biocarbon.