The Influence of Molecular Weight of Polyisobutylenes on Tribological Properties of Polyurea Greases

The purpose of this work was to investigate the effect of a thickening polymer additive - polyisobutylene - on tribological properties of polyurea greases. Biocoal in concentration of 5,10,15 mas. % was added to the obtained lubricant samples. The following were analyzed: dropping point (GOST 32394-2013), penetration (GOST 32331-2013), colloid stability (GOST 7142-74) and tribological characteristics (GOST 9490-75). Based on the analysis of the data obtained, it was concluded that the diameter of the wear spot decreases and the dripping temperature increases with increasing concentration of the filler, which affects the effectiveness of its work in the grease. To improve the studied parameters it was suggested to add to dispersion medium a thickening additive - polyisobutylene (PIB) of different molecular weight -10 thousand g/mol, 30 thousand g/mol and 50 thousand g/mol (1%). As a result of the work performed, we concluded that the best tribological properties are the samples in which an PIB additive of 10 (1%) was dissolved in oil.