OPTIMIZATION OF CONCENTRATION OF ANTIOXIDANT ADDITIVE IN PLASTIC LUBRICANT BASED ON RAPESEED OIL

Plastic lubricant with rapeseed oil dispersion medium is considered with addition of diphenylamine antioxidant additive. Analysis of tribotechnical, chemical and physicо-mechanical characteristics of the obtained lubricants with content of antioxidant additive from 0.5 to 10.0 wt.% is carried out. The effect of the additive concentration and temperature of introduction on the functional characteristics of lubricants is shown. A comprehensive method is proposed for evaluating the optimal concentration and temperature of the antioxidant additive introduction using an integral indicator, according to the lubricant total functional characteristics. It is noted that for plastic lubricant with a rapeseed oil dispersion medium and a dispersion phase based on a complex calcium thickener, the optimal temperature range for introducing an antioxidant additive is 85–95 °C at the cooling stage, at a concentration of 1.0 wt.%. In this case, the best combination of the finished product functional characteristics is achieved. Based on the proposed methodology and taking into account the experimental data, using expert criteria it is possible to optimize the concentration and temperature of introduction of antioxidant additive diphenylamine, to obtain a plastic lubricant with given characteristics.