Effect of Functional Additives on Performance of Internal Combustion Engine Lubricating Oil

Abstract

In order to improve the quality of lubricants and prolong the life of oil products, additives should be added to the base oil. The non-functional additives of lubricating oil are mainly included: viscosity index improver, pour point depressant, anti-foam agent. In a certain ratio, the viscosity index improver, pour point depressant, and anti-foam agent have a synergistic or inhibitory effect. This experiment aims to explore the synergistic and inhibitory effects of non-functional additives and the effect of different dosage of additives on the performance of internal combustion engine lubricants. Certain amount of additives are added to the base oil for testing. Viscosity index improver T613, pour point depressant T803B, anti-foam agent T901 were selected as non-functional additives in the experiment. An orthogonal experiment was used to design the scheme. The performance of compound non-functional additives on lubricating oil was determined by means of oil kinematic viscosity measurement, foam property measurement and petroleum pour point measurement. The results of orthogonal design show that: the addition of anti-foaming agent is in the range of 5–20 ppm/100 g, and the viscosity index improver is inhibited. When the pour point depressant is 0.2–0.3 wt%, it has synergistic effect with viscosity index improver, but more than 0.3 wt% after the viscosity index improver to produce inhibitory effect. The anti-foaming agent content has a synergistic effect on the pour point depressant in the range of 5–20 ppm/100 g; the viscosity index improver has a synergistic effect on the pour point depressant in the range of 5–6.5 wt%. The content of the pour point depressant in the range of 0.2–0.3 wt% synergies with the anti-foaming agent, the content of more than 0.3% after the inhibition effect; adding viscosity index improver in the range of 5–6.5 wt% with the anti-foam agent inhibition. The optimum process was as follows: viscosity index improver T613 was 6.0 wt%, pour point depressant T803B was 0.3 wt%, and anti-foam agent T901 was 5 ppm/100 g.