Investigation on the dispersancy performance of several kinds of lubricants by using low-temperature oxidation-sludge apparatus

The behaviors of dispersancy of a number of engine oils and some dispersants added in mineral oil were tested by using a self-made low-temperature oxidation-sludge apparatus (LTOSA) at 130°C with 10% catalyst (mass fraction) 4.5% NO_x in the water saturated air for 8 hours. The LTOSA results show that (1) superior engine-oils exhibit the better dispersancy performance; (2) adding more amount of dispersants in the mineral oil gives smaller LTOSA indices; (3) Among the tested dispersants of succinimides, ester ashless dispersants and di-anhydride ashless dispersants, the monosuccinimide shows the best dispersancy performance. The results also show that the LTOSA method under the selected conditions is very effective in investigating the dispersancy of lubricants or additives.