INFLUENCE OF SOME ADDITIVES ON THE EFFECINCY OF VISCOSITY INDEX IMPROVER FOR BASE LUBRICATING OILS

The effects of three different additives formulations which are Lubrizol 21001,HiTEC 8722B and HiTEC 340 on the efficiency of viscosit y index improver (VII) namely Olefin Copolymer of three base lubricating oils 40, 60 and 150 stock at four temperatures 40, 60, 80 and 100^o C were investigated.The base oils’ blends were prepared with a concentration range of 2-10 wt% from additives and olefin copolymer (OCP). The results give a noticeable decrease in the kinematic viscosity of the three types of base lubricating oil with increasing temperature.Blending the three base oil types with the H-340 additive shows the maximum
viscosity index (VI) at 2 wt% for 40, 60 and 150 stock. This concentration is helpful in selecting the base oil type and the recommended dosage of H-340 for producing effective and economic automotive gear oil.
The efficiency of OCP (VII) is decreased with an increasing rate when blended with 4 and 8 wt% of Lubrizol 21001 for the three base oil types. But the efficiency is increased when adding 4 wt% of H-8722B in 40 stock and decreased when adding 8 wt%. For 60 and 150 stock the OCP efficiency decreased by adding 4 and 8 wt% of H-8722B.In the other hand, the efficiency of OCP for 60 and 150 stock is decreased with
a high percentage by adding 4 and 8 wt% of H-340. While the efficiency for 40 stock is increased by adding 4 wt% of H-340 and decreased with insignificant percentage when adding 8 wt%.The relative, specific and reduced viscosities were measured to estimate the intrinsic viscosity (IV) for base oils at different weight percent of additives and OCP and at four temperatures (40, 60, 80 and 100^oC). The results indicated that the IV increase with increasing temperatures and concentrations.Finally, a number of VI correlations have been obtained depending on the results predicted in this study. The correlations represent the functional relationships between the VI and the concentration of OCP for three types of base lubricating oil and for each type of additives.