OIL-SOLUBLE ANTIOXIDANT POLYMETHACRYLATES FOR LUBRICANTS

The evaluation of oil soluble, antioxidant bound polymethacrylates use d as viscosity index improver lubricant additives, is described herein . They were synthesized by copolymerization of the antioxidant-dispers ant monomer and alkyl methacrylates. Oxidative stability was determine d by oxidative pressure differential scanning calorimetry, thin film o xidation uptake test and aluminum beaker oxidation text. These tests s how that lubricants containing these polymers show performance advanta ges over commercial polymethacrylates, with additional benefits in oth er viscometric properties such as shear stability and Brookfield visco sity. The antioxidant monomer also serves as a dispersant moiety, thus improving the polymer dispersancy. Binding the antioxidant to the pol ymer ensures the solubility of the antioxidant while eliminating the p ossibility of its volatilization in high temperature environments. The current results suggest that antioxidant-dispersant polymethacrylates have excellent potential as additives in lubricants such as automatic transmission fluids.