Lubricating Oil Compositions
A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight, based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit: -N(COR1)CH2CH2-wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerization terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerization of linear,branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R1 in the polymer comprises alkenyl groups having between 15 and 20 carbon atoms.