wherein R1 is the residue of a group having at least 2 active hydrogen atoms; m is at least 2; AO is an alkylene oxide residue; each n is independently from 0 to 100; and each R2 is independently H or R3, where each R3 is independently a residue of a polyhydroxyalkyl or polyhydroxyalkenyl carboxylic acid, a residue of a hydroxyalkyl or hydroxyalkenyl carboxylic acid and/or a residue of an oligomer of the hydroxyalkyl or hydroxyalkenyl carboxylic acid; and on average at least 0.5 of R2 groups are R3. The lubricant composition is suitable for use in an engine oil, a hydraulic oil or fluid, a gear oil and/or a metal-working fluid.