| abstract |
The present invention provides polymers comprising polymerised blocks of a hydrogenated conjugated diene (B), a vinylarene (A), and a methacrylate (M) or an amide or imide derivative thereof, wherein the polymer is a mixture of first molecules having a polymerised block structure B-A-M and second molecules having a coupled block structure B-A-M-A-B; a process for their preparation; lubricating oil compositions containing them; and their use as viscosity-index improver additives. |