Low molecular weight polymethacrylates as multi-functional lubricant additives

Abstract Low molecular weight, moderately polar polymethacrylate polymers are explored as potential multi-functional lubricant additives. The performance of these novel additives in base oil is evaluated in terms of their viscosity index, shear stability, and friction and wear. The new compounds are compared to two benchmarks, a typical polymeric viscosity modifier and a fully-formulated oil. Results show that the best performing of the new polymers exhibit viscosity index and friction comparable to that of both benchmarks, far superior shear stability to either benchmark (as much as 15× lower shear loss), and wear reduction significantly better than a typical viscosity modifier (lower wear volume by a factor of 2–3). The findings also suggest that the polarity and molecular weight of the polymers affect their performance which suggests future synthetic strategies may enable this new class of additives to replace multiple additives in typical lubricant formulations.