| abstract |
A graft polymer is prepared by grafting, onto a polymeric hydrocarbon backbone, a free-radical polymerizable vinyl nitrogen monomer, which grafting takes place in the presence of an aliphatic hydrocarbon substituted aromatic solvent capable of free-radical hydrogen atom chain transfer. The modified hydrocarbon based polymer finds utility as an additive for lubricating oils, particularly as dispersant-viscosity improvers for engine oils. |