A graft copolymer containing one or more ethylenically-unsaturated, aliphatic or aromatic, nitrogen- and oxygen-containing graftable monomers grafted to a polyolefin is disclosed. Novel monomers, methods of making such monomers, and graft copolymers comprising such monomers are based on reacting an acylating agent with an amine to form a reaction product. The reaction product may include more than one chemical compound formed from the combination of the acylating agent and the amine. The monomer is the graftable, ethylenically unsaturated, aliphatic or aromatic, nitrogen- and oxygen-containing compound(s) of the reaction product. The monomer may, but need not, be recovered from the product mixture. The preferred monomer is the reaction product of maleic anhydride and 4-aminodiphenylamine. Also described is a method of making a dispersant viscosity index improver. The monomer of the present invention may be grafted to a polyolefin in solutions or melts. Also described is a lubricating oil comprising a base oil and a grafted polyolefin as described above.