The novel polymers of the present invention are prepared by graft polymerization of at least one aromatic nitrogen-containing monomer onto an amino-substituted polymer (e.g., an ethylene alpha-olefin interpolymer substituted by primary amino or secondary amino groups). Preferred aromatic nitrogen-containing moieties are illustrated by aniline, and preferred amino-substituted interpolymers comprise amino-substituted ethylene propylene norbornene terpolymers. The polymers of this invention are oil soluble and are useful as dispersant and antioxidant additives in oleaginous compositions and are further useful in electrical, textile and other applications.