Grafted compounds are formed by reacting (1) a first compound having both an aziridinyl group and a polymeric group with (2) a second compound having at least one acidic group. This reaction results in the opening of the aziridinyl ring on the first compound by the acidic group on the second compound and the formation of an attachment group that connects polymeric group of the first compound to the second compound. In some embodiments, the second compound is a polymeric material having multiple acidic groups and the product of the reaction of the first compound with the second compound results in the formation of a grafted copolymer.