Compositions are described that are blends of a grafted copolymer and a polyamide. Methods of making the blended compositions are also described. The grafted copolymers are the reaction product of (1) a first compound having both an aziridinyl group and a polymeric group with (2) a second polymeric material having an acidic group. Blending the grafted copolymer with the polyamide can be used, for example, to increase the cohesive strength of the grafted copolymer.