the present disclosure is directed to polymer blends comprising a biopolymer and one or more impact modifiers , wherein at least one impact modifier is an ester of formula i : and to methods for increasing the impact resistance of a biopolymer with one or more impact modifiers , wherein at least one impact modifier is a ester of formula i . the polymer blends disclosed herein provide impact resistance , and are useful , for example , in the production of packaging materials , industrial products , durable goods , and the like .