A composition comprising a blend of a polyolefin, polylactic acid, and a reactive modifier. A method of producing an oriented film comprising reactive extrusion compounding a mixture comprising polypropylene, polylactic acid, a reactive modifier to form a compatibilized polymeric blend, casting the compatibilized polymeric blend into a film, and orienting the film. A method of preparing a reactive modifier comprising contacting a polyolefin, a multifunctional acrylate comonomer, and an initiator under conditions suitable for the formation of an epoxy-functionalized polyolefin wherein the epoxy-functionalized polyolefin has a grafting yield of from 0.2 wt. % to 15 wt. %.