the present invention refers to a polymeric blend for the preparation of environmentally degradable materials , said blend comprising biodegradable polymers , polyhydroxybutyrate — phb or copolymers thereof and poly aliphatic - aromatic copolyester and at least one additive . the present invention further refers to the process for obtaining said blend , by applying the extrusion technique to obtain an adequate morphology in the distribution , dispersion and interaction of the polymers , so as to obtain compatible polymeric blends , allowing the granules of the produced polymeric blends to be utilized to manufacture several injection molded products .