SEARCH Articles Figures Tables Copolymers polyhydroxybutyrate-valerate POLYHYDROXYBUTYRIC Polyhydroxybutyrate Polyhydroxybutyrate-valerate biodegradability Polyhydroxybutyrate-valerate blends Polyhydroxybutyrate-valerate copolymers PHBV) Polyhydroxybutyrates Valeral Valerate Valerates Valeric