poly(3-hydroxybutyrate)

Poly(3-hydroxybutyrate), or PHB, is a naturally derived polyester and the most common member of the polyhydroxyalkanoate (PHA) family, produced through bacterial fermentation or synthesized chemically. It is a brittle, crystalline bioplastic notable for being fully biodegradable and compostable in industrial and marine environments, making it a key alternative to petroleum-based plastics where environmental persistence is a design liability. PHB sees use in packaging, agricultural films, and medical devices, though it is less common than PLA in commercial applications due to higher material costs and brittleness; engineers select it specifically when complete biodegradation within a defined timeframe, biocompatibility, or reduced fossil fuel dependency are project requirements.