Biologically Produced (R)-3-Hydroxy- Alkanoate Polymers and Copolymers

摘要: Microorganisms are capable of producing a wide range polymers and copolymers based on 3-hydroxypropionic acid substituted with various alkyl groups in the 3-position. The most common homopolymer is poly (3-hydroxybutyrate), PHB, which has 3-methyl substituent, but monomers having C2-C5 side found natural copolyesters. all optically active r absolute configuration. Phb can be produced from carbon substrates as diverse glucose, ethanol, acetate, methane even gaseous mixtures dioxide hydrogen. polymer occurs discrete granules within cell cytoplasmic space represent up to 80% dry weight. After extraction purification it behaves normal crystalline thermoplastic melting point around 180°C processed by conventional extrusion moulding equipment. PHB its 3-hydroxypentanoic now available commercially being evaluated numerous potential applications. genuinely biodegradable that their rate chemical hydrolysis extremely slow microorganisms produce both specific non-specific esterase enzymes degrading materials rapidly non-toxic monomers. Most uses exploit this property medical, veterinary, horticultural general disposable products.