Polyhydroxybutyrate- Biopolymer ( PHB )

PHB and its copolymers with polyhydroxyvalerate (PHV) are melt-processable semi-crystalline thermoplastics made by biological fermentation from renewable carbohydrate feedstocks. PHB homopolymer is a stiff and rather brittle polymer of high crystallinity, whose mechanical properties are not unlike those of polystyrene, though it is less brittle and more temperature resistant. It has fair acids, alcohols and ultra-violet resistance as well as good greases and oils resistance. Has poor alkalis resistance. Also, its degradation rate is quite high at its normal melt processing temperature. Hence, copolymers are preferred for general purposes. It is believed that the most likely area for the application of homopolymer is in the medical/biological fields.