Base Effects on Carbonylative Polymerization of Propylene Oxide with a [(salph)Cr(THF)2]+[Co(CO)4]- Catalyst

Poly (3-hydroxybutyrate) (PHB) is a naturally occurring biodegradable and biocompatible polyester and considered as a class of potentially thermoplastic biopolymers in industry. The alternating copolymerization of cheap and available propylene oxide and carbon monoxide may be an efficient synthetic route for PHB. Here, we studied the base effects on the synthesis of PHB using a well-defined [(salph)Cr(THF)(2)](+)[Co(CO)(4)](-) catalyst combined with various bases. It was found that base not only affects the yield of PHB, but also the molar ratio of each unit in the product.