Biodegradable and hydrodegradable diblock copolymers composed of poly(. beta.

摘要

A biodegradable and hydrodegradable diblock copolymer includes a naturally-occurring poly(&bgr;-alkanoate) component and a chemically synthesized polyester component formed by ring-opening polymerization. A method of forming the biodegradable and hydrodegradable diblock copolymer having a poly(&bgr;-hydroxyalkanoate) component and a chemically synthesized polyester component includes exposing a naturally-occurring poly(&bgr;-hydroxyalkanoate) to alcoholysis and then to a trialkyl metal to form a dialkyl metal poly(&bgr;-hydroxyalkanoate) macroinitiator. The macroinitiator is then reacted with a lactone or lactide reactant to form the biodegradable and hydrodegradable diblock copolymer.