Synthesis, properties and in vitro degradation of carboxyl-bearing PCL

Aliphatic polyesters derived from lactic and glycolic acids (PLAGA) are the most attractive degradable polymers with respect to biomedical and environ mental applications.Poly(-epsilon -caprolactone), PCL, is a hydrophobic hig hly crystalline aliphatic polyester that is more resistant to hydrolytic de gradation than PLA. It is not biodegradable in animal body but is rapidly d egraded by outdoor microorganisms. In order to increase the rate of hydroly sis of the material, carboxyl-bearing PCL copolymers (PCLCOOH) were synthes ized by anionic activation with LDA and reaction of CO2 on the polycarbanio n. Variations in crystallinity, thermal properties and hydrophilicity cause d by the presence of the pendent carboxyl groups were investigated. The deg radation behavior of PCLCOOH was assessed by the evaluation of water uptake , mass loss, molecular masses and ESEM microphotographs. A dramatic increas e in the hydrolytic degradation rate was observed compared with pure PCL, t hus PCLCOOH can now be considered as a hydrolytically degradable polymer.