Biodegradable aliphatic polyesters such as poly(glycolide) (PGA)

poly(L-lactide)(PLA)

poly(ε-caprolactone) (PCL) and their copolymers have been found widely applications in sutures

tissue engineering

bone fixation and controlled drug delivery due to their excellent biocompatible and biodegradable properties.But the shortage of functional pendant groups and low hydrophilicity limited their further applications.In this work

we explored a synthetic strategy of aliphatic polyesters functionalized with the pendant carboxylic groups through the ring-opening polymerization of novel functionalized lactone.First

2-ethoxycarbonylmethyl-cyclohexanone was synthesizedvia nucleophilic addition.Second

6ethoxycarbonylmethyl-ε-caprolactone(ECL) was generated by the Baeyer-Villiger oxidation of the 2-ethoxycarbonylmethylcyclohexanone.Then

homopolymer and copolymers were accomplished in bulk (130℃) by ring-opening polymerization in the presence of stannous 2-ethyl hexanonate Sn(Oct)2) as catalyst.All the polymers were characterized by FTIR

1H-NMR

13C-NMR

GPC

and DSC.The melting temperature (Tm) decreased with an increase of ECL content because the molecular weight decreased in corresponding.It was also noted that ΔHm for copolymers increased with an increase in the molecular weight because the relative number of copolymer chain ends and pendant functional groups decreased with a decrease of content of ECL.We think the availability of pendent groups on poly(ε-caprolactone) has great potential for applications in medicine

surgery

and tissue engineering.