he relationship among composition

crystallinity and degradability of Polycaprolactone(PCL)-Poly(ethylene glycol)(PEG)block copolymer PCE)has been studied by means of DSC and X-ray diffraction techniques. It was found that the crystallinity of the PCE copolymer has closely depended on both the molar ratio of caprolactone(CL)unit to ethylene glycol(EG)unit(CL/EG)

and the molecular weight of the PEG component

that is the crystallinity of PCE copolymer reduced with increasing either the content or molecular weight of the PEG component.Hydrophilicity of the PCE copolymer was increased with increasing the content and the molecular weight of the PEG component. Degradation rate of the PCE copoly-mer was identified by hydrolysis reaction. As a result the degradation rate of the PCE copolymer increased with introducing PEG component

that the degradation ra-te increased with reducing the crystallinity and increasing the hydrophilicity of the copolymer.