聚己内酯－聚乙二醇嵌段共聚物Ⅱ．组成、结晶性同降解性间关系

POLYCAPROLACTONE-POLY(ETHYLENE GLYCOL) BLOCK COPOLYMER Ⅱ. RELATIONSHIP AMONG COMPOSITION,CRYSTALLINITY AND DEGRADABILITY

采用ＤＳＣ法测定了新嵌段共聚物聚己内酯（ＰＣＬ）－聚乙二醇（ＰＥＧ）嵌段共聚物（ＰＣＥ）的结晶性，研究了共聚物的结晶性同组成及降解性的关系．结果表明随着共聚物中ＰＥＧ组分的含量和分子量增加，共聚物的结晶性下降，亲水性提高，降解速度加快．

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. reduHydrophilicity of the PCE copolymer was increased with increasing the content and the molecular weight of the PEG component. Degradation rate of the PCE copolymer was identified by hydrolysis reaction.As a result the degradation rate of the PCE copolymer increased with introducing PEG component,that the degradation rate increased with reducing the crystallinity and increasing the hydrophilicity of the copolymer.