中文摘要：

合成了末端均为羟基的聚丁二酸丁二醇酯（PBS）预聚物，再以PBS的端羟基引发D-丙交酯（D—LA）开环聚合，得到聚右旋乳酸（PDLA）与PBS的三嵌段共聚物（PDLA—PBS—PDLA）．通过凝胶渗透色谱和核磁共振氢谱进行了结构表征．随着m（D—LA）：m（PBS）由0．51：1逐渐增加至2．60：1，PDLA—PDS．PDLA中PDLA链段的长度逐渐增加．随着PDLA嵌段长度的增加，PDLA嵌段对PBS嵌段的限制作用增强，并导致PBS嵌段结晶温度下降，结晶焓降低．当m（D—LA）：m（PBS）=2．60：1时，PBS嵌段不再能形成结晶．而m（D—LA）：m（PBS）在0．51：1～3．04：1范围内，PDLA嵌段均可形成结晶，PDLA嵌段的熔点随其在嵌段共聚物中含量的增加而逐渐升高，但PDLA嵌段的熔融焓呈现先增加后降低的趋势．在部分嵌段共聚物中，PBS和PDLA嵌段可各自形成结晶，且PBS和PDLA的结晶结构不随组分的变化而发生改变，表明该嵌段共聚物中PDLA嵌段和PBS嵌段呈微相分离结构．

英文摘要：

Poly （D-lactide） -poly （ butylene succinate ） -poly （D-Lactide） （PDLA-PBS-PDLA） was synthesized by the ring-opening polymerization of D-lactide（D-LA） in the presence of Sn（ Oct）2 and the pre-polymerized PBS as the macro-initiator. The PDLA-PBS-PDLA tit-block polymers were confirmed by gel permeation chromatography （ GPC ） and nuclear magnetic resonance （ ~ H NMR）. Results of differential scanning calorime- ter（DSC） and X-ray diffraction （XRD） revealed that with the increase of Mn of PDLA blocks, the melting temperature and enthalpy of PBS blocks decreased, and the crystallites of PBS blocks could not be detected by DSC when m（D-LA） ： m（PBS） was set as 2.60 ： 1. For all the samples, PDLA segment could crystallize. With the increase of the amount of PDLA in the copolymers, the melting temperature of PDLA blocks increased gradually, but the melting enthalpy of PDLA blocks increased first and then decreased. Further- more, both PDLA and PBS blocks could crystallize separately, and the crystal structures PDLA and PBS blocks did not change with m （D-LA） ： m （PBS） copolymers. , which revealed that the microphase separation formed