本课题研究结构明确的聚醚酯多嵌段交替共聚物的合成、表征及结构和性能的关系。采用聚醚二醇和环状寡聚酯单体熔融聚合，通过开环-缩合聚合方法，制备结构明确的聚醚酯多嵌段交替共聚物，解决现有的聚醚酯弹性体无规聚合方法导致的结构不明确的问题；研究各种环状寡聚酯在"假高稀"条件下的合成方法；建立利用定量核磁技术结合二维核磁技术，通过端基分析和官能团分析方法，对多嵌段共聚物的结构如共聚物的总分子量、各嵌段分子量和嵌段数目等进行分析的方法；研究聚酯硬段和聚醚软段的化学结构、含量、分子量、以及嵌段数目等对共聚物性能的影响，重点研究对断裂拉伸率、拉伸应力、模量、回弹性能等弹性体性能的影响，总结结构和性能的关系，并指导聚醚酯共聚物的设计，合成出高性能聚醚酯弹性体；研究具有其他性能的多嵌段聚醚酯弹性体的合成；研究多嵌段交替共聚物作为一种软硬多嵌段交替共聚物在选择性溶剂中的自组装性能。

The object of this proposal is to study the synthesis, characterization, and properties of structure-known poly(ether ester) alternative multiblock copolymers. By the melt polymerization of polyether diols and cyclic oligoesters, the ring-opening polymerization followed with condensation polymerization method, is utilized to synthesize the poly(ether ester) alternative multiblock copolymers. This method can resolve the current problem in the synthesis of poly(ether ester) elastomers, where the random condensation copolymerization method produces random copolymers with unclear structure. The reaction conditions for the synthesis of cyclic oligoesters under "psuedo high dilution" condition will be studied. The characterization method to estimate the multiblock copolymers' chemical structure, including the whole molecular weights, the content of each block, the block and segment length, and segment repeating units, will be established by using the quantitive 1H NMR and two-dimensional NMR. The influence of chemical structure, content, molecular weights and segment repeating units from the polyester hard segments and polyether soft segments, on the properties of multiblock copolymers will be studied, especially the elastomer properties including the break elongation and stress, the modulus and the recovery. The structure-property relationship will be established, and used to instruct the design and synthesis of poly(ether ester) elastomers with good properties. The synthesis of alternative multiblock copolymers with special function and their properties will be studied. As a kind of special rod-coil alternative multiblock copolymers, the self-assembly of poly(ether ester) alternative block copolymers in selective solvents will be studied.