离聚物的分子结构对离子聚集体结构与离聚物性能具有决定性作用，目前关于脂肪族聚酯离聚物分子结构设计、离子聚集体结构与离聚物性能调控的研究仍是空白。本项目以聚丁二酸丁二醇酯（PBS）基离聚物为研究对象，设计合成三种不同分子结构的PBS基离聚物，通过对离子基团分布与离聚物主链结构的调节，进行离子聚集体结构与离聚物性能的调控。具体而言拟合成PBSI无规离聚物、PBS-b-PBSI与PBS-b-PESI多嵌段共聚酯离聚物三种不同分子结构的离聚物；通过对PBS基离聚物的分子结构与离子聚集体结构关系的研究，与分子结构及其对应的离子聚集体结构对离聚物熔体性质、力学性能、热性能、结晶性能、亲疏水性与降解性能等影响的深入研究，揭示分子结构对离子聚集体结构与PBS基离聚物性能的影响规律，掌握脂肪族聚酯离聚物性能调控的关键技术，为该类材料的应用提供理论与技术支持。因此，本项目兼具科学意义与应用价值。

Ionomer is a polymer with small amount of ionic groups (usually less than 10%) attached to the backbone of polymer chain. It is well-known that such ionic groups tend to form phase-separated ionic aggregates in the hydrophobic polymer matrix. The ionic aggregates act as physical crosslinks which could improve the melt viscosity, melt strength, mechanical strength and toughness of polymer matrix significantly. The structure of ionic aggregate plays an important role in the properties of ionomer. The structure of ionic aggregate depends strongly on the structure of ionomer. There are some reports on the molecular design and property regulation of traditional vinyl ionomers. Aliphatic polyesters such as poly(butylene succinate) (PBS) are regarded as the most promising biodegradable polymers, due to their thermal stability, mechanical strength, and relatively high melting temperature. They can be widely used to replace non-degradable conventional plastics in general purpose application. However, aliphatic polyesters also have disadvantages. Taking PBS as an example, the melt strength and tear resistance are very poor, and the biodegradation rate is very small. Those shortcomings restricted the application of PBS significantly. PBS based ionomer has been reported in recently literatures, but only random PBS ionomer was synthesized and investigated. No report has been reported on the molecular design and property regulation for biodegradable aliphatic polyester ionomer, although the molecular structure of ionomer determines the ionic aggregate structure thus the properties of ionomers. In this project, we plan to synthesize high-molecular-weight PBS based ionomers with designed structures via chain-extension reaction. We designed three ionomers, i.e., PBSI random ionomer, PBS-b-PBSI multiblock copolyester ionomer, and PBS-b-PESI multiblock copolyester ionomer. The three ionomers will be synthesized by chain extension reaction of corresponding hydroxyl terminated prepolymers with hexamethylene diisocyanate as a chain-extender. Through molecular design, the distribution of ionic group on polymer chain and thus the structure of ionic aggregate can be regulated, and consequently, the comprehensive properties of PBS can also be tailored. The effect of molecular structure on the ionic aggregate structure and the melt behavior, thermal and mechanical properties, crystallization behavior, and biodegradation behavior of PBS based ionomers will be investigated systematically. The structure-property relationship of PBS based ionomers will be finally established. The results of the project are expected to enrich the basic principle of aliphatic polyester ionomers. In addition, a new biodegradable material with controllable properties is anticipated after the investigation of the project. Therefore, the project is meaningful not only theoretically but also practically.