杂化共聚合成功能性支化共聚酯

Aliphatic polyesters, the so-called green materials in the new century, have broad applications in the fields of agriculture, medicine, anti-fouling and package due to their good biocompatibility and degradability. The induction of functional groups and branched structures will promisingly enhance their properties. However, the hyperbranched polyesters are only prepared via polycondensation or ring-opening polymerizations, in which functional groups are hard to be introduced. Moreover, the monomers used for polymerization should be synthesized through multi-step tedious reactions. The hybrid copolymerization is one kind of new polymerization, by which two different monomers, cyclic monomers and vinyl monomers, were copolymerized. In this program, we attempted to hybrid copolymerize the ε-caprolactone (CL) with the commercial inimer for facile syntheses of the hyperbranched polyester. the basic idea of inimer originated from living self-condensation polymerization of vinyl inimer. Here, hydroxyl and vinyl group is the initiative and polymerizable unit respectively. The polymerization behavior and branched topology of the copolyester will be characterized by gas chromatography (GC), the nuclear magnetic resonance (NMR), the triple detection size exclusion chromatography measurements (TD-SEC), and light scattering (LS). Then, we try to hybrid copolymerize functional monomer, methacrylate butyl hexafluorophosphate, with CL, and obtained hyperbranched copolyester with low surface energy. The properties of the synthesized polymers are characterized by quartz crystal microbalance with dissipation (QCM-D) and biotic experiment.

脂肪族聚酯具有良好的生物相容性和降解性，在农业、医药、防污、包装等领域有广泛应用前景，被称为新世纪的绿色材料，引入功能基团和支化可望进一步改善其性能。目前脂肪族支化聚酯主要由缩聚和开环聚合合成，因功能单体和支化单体均需经繁琐过程制备，所以难于合成功能性支化共聚酯。杂化聚合是一种新型聚合反应，它实现了环状单体与乙烯基单体两类不同单体的共聚合。本项目借鉴引发剂单体自缩合乙烯基活性聚合反应合成乙烯基支化聚合物的思想，以商品化（甲基）丙烯酸羟乙酯为引发剂单体：其中羟基为引发单元、双键为聚合单元，与己内酯和乙烯基单体杂化共聚；用GC、NMR、TD-SEC和LS研究共聚反应行为及共聚酯的支化形态，建立一步合成功能性支化共聚酯的简易方法。以甲基丙烯酸六氟丁酯为功能性共聚单体，探索合成具有低表面能和生物降解性双重功能的功能性防污支化共聚酯。用细胞实验、表面张力仪、QCM-D等手段评价其防污性能。

脂肪族聚酯具有良好的生物相容性和降解性，在生物医药相关领域有重要的应用前景。通常，脂肪族聚酯可由内酯的开环聚合制备。但是，由于内酯的种类有限，合成的聚酯结构单一，无功能基团可用于后续改性，极大限制了脂肪族聚酯的发展。本项目以杂化聚合为方法支撑，一方面从聚合物化学结构出发进行分子设计，通过研究己内酯与N-苯基马来酰亚胺的杂化共聚反应、己内酯与甲基丙烯酸二甲氨基乙酯的杂化共聚反应、己内酯和甲基丙烯酸六氟丁酯的杂化共聚反应，制备了一系列可降解功能性共聚酯；并用核磁、凝胶渗透色谱、红外光谱、差示扫描量热仪以及热失重仪等对聚合物结构及聚合反应过程进行了详细研究。另一方面，从聚合物链结构出发进行结构设计，将自缩合乙烯基聚合的概念应用于杂化聚合，用商品化单体甲基丙烯酸羟乙酯为自引发单体分别引发己内酯与甲基丙烯酸甲酯、己内酯与甲基丙烯酸烯丙酯、己内酯与甲基丙烯酸六氟丁酯以及己内酯与甲基丙烯酸二甲氨基乙酯的杂化共聚反应，制备了系列可降解超支化聚酯；并对聚合物的降解性能、低表面能性能等进行了研究。本项目最大特点是从商品化的原料出发，在温和的反应条件下制备了含多种官能团的可降解聚酯，建立了一步合成功能性脂肪族支化共聚酯的简易方法，因此具有理论和实际应用价值。