乙酰丙酮锆催化乙丙交酯开环共聚的工艺研究

摘要

Poly(glycolide-co-lactide) (PLGA) with a range of molecular weight was synthesizedvia a new method of copolymerization of glycolide with L-lactide by using zirconium(Ⅳ) acetylacetonate [Zr(Acac)4] as initiator. The properties and structure of PLGA were characterized by NMR spectroscopy,differential scanning calormetry (DSC),thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The crystallinity of copolymers obtained was higher than that formed in the presence of traditional catalyst Sn(Oct)2. The effects of catalyst dosage,polymerization temperature and time were investigated. The optimal condition was as follows:zirconium(Ⅳ) acetylacetonate 0.06%,polymerization temperature 150℃,polymerization time 6h. Intrinsic viscosity of PLGA could reach 0.957dL/g and average molecular weight could reach 1.24×105.%以乙酰丙酮锆[Zr(Acac)4]为催化剂引发不同配比的乙交酯和L-丙交酯开环共聚反应，合成出了系列分子量的聚乙丙交酯（PLGA）。采用核磁共振（1H NMR）、差示扫描量热（DSC）、热重分析（TGA）和X射线衍射（XRD）等方法表征了PLGA的结构和性质。结果表明，以乙酰丙酮锆催化制备的PLGA结晶度高于由传统催化剂辛酸亚锡制备的PLGA。研究了催化剂用量、聚合温度、聚合时间对聚乙丙交酯（PLGA）特性黏度的影响，得出了较优的反应工艺条件为：乙酰丙酮锆用量为0.06%，聚合温度为150℃，聚合时间为6h，合成了特性黏度达0.957 dL/g、重均相对分子质量为1.24×105的高分子量的PLGA。