【作者】 张楠楠；

【导师】 杨青芳；

【作者基本信息】 西北工业大学 ， 材料学， 2007， 硕士

【摘要】 论文对乙交酯、丙交酯的合成进行了详细研究，获得了高纯度的单体；在此基础上通过二单体的共聚得到聚乙丙交酯(PLGA)，探讨了共聚条件对最终产物结构及性能的调控机理，为PLGA的实用化奠定初步基础。 首先，文中通过正交实验对乙交酯的合成条件进行了研究，考察了催化剂种类(辛酸亚锡、三氧化二锑)及用量、反应时间、反应温度等因素对产物收率的影响，并采用红外光谱(FT-IR)、差示扫描量热仪(DSC)、X射线衍射仪(WAXD)及核磁共振技术(~1H-NMR)对产物的结构进行了详细表征。结果显示，在催化剂氧化锑用量为0.8g，脱水条件为110～130℃／2h，齐聚条件为180℃／4h，解聚条件为260～280℃时，乙交酯的产率较高；通过三次重结晶之后，可以得到较高纯度的乙交酯。 另外，以乳酸为单体，采用先缩聚后解聚的方法制备了L-丙交酯。先通过正交实验系统的研究了合成工艺，包括三种不同催化剂(锌粉、乙酸铜及辛酸亚锡)用量、脱水温度及裂解温度对产物收率的影响，进而考察了提纯方法对丙交酯最终产率及杂质(乳酸、水)含量的影响，并利用FT-IR、DSC及~1H-NMR技术对产物结构进行了详细表征。结果发现，在辛酸亚锡催化下，脱水及裂解温度分别为130℃及190℃时，L-丙交酯单体的产率达到80％；通过四次重结晶可以得到较高纯度产物。 最后，采用内酯开环聚合法在不同聚合条件下合成了系列的共聚产物PLGA，利用FT-IR、DSC、WAXD、~1H-NMR、凝胶渗透色谱仪(GPC)等对共聚产物的结构进行了表征。研究了聚合温度／时间、不同单体投料比对共聚物的相对分子质量、热性能以及结晶性能的影响，着重分析了单体投料比对共聚物热性能及结晶性能的影响。结果表明，在聚合条件为160℃／10h时，可以得到相对分子质量较高的PLGA无规共聚物，而在相同反应条件下，PLGA50／50的相对分子质量最大；同时，随着乙交酯投料比的增加，PLGA的熔点及玻璃化温度逐渐降低，结晶度降低至呈非晶态；但当乙交酯投料比高于70％后，PLGA又表现出结晶性，熔点和结晶度逐渐升高。可见，通过控制共聚条件，可以得到聚集态结构不同的PLGA，改变其热性能及结晶性，从而可以调节其降解速率，应用于生物工程的不同领域。更多还原

【Abstract】 In this thesis, high purified glycolide（GA） and L-lactide （L-LA） monomers were firstly synthesized through orthogonal experiments. Then PLGA copolymers were obtained by co-polymerization of the two monomers. The processing of the co-polymerization for controlling the microstructure and macro-performance of the materials were optimized, which established primary basis for practical use of PLGA.At first, orthogonal experiments were used to optimize the synthesis conditions for GA. Effects on the yield of the product, include the type and dosage of catalyst, reaction time, polymerization temperature were evaluated. The structure of GA were characterized by infrared spectroscopy （FTIR）, thermal analysis （DSC）, wide angle x-ray diffraction （WAXD） and nuclear magnetic resonant （¹H-NMR） techniques. The results indicated that relatively high yield can be obtained under the conditions of adding 0.8g Sn₂O₃, dewatering at 110～130℃/2h, polymerization at 180℃/4h and decomposition at 260～280℃. High purity GA can be prepared by re-crystallization for three times.Besides, by using lactic acid as monomer, L-lactide （L-LA） is synthesized by condensation polymerization and consequent de-polymerization steps. Effects of synthesis parameters on the yield were also investigated by orthogonal experiments, such as catalyst types and dosage, dewater temperature and decomposition temperature. The purification method on the yield and content of impurities （lactic acid and water） was studied. The molecular structure of prepared L-LA was characterized by FTIR, DSC and ¹H-NMR techniques in detail. Results indicated that the yield of L-LA can reach 80% when dewater and decomposition temperature are 130℃ and 190℃ respectively. After four times re-crystallization in ethyl acetate, high purity product can be obtained successfully.Finally, the open-ring polymerization method was used to synthesis a series of PLGA with various dosage ratios of GA and L-LA. The structure of the copolymers were analyzed by FTIR, DSC, WAXD, ¹H-NMR and gel permeation chromatogram （GPC）. The relationships of polymerization temperature/time, monomer ratios between relative更多还原