巯基功能化聚酯的合成

巯基功能化聚酯的合成(论文10000字)
摘要
在过去的几年里，脂肪族聚酯因为通过金属催化剂来开环聚合，在合成的过程中产生一定的金属残留物，使得人们不得不限制它在医学上的应用。本文采用的是稀土催化剂来催化开环聚合制备得到脂肪族聚酯，使用稀土催化剂催化单体得到的产物具有无金属残留、反应过程温和可控等优点，因此，它在生物医疗领域应用更为广阔。
稀土催化剂相较于其他金属化合物，稀土化合物的毒性较小，在制备过程中不会出现金属残留，导致合成的聚合物降解以及制备的聚合物材料颜色太深等问题。基于以上优点，本文选用三(2,6-二叔丁基-4甲基苯氧基)镧为催化剂，考量它在实验过程中对己内脂开环聚合的研究。
在此种方法下，可以避免巯基保护、脱保护的繁杂步骤和金属催化剂导致的金属残留问题。在反应温度为30摄氏度，ε-己内酯/巯基己醇投料比为40:1，甲苯为溶液的条件下反应适当时间，ε-己内酯的转化率达到99 %，巯基选择性为76 %。所得到的产物巯基功能化聚己内酯聚的结构表征可通过核磁共振氢谱、体积排阻色谱SEC分析，可以检测产物的分子结构清晰，分子量分布PDI小于1.3。

关键词：巯基  开环聚合  己内脂  稀土催化剂
Abstract
Over the past few years, aliphatic polyesters were catalyzed via organometallic compounds catalyzed ring-opening polymerization, resulting in metal residue which would restrict the use of medical field. In this paper, the rare earth catalyst is used to catalyze the ring-opening polymerization to obtain aliphatic polyester. The product obtained by using the rare earth catalyst to catalyze the monomer has the advantage of no metal residue and the reaction process is gentle and controllable, so it broadens the field of the biomedical application.
Compared to other metal compounds, less toxic rare earth compounds would not cause metal residue in the preparation process, in the absence of the problems of degradation of polymers and dark colors of product., Based on the above advantages, this paper chooses tris (2,6-di-tert-butyl-4-methylphenoxy) lanthanum as catalyst, and studies its ring-opening polymerization of caprolactone. In this way, it is possible to avoid the complicated protection and deprotection steps of thiol and the metal residue problem caused by the metal catalyst. The conversion of ε-caprolactone was 99% and the thiol fidelity was 76% at the reaction temperature of 30 ° C, feed ration of ε-caprolactone / mercaptohexanol was 40: 1 and solvent was toluene The structural characterization of the obtained product poly (ε - caprolactone) can be detected by nuclear magnetic resonancespectroscopy and size exclusion chromatography. The molecular structure of the product is clear and molecular weight distribution is less than 1.3.
Keywords: mercapto ；Ring-opening Polymerization ；ε-caprolactone ；Rare earth catalyst

目录
摘要    I
ABSTRACT    II
第一章文献综述    1
1.1生物降解高分子材料    1
1.1.1生物降解高分子材料的分类    1
1.1.2生物降解高分子的降解性    2
1.1.3生物降解高分子的应用    2
1.2聚酯材料    2
1.2.1聚酯均聚物    2
1.2.2嵌段共聚物    3
1.2.3双亲嵌段共聚物    3
1.3巯基功能化聚酯材料    3
1.3.1 巯基功能化聚酯的合成    4
1.4开环聚合催化体系    4
1.4.1酶催化体系    4
1.4.2有机催化法    5
1.4.3金属催化剂体系    5
1.5本课题研究目的和意义    6
第二章巯基功能化聚酯的合成    7
2.1实验部分    7
2.1.1实验试剂    7
2.1.2实验方法    9
2.1.3表征方法    11
2.2结果与讨论    11
2.2.1催化剂滴定数据    11
2.2.2NMR分析    12
2.2.3 GPC分析    13
2.2.4反应时间与转化率    13
2.2.5巯基含量    14
2.3本章小结    15
第三章结论与展望    17
3.1 结论    17
3.2 展望    17
参考文献    18
致谢    20