两亲性接枝嵌段共聚物分子刷的合成及自组装行为

发布时间：2018-03-28 12:31

本文选题：分子刷　切入点：自组装　出处：《华东师范大学》2017年硕士论文

【摘要】：聚合物分子刷因其独特的分子结构(如分子量大可单分子操作、主链呈现刚性等)在纳米科学、生物医学等领域存在广泛的应用前景,目前已成为高分子科学研究的热点之一。另一方面,聚肽不仅具有良好的生物相容性和生物降解性,而且由于分子内或分子外氢键作用能形成丰富的二级结构(如α螺旋、β折叠等),能够组装形成新颖独特的组装结构体(如囊泡、纤维、圆盘状和超螺旋结构等),并能广泛应用于生物载药、生物矿化和基因工程等领域。联合聚合物分子刷和聚肽的优点,将它们构筑到同一体系中而形成聚肽分子刷,有助于拓展聚合物分子刷的研究及其应用领域范围,并能满足某些特殊应用领域的需求。同时,也可以选择性对聚肽分子刷进行功能化修饰,将功能化基团引入得到功能化的聚肽分子刷,拓展其应用范围。本文联合RAFT聚合法和开环聚合法,合成了聚肽分子刷,详细地表征其结构。较为系统地研究了其自组装行为,探讨了其组装机理。同时,也对其金纳米粒子负载进行了初步的探讨,主要工作内容包含两个部分:第一部分工作内容:首先,利用RAFT聚合办法制备了不同聚合度聚甲基丙烯酸缩水甘油酯(PGMA),开环后得到侧基为羟基的聚合物PGMA-OH,引发丙交酯单体(D,L-lactide)聚合,从而得到了侧链为聚丙交酯(PLA)聚合物分子刷PGMA-g-PLA。其次,通过侧链端基改性法将N-α-芴甲氧羰基-N-ε-叔丁氧羰基-L-赖氨酸[Fmoc-Lys(Boc)-OH]引入端基,并脱去保护基团叔丁氧羰基(Boc),从而得到侧端为氨基(-NH2)的聚合物分子刷。最后,采用α-氨基酸-N-羧基内酸酐(NCA)法,引发单体NCA-Lys(Cbz)和NCA-Lys(Fmoc)开环聚合得到聚肽分子刷PGMA-g-(PLA-b-PLys(Cbz/Fmoc)),联合NMR、IR和GPC等技术详细地表征了它们的化学结构。采用溶液自组装法,较为详细地研究了该聚肽分子刷的自组装行为,考察了外界影响因素(溶剂、浓度、含水量等)对自组装体形貌的影响,获得了包含叶片状、多孔胶束等组装体结构。为了进一步拓展其应用,我们通过原位法将该聚合物负载到金纳米粒子表面,得到聚肽分子刷/金纳米粒子杂化材料,并初步探讨了其在不同溶剂中聚集体形貌变化规律,为该类材料的实际应用提供了参考。第二部分工作内容:采用上述类似的合成路线,首先合成出侧链为聚丙交酯(PLA)聚合物分子刷PGMA-g-PLA。其次,通过酯化反应,将三硫代碳酸酯修饰到聚合物分子刷PGMA-g-PLA的侧链端基上,从而得到大分子链转移剂PGMA-g-PLA-CTPA。最后,通过RAFT聚合法,以偶氮二异丁基氰(AIBN)为引发剂引发单体聚乙二醇单甲醚甲基丙烯酸酯(EGMA)(Mn=293 g/mol)聚合,合成出了以聚甲基丙烯酸缩水甘油酯(PGMA)为主链,以聚丙交酯和聚(聚乙二醇单甲醚甲基丙烯酸酯)为侧链嵌段共聚物的聚合物分子刷PGMA-g-(PLA-b-PEGMA),详细表征其化学结构。由于聚(聚乙二醇单甲醚甲基丙烯酸酯)具有温敏性,我们较为详细地探讨了不同温度(10℃、20℃和30℃)条件下对其自组装体形貌结构的影响,获得了包含纳米棒、纳米纤维及多孔囊泡等多种组装体结构。
[Abstract]:Polymer brushes because of its unique molecular structure (such as high molecular weight single molecular chain operation, showing rigidity etc.) in nano science, has wide application prospect biomedical and other fields, has become a hot research topic in polymer science. On the other hand, poly peptide not only has good biocompatibility and biodegradability. Biological, and because intramolecular or molecular hydrogen bonding can be formed of two rich structures (such as alpha helices, beta sheet, etc.) can be assembled to form the assembly structure of the novel and unique (such as vesicle, fiber, disc and super spiral structure), and can be widely used in biological drug, biological mineralization and gene engineering. Combined with polymer brushes and poly peptide advantages, build them into the same system and the formation of poly peptide molecular brush, helps to expand the research and application of polymer molecular brush field range, and can meet the needs of some The special needs of applications. At the same time, can also be a selective functionalization of poly peptide molecular brushes, functional groups are introduced by poly peptide molecular brush function, expand the scope of its application. This paper combined with RAFT polymerization and ring opening polymerization, poly peptide molecular brush synthesized and characterized in detail. Systematically studied the self-assembly behavior, discusses the mechanism of the assembly. At the same time, the gold nanoparticles were discussed. The main contents include two parts: the first part of the work as follows: firstly, polymerization prepared with different degree of polymerization of poly glycidyl methacrylate by RAFT (PGMA), open loop is obtained after the side group polymer PGMA-OH hydroxyl, initiated lactide monomers (D, L-lactide) and side chain polymerization, polylactide (PLA) polymer brush PGMA-g-PLA. second, through the side chain modification method The N- alpha 9-fluorenylmethoxycarbonyl -N- epsilon t-Boc -L- lysine [Fmoc-Lys (Boc) -OH] into the terminal, and take off protective groups t-butyloxycarbonyl (Boc), in order to get the side end amino (-NH2) of the polymer brushes. Finally, using the alpha amino acid carboxyl -N- anhydride (NCA) method of Inimer NCA-Lys (Cbz) and NCA-Lys (Fmoc) ring opening polymerization of poly peptide molecular brush PGMA-g- (PLA-b-PLys (Cbz/Fmoc)), combined with NMR, IR and GPC technology in detail to characterize their chemical structures. By solution self-assembly method, a more detailed study of the self-assembly behavior of the poly peptide molecular brush, effects of external factors (solvent, concentration, moisture etc.) influence on the self-assembly morphology, obtained contains leaf shaped porous micelles assembly structure. In order to further expand its application, we will through the in situ method of the polymer supported gold nanoparticles surface, get peptide points The brush / gold nanoparticles hybrid material, and discusses its aggregates in different solvents morphology changes, which provides a reference for the practical application of this kind of materials. Part second: the synthetic route is similar to the above, the first synthesis of side chain of poly (PLA) polymer brush PGMA-g-PLA. followed by esterification three, thiocarbonate modified end group in side chain polymer brushes on the PGMA-g-PLA, so as to obtain the macromolecular chain transfer agent PGMA-g-PLA-CTPA. finally, via RAFT polymerization, with two azo isobutyl cyanide (AIBN) as the initiator monomer of polyethylene glycol methyl ether methacrylate (EGMA) (Mn=293 g/mol) was synthesized by polymerization. Poly glycidyl methacrylate (PGMA) as the main chain, with poly lactide and poly (ethylene glycol methyl ether methacrylate) polymer brush PG copolymers as side chain MA-g- (PLA-b-PEGMA), characterized by their chemical structure. The poly (polyethylene glycol methacrylate) is temperature sensitive, we discussed in more detail at different temperatures (10 C, 20 C and 30 C) on the condition of the self assembling effect of shape structure, obtained contains nanorods, nanofibers and porous vesicles and other assembly structure.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631

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