基于PGMA嵌段共聚物的微纳米粒子的制备

发布时间：2018-05-04 14:34

本文选题：嵌段共聚物 + RAFT分散聚合　；参考：《深圳大学》2017年硕士论文

【摘要】：聚合物微纳米粒子因其高比表面积、低密度和较强吸附能力等优点,在吸附分离、催化剂负载、离子交换、传感器、生物医药等诸多领域具有广泛的应用。甲基丙烯酸缩水甘油酯(GMA)作为一种功能性单体,其携带的环氧基团,可以进行多种化学反应,其聚合物常被用作功能性材料。本文利用可逆加成断裂链转移(RAFT)溶液聚合制备了PGMA基嵌段共聚物,结合再乳化制备了多孔微球;利用RAFT分散聚合诱导自组装(PISA)制备了PGMA基嵌段共聚物多重形貌胶束。利用RAFT溶液聚合制备了三种不同嵌段比的聚甲基丙烯酸羟丙酯-b-聚甲基丙烯酸缩水甘油酯(PHPMA-b-PGMA)。将PHPMA-b-PGMA的二氯甲烷(DCM)溶液加入含乳化剂的水溶液中,通过磁力搅拌(M)、高速乳化(H)和膜乳化(SPG)等乳化手段形成水包油(O/W)乳液体系,通过挥发溶剂制备多孔微球。研究发现,高速乳化和磁力搅拌联用所制得的微球形状规整,表面孔数目较多。十二烷基硫酸钠(SDS)作为乳化剂被用于制备多孔微球,在SDS浓度为1 CMC时,能制得粒径规整的多孔微球。在一定浓度范围内,随着SDS浓度增大,微球表面的孔越多,粒径越小;十六烷基三甲基溴化铵(CTAB)能制得规整且粒径较均匀的微球,但是无孔;聚氧乙烯辛基苯酚醚-10(OP-10)即使在浓度达到100 CMC时,仍不能稳定乳液体系。以聚甲基丙烯酸聚乙二醇单甲醚酯(POEGMA)为大分子链转移剂,在乙醇中调控GMA的RAFT分散聚合,通过PISA得到了POEGMA-b-PGMA多种形貌的自组装聚集体。研究发现体系具有较好的聚集体形貌和分子量双重可调控性,通过调节目标聚合度和控制转化率能自组装成球形胶束(50 nm)、纳米线(50 nm)和囊泡(100-300 nm)。随聚合反应的进行,聚合物的分子量随转化率呈线性增长且分子量分布窄,显示出良好的活性聚合特征。三乙胺催化环氧交联后的聚集体具有良好的溶剂耐受性,说明本实验所制备的POEGMA-b-PGMA纳米粒子具有优良的可交联和再修饰特性。在第二嵌段加入一定摩尔比的甲基丙烯酸叔丁酯(TBMA),通过PISA制备了POEGMA-b-P(GMA-co-TBMA)自组装聚集体,与纯GMA体系相比,形貌发生了较大变化。以两种大分子链转移剂POEGMA和POEGMA-b-PGMA复合调控苯乙烯(St)在乙醇中的RAFT分散聚合,制备了AC/ABC两嵌段-三嵌段共混的多重形貌自组装聚集体。随着St的目标聚合度的提高,依次得到纳米线和囊泡混合形貌、囊泡和微球。通过化学修饰和纳米金负载实验表明,两嵌段和三嵌段共聚物在不同的聚集体上并不呈均匀分布,在单一囊泡形貌中形成多组分囊泡壁结构。
[Abstract]:Polymer nanoparticles have been widely used in many fields, such as adsorption separation, catalyst loading, ion exchange, sensor, biomedicine and so on, because of their high specific surface area, low density and strong adsorption ability. As a functional monomer, glycidyl methacrylate (GMA) carries epoxy groups which can undergo a variety of chemical reactions. Its polymers are often used as functional materials. In this paper, PGMA block copolymers and porous microspheres were prepared by reversible addition chain transfer (Raft) solution polymerization, and PGMA block copolymers were prepared by RAFT dispersion polymerization induced self-assembly. Three different block ratios of poly (hydroxypropyl methacrylate) -b- glycidyl methacrylate (PHPMA-b-PGMAA) were prepared by RAFT solution polymerization. The PHPMA-b-PGMA solution was added to the aqueous solution containing emulsifier. The oil-in-water / o / w emulsion system was formed by magnetic stirring, high speed emulsification and membrane emulsification. The porous microspheres were prepared by volatile solvent. It is found that the microspheres prepared by the combination of high speed emulsification and magnetic stirring have a regular shape and a large number of surface pores. Sodium dodecyl sulfate was used as emulsifier to prepare porous microspheres. When the concentration of SDS was 1 CMC, the porous microspheres with regular particle size could be prepared. In a certain concentration range, with the increase of SDS concentration, the more pores on the surface of the microspheres, the smaller the particle size, the more regular and homogeneous microspheres can be prepared by cetyltrimethylammonium bromide, but without pores. Poly (oxyethylene octyl phenol ether-10 OP-10) could not stabilize the emulsion system even when the concentration was up to 100 CMC. Poly (ethylene glycol monomethyl methacrylate) was used as macromolecular chain transfer agent to control the RAFT dispersion polymerization of GMA in ethanol. The self-assembled aggregates with various morphologies of POEGMA-b-PGMA were obtained by PISA. It has been found that the system has the dual controllability of aggregate morphology and molecular weight. By adjusting the degree of polymerization and controlling the conversion rate, the system can self-assemble into spherical micelle (50 nm), nanowire (50 nm) and vesicle (100-300 nm). With the polymerization, the molecular weight of the polymer linearly increases with the conversion and the molecular weight distribution is narrow, showing good characteristics of active polymerization. Triethylamine catalyzed epoxy crosslinked aggregates have good solvent tolerance, which indicates that the POEGMA-b-PGMA nanoparticles prepared in this experiment have excellent crosslinking and remodification properties. The POEGMA-b-PnGMA-co-TBMA-self-assembled aggregates were prepared by adding a certain molar ratio of tert-butyl methacrylate to the second block. Compared with the pure GMA system, the morphology of POEGMA-b-PnGMA-co-TBMA-self-assembled aggregates was changed greatly. The RAFT dispersion polymerization of styrene stave in ethanol was controlled by two macromolecular chain transfer agents POEGMA and POEGMA-b-PGMA. The multifold morphology self-assembly aggregates of AC/ABC diblock to triblock blend were prepared. With the increase of the degree of polymerization of St, the mixed morphology of nanowires and vesicles, vesicles and microspheres were obtained in turn. The chemical modification and nano-gold loading experiments showed that the diblock and triblock copolymers were not uniformly distributed in different aggregates and formed a multicomponent vesicle wall structure in a single vesicle morphology.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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