RAFT分散聚合制备热敏性的纳米颗粒
发布时间：2018-08-24 15:59
【摘要】：近年来,可逆加成断裂链转移(RAFT)聚合在合成结构明确、分子量可控的高分子方面取得了重大的进展,引起了人们极大的兴趣。本论文,通过RAFT聚合制备了两种热敏性纳米颗粒。首先,利用聚N-异丙基丙烯酰胺(PNIPAM)在混合溶剂中的非共溶剂效应,即PNIPAM在两种良溶剂的混合溶剂中,溶解性反而变差的现象。选择乙醇和水混合液作为溶剂,利用RAFT分散聚合的方法合成了多种组分、结构和功能的热敏性纳米凝胶。其次,利用RAFT分散聚合先合成臂的方法,选用亲水性的聚N,N-二甲基丙烯酰胺(PDMA)和热敏性的PNIPAM作为高分子臂,水作为溶剂,合成出热敏性的杂臂星形高分子,并研究了其作为乳化剂的应用。主要研究内容如下:1.选择75:25(v/v)的水-乙醇溶剂作为反应溶剂,PDMA作为大分子链转移剂,RAFT分散聚合NIPAM,成功制备出热敏性的纳米凝胶。用凝胶渗透色谱(GPC)和核磁(NMR)氢谱进行表征,发现RAFT控制良好,聚合动力学曲线呈线性关系。系统地研究了大分子链转移剂PDMA的分子量、固体含量、交联剂用量对合成纳米凝胶的影响。结果显示,高PNIPAM聚合度、高固体含量、高交联剂浓度时,更容易形成稳定的纳米凝胶。将亲水性单体N-(2-羟乙基)丙烯酰胺(HEAM),双丙酮丙烯酰胺(DAAM)及疏水性单体丙烯酸正丁酯(BA),荧光素-O-丙烯酸酯(FLA),1,6-己二醇二丙烯酸酯(HDDA)分别与NIPAM共聚,利用RAFT分散聚合成功制备出多组分、功能化的纳米凝胶。另外,两亲性嵌段共聚物PDMA-b-PBA用作大分子链转移剂,成功制备出三嵌段的纳米凝胶。纳米凝胶的热敏性通过动态光散射(DLS)进行表征。2.我们选用亲水性的PDMA和热敏性的PNIPAM作为高分子臂,1,6-己二醇二丙烯酸酯(HDDA)作为交联剂,抗坏血酸(ASA)和叔丁基过氧化氢(t-Bu OH)作为引发剂,水为反应溶剂,成功地制备出热敏性的杂臂星形高分子。通过控制两种链的投料比例来调节星形高分子中两种高分子臂的比例,从而改变星形高分子的低临界溶解温度(LCST),发现制备的杂臂星形高分子确实具有明显的热敏性,而且改变PNIPAM比例,星形高分子的LCST会发生变化。用各种不同LCST的星形高分子作为乳化剂,制备了一系列乳液,使用共聚焦显微镜观察形成乳液的形貌,证明了杂臂星形高分子有很好的乳化能力。
[Abstract]:In recent years, reversible addition chain transfer (RAFT) polymerization has made great progress in the synthesis of polymers with clear structure and controllable molecular weight, which has aroused great interest. In this thesis, two kinds of thermosensitive nanoparticles were prepared by RAFT polymerization. Firstly, the non-co-solvent effect of poly (N-isopropylacrylamide) (PNIPAM) in mixed solvents is used, that is, the solubility of PNIPAM in two good solvents becomes worse. Thermosensitive nanogels with various components, structures and functions were synthesized by RAFT dispersion polymerization with ethanol and water mixture as solvents. Secondly, the thermosensitive hetero-arm star polymer was synthesized by the method of RAFT dispersion polymerization, the hydrophilic poly (N- N- dimethylacrylamide) (PDMA) and the thermosensitive PNIPAM were used as the polymer arm and the water as the solvent to synthesize the thermosensitive hetero-arm star polymer. Its application as emulsifier was also studied. The main research contents are as follows: 1. The thermosensitive nanogels were successfully prepared by using the water-ethanol solvent of 75:25 (v / v) as the reaction solvent and NIPAM, as the macromolecular chain transfer agent. Gel permeation chromatography (GPC) and nuclear magnetic field (NMR) hydrogen spectra were used to characterize the results. It was found that RAFT was well controlled and the polymerization kinetics curve was linear. The effects of molecular weight, solid content and crosslinking agent amount of macromolecular chain transfer agent (PDMA) on the synthesis of nanogels were systematically studied. The results showed that stable nanogels were more easily formed with high PNIPAM polymerization degree, high solid content and high crosslinking agent concentration. The hydrophilic monomer N- (2-hydroxyethyl) acrylamide (HEAM), diacetone acrylamide (DAAM) and hydrophobic monomer n-butyl acrylate (BA), fluorescein (HDDA) were copolymerized with NIPAM, respectively. Multicomponent and functionalized nanogels were successfully prepared by RAFT dispersion polymerization. In addition, amphiphilic block copolymer PDMA-b-PBA was used as macromolecular chain transfer agent to successfully prepare triblock nanogels. The thermal sensitivity of nanogels was characterized by dynamic light scattering (DLS). Hydrophilic PDMA and thermosensitive PNIPAM were used as crosslinking agent, ascorbic acid (ASA) and tert-Ding Ji hydrogen peroxide (t-Bu OH) as initiator and water as solvent. The thermosensitive hetero-arm star polymer was successfully prepared. By controlling the feeding ratio of two chains to adjust the ratio of two kinds of polymer arms, it is found that the hetero-arm star polymer has obvious thermal sensitivity by changing the low critical dissolution temperature (LCST),) of the star polymer. And changing the ratio of PNIPAM, star polymer LCST will change. A series of emulsions were prepared by using different LCST starlike polymers as emulsifiers. The morphology of the emulsion was observed by confocal microscope.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
本文编号：2201312
[Abstract]:In recent years, reversible addition chain transfer (RAFT) polymerization has made great progress in the synthesis of polymers with clear structure and controllable molecular weight, which has aroused great interest. In this thesis, two kinds of thermosensitive nanoparticles were prepared by RAFT polymerization. Firstly, the non-co-solvent effect of poly (N-isopropylacrylamide) (PNIPAM) in mixed solvents is used, that is, the solubility of PNIPAM in two good solvents becomes worse. Thermosensitive nanogels with various components, structures and functions were synthesized by RAFT dispersion polymerization with ethanol and water mixture as solvents. Secondly, the thermosensitive hetero-arm star polymer was synthesized by the method of RAFT dispersion polymerization, the hydrophilic poly (N- N- dimethylacrylamide) (PDMA) and the thermosensitive PNIPAM were used as the polymer arm and the water as the solvent to synthesize the thermosensitive hetero-arm star polymer. Its application as emulsifier was also studied. The main research contents are as follows: 1. The thermosensitive nanogels were successfully prepared by using the water-ethanol solvent of 75:25 (v / v) as the reaction solvent and NIPAM, as the macromolecular chain transfer agent. Gel permeation chromatography (GPC) and nuclear magnetic field (NMR) hydrogen spectra were used to characterize the results. It was found that RAFT was well controlled and the polymerization kinetics curve was linear. The effects of molecular weight, solid content and crosslinking agent amount of macromolecular chain transfer agent (PDMA) on the synthesis of nanogels were systematically studied. The results showed that stable nanogels were more easily formed with high PNIPAM polymerization degree, high solid content and high crosslinking agent concentration. The hydrophilic monomer N- (2-hydroxyethyl) acrylamide (HEAM), diacetone acrylamide (DAAM) and hydrophobic monomer n-butyl acrylate (BA), fluorescein (HDDA) were copolymerized with NIPAM, respectively. Multicomponent and functionalized nanogels were successfully prepared by RAFT dispersion polymerization. In addition, amphiphilic block copolymer PDMA-b-PBA was used as macromolecular chain transfer agent to successfully prepare triblock nanogels. The thermal sensitivity of nanogels was characterized by dynamic light scattering (DLS). Hydrophilic PDMA and thermosensitive PNIPAM were used as crosslinking agent, ascorbic acid (ASA) and tert-Ding Ji hydrogen peroxide (t-Bu OH) as initiator and water as solvent. The thermosensitive hetero-arm star polymer was successfully prepared. By controlling the feeding ratio of two chains to adjust the ratio of two kinds of polymer arms, it is found that the hetero-arm star polymer has obvious thermal sensitivity by changing the low critical dissolution temperature (LCST),) of the star polymer. And changing the ratio of PNIPAM, star polymer LCST will change. A series of emulsions were prepared by using different LCST starlike polymers as emulsifiers. The morphology of the emulsion was observed by confocal microscope.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1
【参考文献】
相关期刊论文 前1条
1 顾婷;查刘生;;相转变温度范围窄的聚(N-异丙基丙烯酰胺)温敏性微凝胶[J];功能高分子学报;2007年03期
，本文编号：2201312
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