基于单电子转移活性自由基聚合技术的环境响应性光电功能聚合物的设计、合成与自组装行为
发布时间：2019-04-09 16:29
【摘要】：单电子转移活性自由基聚合(Single electron transfer-living radical polymerization,SET-LRP)是一种在原子转移活性自由基聚合(Atom transfer radical polymerization,ATRP)基础上发展而来的新的聚合方法。在SET-LRP聚合反应中,单质Cu(0)通过非均相外层电子转移使引发剂中结合较弱的碳-卤键在多相体系溶液中异裂产生自由基来激活休眠种,并形成自由基钝化-活化平衡来有效控制自由基的浓度,从而达到可控“活性自由基聚合”的目的。该聚合方法能够很好控制聚合物的相对分子质量、相对分子质量分布,并且还很容易改变聚合物的化学组分,设计合成具有复杂拓扑结构以及具有很高链端功能团含量功能高分子材料。本课题中我们主要以SET-LRP聚合技术并结合ATRP制备了一系列聚合物光电功能分子,并详细研究了不同环境因子对聚合物的聚合动力学、光电性能和自组装行为的影响。首先我们以成熟的室温下丙烯酸甲酯(Methyl acrylate,MA)在二甲基亚砜(Dimethyl sulfoxide,DMSO)中的SET-LRP聚合动力学作为研究对象。通过在反应中添加不同摩尔浓度的无水FeCl3,详细研究了其对MA的SET-LRP聚合动力学的影响。实验结果表明,加入Fe(III)以后,聚合反应仍然表现为活性自由基聚合,引发剂效率比较高,链端功能团被较为完美的保留,含量均在85%以上。此外,在加入一定量铁盐后所得聚合物的多分散性指数变大(1.19~1.14),但是和不加Fe(III)相比,影响不大。并且随着三价铁离子量Fe(III)含量的增加,其链增长速率常数下降,并且出现诱导期延长的现象,说明三价铁离子参与了SET-LRP的聚合动力学过程,它和在同样实验条件下二价铜所起的作用截然不同,显著变长。表明添加具有减活作用的无水FeCl3能够有效调节SET-LRP的聚合动力学。聚(N-异丙基丙烯酰胺)(Poly(N-isopropylacrylamide),PNIPAM)是一种两亲性环境敏感的高分子材料。该聚合物中含有亲水性酰胺基和疏水性异丙基,当外界温度发生变化时,通过分子间的相互作用其自身会发生可逆性的相变化。我们利用具有易于合成,可高效进行化学修饰、量子产率高等优点的四苯基乙烯(Tetraphenylethene,TPE)类分子作为引发剂。通过N-异丙基丙烯酰胺的SET-LRP聚合反应,制备了具有AIE(Aggregation-induced emission,AIE)效应的大分子引发剂PNIPAM-Br,然后以苯乙烯为单体,通过ATRP聚合制备两亲性嵌段聚合物PNIPAM-b-PSt,并详细研究了具有AIE效应的引发剂和两亲性嵌段聚合物在不同温度和浓度下光物理性质和自组装行为的变化情况。研究发现相同浓度条件下,随着温度的升高AIE效应引发剂荧光强度不断下降,而嵌段聚合物的荧光强度先上升。当温度超过到37 oC后,嵌段聚合物的荧光强度不断下降。同样的,通过依次改变AIE效应引发剂和嵌段聚合物在四氢呋喃和水混合溶剂中的浓度发现,随着浓度的减小,AIE效应引发剂的荧光强度不断下降,改变浓度时嵌段聚合物荧光强度的变化规律和改变温度时荧光强度的变化趋势相似,说明在双亲性嵌段聚合物末端挂接AIE效应的TPE分子是可以表征其聚集态结构的变化。最后我们又进一步研究了不同浓度混合溶剂中嵌段聚合物的自组装行为,随着分散液浓度的降低,组装体的尺寸变小,并经历从片状到球状再到无规则形状的演化过程,说明改变分散液的浓度可以大范围调节所得组装体的大小和形状。
[Abstract]:Single electron transfer-polymerization (SET-LRP) is a new method of polymerization developed on the basis of atom transfer active radical polymerization (ATRP). in that SET-LRP polymerization reaction, the simple substance Cu (0) generate free radicals in the multi-phase system solution by the heterogeneous outer layer electron transfer to generate free radicals in the multi-phase system solution to activate the dormant species, and form a free radical passivation-activation balance to effectively control the concentration of the free radicals, So as to achieve the purpose of controllable "active free radical polymerization". The polymerization method can well control the relative molecular mass and relative molecular weight distribution of the polymer, and also can easily change the chemical components of the polymer, and is designed and synthesized to have a complex topological structure and a high-chain end functional group content functional high molecular material. In this paper, a series of polymer photo-functional molecules were prepared by SET-LRP and ATRP, and the effects of different environmental factors on the polymerization kinetics, photoelectricity and self-assembly behavior of the polymer were studied in detail. The kinetics of SET-LRP polymerization of methyl acrylate (MA) in Dimethylacrylate (DMSO) at room temperature was first studied. The effect of its SET-LRP polymerization kinetics on MA was studied in detail by adding anhydrous FeCl3 with different molar concentrations in the reaction. The experimental results show that after the addition of Fe (III), the polymerization still shows that the polymerization of the active free radical, the initiator efficiency is high, the chain end functional group is preserved perfectly, and the content is above 85%. In addition, the polydispersity index of the polymer obtained after the addition of a certain amount of iron salt was increased (1.19 to 1.14), but the effect was not large compared with the addition of Fe (III). In addition, with the increase of the content of Fe (III) in the ferric ion, the rate of chain growth is decreased and the induction period is prolonged. It is indicated that the ferric ion is involved in the process of the polymerization of SET-LRP, which is very different from the action of the divalent copper under the same experimental conditions, and it becomes longer. It is shown that the addition of anhydrous FeCl3 with deactivation effect can effectively adjust the polymerization kinetics of SET-LRP. Poly (N-isopropylidenamine) (PNIPAM) is an amphiphilic environment-sensitive polymer material. The polymer contains a hydrophilic polar amine group and a hydrophobic isopropyl group, and when the external temperature is changed, the reversible phase change can occur through the interaction between the molecules. Tetraphenylethylene (TPE) molecules with the advantages of easy synthesis, high efficiency for chemical modification, high quantum yield and the like can be used as the initiator. A macromolecular initiator PNIPAM-Br with AIE (AIE) effect was prepared by using a SET-LRP polymerization of N-isopropylamide and then the amphipathic block polymer PNIPAM-b-PSt was prepared by ATRP polymerization using styrene as a monomer. The changes of light physical properties and self-assembly behavior of initiator and amphipathic block polymer with AIE effect at different temperatures and concentrations were studied in detail. The fluorescence intensity of the block polymer was first increased with the increase of the temperature and the increase of the fluorescence intensity of the AIE effect. When the temperature exceeds 37 oC, the fluorescence intensity of the block polymer decreases. In the same way, by sequentially changing the concentration of the AIE effect initiator and the block polymer in the tetrahydrogen peroxide and the water mixed solvent, as the concentration is reduced, the fluorescence intensity of the AIE effect initiator is continuously reduced, The change of the fluorescence intensity of the block polymer when the concentration is changed and the change tendency of the fluorescence intensity at the time of the change are similar, and the change of the structure of the aggregation state can be characterized by the AIE effect on the end of the amphiphilic block polymer. In that end, we further study the self-assembly behavior of the block polymer in the mixed solvent of different concentration, with the decrease of the concentration of the dispersion liquid, the size of the assembly becomes small, and the evolution process from the sheet-like to the non-regular shape is experience. The size and shape of the resulting assembly can be adjusted in a large range by changing the concentration of the dispersion.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.5
本文编号：2455336
[Abstract]:Single electron transfer-polymerization (SET-LRP) is a new method of polymerization developed on the basis of atom transfer active radical polymerization (ATRP). in that SET-LRP polymerization reaction, the simple substance Cu (0) generate free radicals in the multi-phase system solution by the heterogeneous outer layer electron transfer to generate free radicals in the multi-phase system solution to activate the dormant species, and form a free radical passivation-activation balance to effectively control the concentration of the free radicals, So as to achieve the purpose of controllable "active free radical polymerization". The polymerization method can well control the relative molecular mass and relative molecular weight distribution of the polymer, and also can easily change the chemical components of the polymer, and is designed and synthesized to have a complex topological structure and a high-chain end functional group content functional high molecular material. In this paper, a series of polymer photo-functional molecules were prepared by SET-LRP and ATRP, and the effects of different environmental factors on the polymerization kinetics, photoelectricity and self-assembly behavior of the polymer were studied in detail. The kinetics of SET-LRP polymerization of methyl acrylate (MA) in Dimethylacrylate (DMSO) at room temperature was first studied. The effect of its SET-LRP polymerization kinetics on MA was studied in detail by adding anhydrous FeCl3 with different molar concentrations in the reaction. The experimental results show that after the addition of Fe (III), the polymerization still shows that the polymerization of the active free radical, the initiator efficiency is high, the chain end functional group is preserved perfectly, and the content is above 85%. In addition, the polydispersity index of the polymer obtained after the addition of a certain amount of iron salt was increased (1.19 to 1.14), but the effect was not large compared with the addition of Fe (III). In addition, with the increase of the content of Fe (III) in the ferric ion, the rate of chain growth is decreased and the induction period is prolonged. It is indicated that the ferric ion is involved in the process of the polymerization of SET-LRP, which is very different from the action of the divalent copper under the same experimental conditions, and it becomes longer. It is shown that the addition of anhydrous FeCl3 with deactivation effect can effectively adjust the polymerization kinetics of SET-LRP. Poly (N-isopropylidenamine) (PNIPAM) is an amphiphilic environment-sensitive polymer material. The polymer contains a hydrophilic polar amine group and a hydrophobic isopropyl group, and when the external temperature is changed, the reversible phase change can occur through the interaction between the molecules. Tetraphenylethylene (TPE) molecules with the advantages of easy synthesis, high efficiency for chemical modification, high quantum yield and the like can be used as the initiator. A macromolecular initiator PNIPAM-Br with AIE (AIE) effect was prepared by using a SET-LRP polymerization of N-isopropylamide and then the amphipathic block polymer PNIPAM-b-PSt was prepared by ATRP polymerization using styrene as a monomer. The changes of light physical properties and self-assembly behavior of initiator and amphipathic block polymer with AIE effect at different temperatures and concentrations were studied in detail. The fluorescence intensity of the block polymer was first increased with the increase of the temperature and the increase of the fluorescence intensity of the AIE effect. When the temperature exceeds 37 oC, the fluorescence intensity of the block polymer decreases. In the same way, by sequentially changing the concentration of the AIE effect initiator and the block polymer in the tetrahydrogen peroxide and the water mixed solvent, as the concentration is reduced, the fluorescence intensity of the AIE effect initiator is continuously reduced, The change of the fluorescence intensity of the block polymer when the concentration is changed and the change tendency of the fluorescence intensity at the time of the change are similar, and the change of the structure of the aggregation state can be characterized by the AIE effect on the end of the amphiphilic block polymer. In that end, we further study the self-assembly behavior of the block polymer in the mixed solvent of different concentration, with the decrease of the concentration of the dispersion liquid, the size of the assembly becomes small, and the evolution process from the sheet-like to the non-regular shape is experience. The size and shape of the resulting assembly can be adjusted in a large range by changing the concentration of the dispersion.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.5
【参考文献】
相关期刊论文 前1条
1 袁伟;袁媛;陈于蓝;;机械力诱导发光高分子材料[J];高分子学报;2016年11期
，本文编号：2455336
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