【作者】 刘翠华；

【导师】 颜德岳； 高超；

【作者基本信息】 上海交通大学 ， 材料学， 2007， 博士

【摘要】 超支化聚合物是一类具有三维立体构造的高度支化的大分子。经过近15年的探索与发展,该领域在合成、功能化改性及应用研究等方面已取得了许多突破性成果,为超支化聚合物的开发应用打下了良好的基础。尽管如此,该领域还有许多问题亟待进一步探索。本论文在综述前人工作的基础上,针对该领域存在的一些问题进行深入研究,并发现了一些有趣的新现象。运用本课题组提出的“不等活性双组分单体对”策略,成功地合成了水溶性超支化聚酰胺胺;详细研究了超支化聚酰胺胺及其它水溶性超支化聚合物的超分子封装与超分子自组装行为,尤其是发现了超支化聚合物的协同封装现象,并利用溶剂挥发诱导自组装方法,在硅、石英、云母等固体表面上得到了规则排列的多孔膜,还将装载了染料分子的超支化聚合物进行自组装,得到了荧光多孔膜。具体研究方法和结果如下。1超支化聚酰胺胺的合成、改性及表征选用商品化且价格便宜的AB型单体丙烯酸甲酯和乙二胺(EDA)、二乙基三胺(DETA)、三乙基四胺(TETA)、四乙基五胺(TEPA)、五乙基六胺(PEHA)等Cn型单体作为原料,通过不等活性单体对法(CMM)合成了一系列具有广泛应用前景的水溶性脂肪族超支化聚酰胺胺。对反应时间、温度、压力等参数进行了条件试验,总结了通过不等活性单体对法合成超支化聚酰胺胺的切实可行的反应条件。超支化聚酰胺胺的末端基团和性质可以通过改变AB和Cn型单体的比例来调整。用FTIR、NMR、DSC、TGA等对超支化聚酰胺胺进行表征,发现随着AB和Cn的投料比的改变,聚合物的溶解性、热性能、封装性能等均发生变化。核磁结果表明,当丙烯酸甲酯和多元胺的投料比较低时,聚酰胺胺末端基团为胺基;当该投料比较高时,聚合物末端基团为甲氧基;投料比越大,产物末端的甲氧基越多,残留的胺基越少。所得的超支化聚酰胺胺在氯仿和极性溶剂(如DMF、DMAc、DMSO、水、甲醇、乙醇等)中溶解性很好,而在一些非极性溶剂和弱极性溶剂(如丙酮、THF和乙醚等)中溶解性较差;且随着投料比的提高,产物在非极性溶剂中的溶解性逐渐变好。用不同的Cn单体合成的聚合物在非极性溶剂中的溶解性也不同,用EDA作为Cn单体得到的产物在丙酮、THF和乙醚中的溶解性明显比用烷基链数目较多的TEPA和PEHA作为Cn单体得到的产物的溶解性差。随着投料比的提高,产物玻璃化转变温度呈现先增大后减小的趋势。末端基团为胺基的产物不能封装染料小分子,而末端基团为甲氧基的产物可以封装少量染料分子。采用苯甲酰氯和棕榈酰氯对末端为胺基的超支化聚酰胺胺进行改性,得到具有核壳型两亲性结构的超支化聚酰胺胺。酰氯对胺基进行改性后,聚合物的溶解性、热性能、荧光性能及超分子封装性能均发生了变化。所有经过酰化改性得到的产物均不溶于水。苯甲酰氯改性的产物在丙酮和THF等非极性溶剂中的溶解性比改性前好。棕榈酰氯改性的产物不能在DMF、DMAC、DMSO、甲醇等极性溶剂中溶解,但仍然可以溶解在氯仿和THF中,在乙醚中也能部分溶解。改性前的产物相比,苯甲酰氯封端产物的玻璃化转变温度明显提高。棕榈酰氯改性的产物由于长链烷基的引入会发生结晶。改性前,所有产物失重5%的温度均在200℃以下,改性后产物的热性能提高,300℃时失重仍不到5%。所得的超支化聚酰胺胺具有荧光性能,酰氯封端会改变超支化聚酰胺的荧光性质,且超支化聚酰胺胺的发射峰位置受激发光波长及溶液浓度影响。改性后,超支化聚酰胺胺对染料的封装性能也明显提高。特殊的结构与性能使这类超支化聚酰胺胺在药物传输、污水处理、反应催化、涂料、表面活性剂、自组装等诸多领域中有着广阔的应用前景。2两亲性超支化聚酰胺对染料的超分子封装行为研究采用两亲性核壳型超支化聚酰胺胺为主体,研究了这类聚合物对染料分子的超分子封装行为。重点考察了采用丙烯酸甲酯和二乙基三胺(投料比为1.2 : 1)制得的超支化聚酰胺胺HP(DETA-MA)1.2的棕榈酰氯改性后的产物HP(DETA-MA)1.2P对染料的超分子封装行为,测定了HP(DETA-MA)1.2P对刚果红(CR)、甲基橙(MO)、甲基蓝(MB)、荧光素钠(FSS)、酸性曙红(EY)、荧光桃红(PB)、虎红(RB)等染料的装载量(Cload),发现HP(DETA-MA)1.2P对不同染料的装载能力不同,平均每个HP(DETA-MA)1.2P分子能够装载约22.4个刚果红分子,而仅能装载0.63个甲基蓝分子。HP(DETA-MA)1.2P对染料的装载量随pH值的变化而变化。逐步单封装可以提高HP(DETA-MA)1.2P对染料的装载量。部分封装入HP(DETA-MA)1.2P中的小分子可以通过水洗降低水相中染料的浓度而释放出来;将染料分子释放出来后的HP(DETA-MA)1.2P氯仿溶液可以再次封装染料分子;HP(DETA-MA)1.2P具有可逆释放与重复封装的能力,封装与释放是一个可逆的过程。通过单封装和双封装对比实验考察了主体对客体的选择性,讨论了不同种类染料之间的相互作用对装载量的影响。实验发现当两种染料同时存在时,HP(DETA-MA)1.2P对染料的封装过程中存在协同或竞争两种现象,并设计了逐步双封装实验对协同和竞争两种情况进行了验证。当选择MO和MB作为染料对时,在MO和MB之间是协同关系,UV/vis结果表明MB的存在可以使HP(DETA-MA)1.2P对MO的装载量提高72%,并用1HNMR、TGA、DSC等测试对协同现象进行了验证。考察pH值对双封装的影响的实验表明,pH值的变化对装载量有一定的影响,但是协同封装过程中HP(DETA-MA)1.2P对MO的装载量的提高并不是pH值发生变化的结果,确实是MB的协同作用引起的。当MO和RB、PB、EY、FSS等四种染料分别组成染料对进行双封装实验时,染料对之间存在竞争关系。在RB或PB存在的情况下,MO不能进入HP(DETA-MA)1.2P中,而MO的存在几乎不影响HP(DETA-MA)1.2P对RB或PB的装载;当EY和MO同时存在时,Cload(MO)和Cload(EY)都会降低;当MO和FSS同时存在时,FSS不能进入HP(DETA-MA)1.2P中,且使Cload(MO)降低。DSC、TGA、DLS等结果表明染料分子不只是在大分子之间,确实有染料进入超支化聚合物内部的空穴中。3两亲性超支化聚砜胺的合成及其超分子封装行为研究为了验证超支化聚合物封装染料的普遍性,采用A2型单体二乙烯基砜和BB’2型单体胺乙基哌嗪反应,制得了超支化聚砜胺(HPSA),并采用不同长度的烷基酰氯(戊酰氯、壬酰氯和棕榈酰氯)对超支化聚砜胺进行封端,合成了三种不同烷基末端的两亲性核壳型超支化聚砜胺(HPSAV、HPSAN、HPSAP),并以它们作为主体进行了封装实验。发现它们对刚果红(CR)、甲基橙(MO)、虎红(RB)等水溶性染料具有很强的装载能力,且对同种染料的封装载荷随着末端亲油性烷基链的增长而增大。对于末端为棕榈酰基的HPSAP,平均每个大分子可以捕捉CR和MO分子的数目分别高达41.8和19.4个,远高于文献报道的树枝状聚合物和超支化聚合物对这些染料的装载量,这主要归因于聚砜胺内核的高度亲水性及其与亲油性烷基外壳的极性差。与HP(DETA-MA)1.2P类似,两亲性超支化聚砜胺装载的染料用纯水洗涤可以释放出来。这种高装载性能和可逆性使超支化聚砜胺在药物释放、分子识别和分离以及纳米催化剂和纳米涂料等领域中有着广阔的应用前景。研究了HPSAP对MO/MB、MO/RB、MO/PB、MO/EY、MO/FSS等五对染料对的双封装行为,进一步验证了在HP(DETA-MA)1.2P封装实验中出现的协同双封装和竞争双封装现象。实验证明,与HP(DETA-MA)1.2P作为主体时的情况相似,MO和MB之间存在协同作用,MO的存在大大促进了HPSAP对MB的装载,双封装过程中HPSAP对MB的装载量是单封装时的40倍以上;MO与RB、PB、EY、FSS四种染料之间存在竞争作用,竞争结果与选用HP(DETA-MA)1.2P作为主体时类似。4两亲性超支化聚酰胺胺封装染料前后的自组装行为研究采用两亲性超支化聚酰胺胺HP(DETA-MA)1.2P为自组装前驱体,在固体表面进行溶剂挥发诱导的分子自组装,制得了具有规则蜂窝状形貌的超支化聚合物多孔薄膜。运用场发射扫描电镜、原子力显微镜、透射电镜等仪器对蜂窝状结构进行了表征。蜂窝状孔大小为微米级,具有特殊的双层结构。论文对自组装膜的形貌进行了详细描述,初步提出了可能的自组装机理。膜的制备过程简单,可以在硅片、石英、玻璃、云母片多种固体基片上直接制备,重复性好。这种薄膜有望在生物学(比如生物材料)、光学、电学、模板等领域内得到应用。利用装载有染料的两亲性超支化聚酰胺胺进行自组装,同样得到了蜂窝状自组装多孔薄膜。所得的薄膜能够发射荧光,自组装薄膜的颜色和发光波长可以很方便地通过改变封装的染料及激发波长进行调节,膜的颜色随着所用染料的不同而不同,同一种荧光薄膜在不同激发条件下发射不同的荧光。这是首次将两亲性超支化聚合物的超分子封装与自组装相结合,实现了超分子封装在超分子自组装功能化方面的应用。超分子封装与自组装的结合使自组装更加多样化,为实现多功能性自组装提供了新的方法和策略。本文对超支化聚酰胺胺合成路线的探索为聚酰胺胺类高度支化聚合物的规模化生产提供了一个可行的方案,并为更深入的学术研究及更广泛的应用打下了基础;对超支化聚合物协同封装和在固体基片上的自组装现象的发现使该领域具有更吸引人的前景,启发我们去发现更多超支化聚合物的新现象。更多还原

【Abstract】 Hyperbranched polymers are a kind of highly branched/dendritic macromolecules with three-dimensional architecture. The past 15 years witnessed the remarkable developments of hyperbranched polymers in the aspects of synthesis methods, functionalization and applications. Nevertheless, there are still many problems to be resolved, new phenomena to be found and new directions to be inaugurated in this field. On the basis of the previous works, this thesis aims at solving some of the problems, especially the facile synthesis of water-soluble hyperbranched polymers, representing new research approaches, and finding new phenomena based on the as-prepared hyperbranched polymers. The water soluble hyperbranched poly(amido amine)s (PAMAMs) are readily synthesized by the“couple-monomer methodology”(CMM). The supramolecular encapsulation and self-assembly behaviors of hyperbranched PAMAMs and other water-soluble hyperbranched polymers are investigated in details. The synergistic encapsulation phenomenon is found in the multi-dye encapsulations of hyperbranched polymers. Regular honeycomb-patterned porous films are fabricated by solvent evaporation-induced self-assembly of hyperbranched polymer on solid substrates, including silicon wafer, quartz, glass slide and mica. Encapsulation and self-assembly behavior of hyperbranched polymer are combined and photoluminescent porous films are obtained from the self-assembly of dye-loaded hyperbranched polymer. The details of research methods and results are described as follows.1 Synthesis, modification and characterization of hyperbranched PAMAMs.A series of water soluble aliphatic hyperbranched PAMAMs with similar chemical structure of poly(amido amine) dendrimer were successfully synthesized from commercially available AB and Cn type monomers by one-pot polymerization via the couple-monomer methodology (CMM). The AB type monomer used is methyl acrylate, and Cn are multi-amino compounds such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA) and pentaethylenehexamine (PEHA). The reaction conditions, such as the reaction time, temperature, and pressure, were investigated and feasible conditions were indicated for the synthesis of hyperbranched PAMAM by CMM. Hyperbranched polymers with different terminal groups and properties can be obtained by adjusting the feed ratio of AB to Cn (Rfeed). FTIR, NMR, DSC, and TGA were used to characterize the polymers. It was found that the polymers’properties such as solubility, thermal behavior and encapsulation capability vary with changing the feed molar ratio of AB to Cn. According to the NMR spectra, when the molar ratio of MA to Cn is low, the end groups of the products are amine groups, while when the ratio is high, the end groups are methoxyl groups. The larger the feed molar ratio of MA to Cn, the more are the methoxyl groups and the less the amine groups residual in the polymer. The solubility of hyperbranched PAMAMs is good in chloroform and some polar solvents, including N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl dulfoxide, water, methanol and ethanol, while poor in apolar solvents, such as acetone, tetrahydrofuran and ether. What’s more, the solubility of the products in apolar solvents increases with increasing the molar ratio of MA to Cn. In addition, the products formed from the monomers with different Cn have different solubility in apolar solvents. The products formed from EDA show worse solubility in acetone, THF and ether than those formed from TEPA and PEHA. When the chain length of the Cn type monomer rises, the solubility of its products in apolar solvents gets better. With increasing the Rfeed, Tg will rise gradually and reach the maximum, then will decrease. The products with amine groups as end groups can’t encapsulate dye molecular, while that with methoxyl groups as end groups can encapsulate some dyes molecules.Amphiphilic core-shell hyperbranched PAMAMs with benzoyl or palmitoyl groups were prepared by acidylation of amine groups in hyperbranched PAMAMs with benzoyl chloride or palmitoyl chloride. Modification of amine groups changes the solubility, thermal behaviour, fluorescence, and encapsulation capability of hyperbranched PAMAMs. All acylating products turn insoluble in water. The products end-capped with benzoyl groups display better solubility in apolar solvent, such as acetone and THF, than those without end-capped, and those end-capped with palmitoyl groups become insoluble in polar solvents such as DMF, DMSO, DMAC, and methanol, while soluble in chloroform and THF and partial soluble in ether. The Tgs of the benzoyl end-capped products become much higher than those before modification. The introduction of long chain alkyls endows the palmitoyl end-capped products with crystallization ability. All the PAMAMs without end-capping lost weight less than 5% till 200 oC. The products end-capped with benzoyl or palmitoyl groups showed greater thermal stability, losing no more than 5% weight even up to 300 oC. The hyperbranched PAMAMs were fluorescent and the fluorescence performances were changed after modification. The emitting wavelength can be changed by varying the concentration of the polymer solutions. The encapsulation capability was improved obviously by modification the amine groups by benzoyl or palmitoyl groups.It is expected that the hyperbranched PAMAMs can play an important role in the industrial application fields such as phase-transferring agents, coatings, sewage treatment agents, drug carrier, surfactant, catalyzer, self-assembly building blocks because of their versatility and availability.2 Supramolecular Encapsulation of Amphiphilic Hyperbranched PAMAMs to Dyes.Dye-encapsulation properties of amphiphilic hyperbranched PAMAMs, especially of HP(DETA-MA)1.2P, which was prepared from methyl acrylate and diethylenetriamine (molar ratio feed is 1.2 ) and modification with palmitoyl chloride, were investigated. The amphiphilic hyperbranched PAMAMs can carry water-soluble dyes, including Congo red (CR), methyl orange (MO), methyl blue (MB), fluorescein sodium (FSS), eosin Y (EY), Phloxine B (PB), and rose Bengal (RB), from aqueous solution into chloroform. The loading capacity (Cload) of HP(DETA-MA)1.2P is different to various dyes. Each HP(DETA-MA)1.2P macromolecule can encapsulate about 22.4 Congo red molecules on average, while only 0.63 methyl blue molecules.The loading capacity of HP(DETA-MA)1.2P is dependable on pH value to some extent. Multi-times single-dye encapsulation will help HP(DETA-MA)1.2P load more dye molecules. A part of loaded-dye molecules in the HP(DETA-MA)1.2P macromolecules can be released by reducing concentration of dye aqueous solution of upper layer and the HP(DETA-MA)1.2P chloroform solution can encapsulate dye again when mixed with high concentration dye solution. Such a liberation and encapsulation process is feasible and reversible for HP(DETA-MA)1.2P.The selectivity of host to guests and the influence of interaction between different dyes on loading capacity were investigated by performing comparable single-dye and double-dye experiments. It’s found that there are two kinds of encapsulation cases, synergistic encapsulation or selective encapsulation, when an aqueous solution containing two kinds of dyes is mixed with a chloroform solution of HP(DETA-MA)1.2P. Gradually double-dye encapsulation experiments were carried out to prove the synergistic or competitive interaction between different pair of dyes. There is synergistic interaction between MO and MB molecules and the Cload of HP(DETA-MA)1.2P to MO (Cload(MO)) in the double-dye encapsulations increased about 72% with the cooperation of MB. The synergistic encapsulation phenomenon was confirmed by the measurements of UV/vis, 1HNMR, DSC and TGA on the dye-encapsulated hyperbranched polymers. Investigations on the guest-host supramolecular systems with different pH indicated that the pH value has certain influence on the synergistic encapsulation Cload, but it was not the dominating factor for the synergistic encapsulation. The MB molecules did improve the Cload(MO).There is competitive interaction between MO and RB(or PB, EY, FSS) molecules. MO molecules can’t be encapsulated by the HP(DETA-MA)1.2P with the existence of RB or PB, while the presence of MO molecules almost have no influence on the encapsulation of HP(DETA-MA)1.2P to RB or PB. When MO and EY exist at the same time, both of Cload(MO) and Cload(EY) decrease. When MO and FSS exist at the same time, no FSS molecules can be encapsulated and the Cload(MO) decreases.The results of DSC, TGA and dynamic light scattering (DLS) measurements verify that the transferred dyes were not localized at the space among the macromolecules, but inside the cavity of individual hyperbranched macromolecules.3 Synthesis of Amphiphilic Hyperbranched Poly(sulfone-amine)s and Their Supramolecular Encapsulation Behavior to Dyes.In order to justify the generality of the encapsulation of hyperbranched polymer to dye molecules, hyperbranched poly(sulfone-amine) was prepared from A2 type monomer, divinyl sulfone, and BB’2 type monomer, 1-(2-aminoethyl) piperazine, and three samples of core-shell amphiphilic hyperbranched poly(sulfone-amine) (HPSA), which were synthesized by end-capping of hyperbranched poly(sulfone-amine) with valeryl chloride, nonanoyl chloride and palmitoyl chloride, were used as hosts to encapsulate dyes. They exhibit high capabilities to load water soluble dyes, such as CR, MO and RB. It is found that the longer the terminal hydrophobic chain is, the higher the loading capability would be for the same dye. For the palmitoyl-terminated HPSA, the average number of dye molecules trapped by per macromolecule achieves 41.8 of CR, 19.4 of MO, and 3.0 of RB, respectively. Such high loading capability is considered to attribute to the high water-solubility of the hyperbranched poly(sulfone-amine) core and the large polarity difference between the hydrophilic core and hydrophobic shell. Similar to HP(DETA-MA)1.2P, the loaded dyes can be released from the amphiphilic hyperbranched poly(sulfone-amine) macromolecules by mixing its chloroform solution with pure water. The high loading capability associated with the reversible releasing property would pave the way for the molecular vessels in the application of drug transfer/delivery, selective molecular recognition and separation, nanocatalysis and nanocoating.Double-dye encapsulation experiments also were carried out to investigate the generality of the synergistic and competitive encapsulation phenomena of hyperbranched polymers. Five pairs of dye, including MO/MB, MO/RB, MO/PB, MO/EY and MO/FSS, were also chosen as dyes pair in the double-dye encapsulation experiments. It’s found that the phenomena of synergistic and selective encapsulation also exist when an aqueous solution containing two kinds of dyes is mixed with a chloroform solution of HPSAP. There is also synergistic interaction between MO and MB molecules and Cload of MB can be raised to a 40 folds level of single-dye encapsulation without loss of MO. The interaction between MO and RB(or PB, EY, FSS) molecules is the same as the case when HP(DETA-MA)1.2P was chosen as host.4 Self-assembly of Amphiphilic Hyperbranched PAMAMs and dye-loaded Amphiphilic Hyperbranched PAMAMs.Regular honeycomb-patterned porous films were prepared from solvent evaporation-induced molecular self-assembly of the amphiphilic hyperbranched poly(amido amine), HP(DETA-MA)1.2P, on solid substrates. The organized structure was confirmed by SEM, AFM, and TEM. The honeycomb structure holes are several microns and have special double layer structure. The morphology of the films was described in details and the corresponding self-assembly mechanism was discussed. Such method to fabricate the honeycomb films was convenient and showed good reproducibility on various substrates, such as silicon wafer, quartz, glass slide, freshly cleaved mica. The ordered porous films may have potential applications in the filed of biology (biomaterials), photonics, electronics, and patterned templates.The similar films have also been prepared from dye-loaded amphiphilic hyperbranched PAMAM. What’s more, the films were fluorescent. The fluorescence of the assembled functional films can be adjusted by the encapsulated dyes, and the emission peak can be tuned by the excitation wavelength. This novel strategy greatly enlarges the assembling diversity, makes versatile complex patterned film easily accessible, paves the way for multi-substance non-molecular self-assembly that allows one or more substance disperse and distribute in another one at the molecular level, and opens a straightforward route to functionalization of self-assembly structures. This is the first time to combine the supramolecular encapsulation behavior with self-assembly of the amphiphilic hyperbranched polymers and make self-assembly films functionalized by encapsulation.The facile and large-scale synthesis of hyperbranched PAMAMs paves the way for their academic research in a deeper level and wide range of applications. The findings of synergestic encapsulation and substrate-supported self-assembly of amphiphilic hyperbranched polymers promise the fascinating future of this field and enlighten us to discovery more new phenomena based on hyperbranched polymers.更多还原