PEO-PPO-PEO嵌段共聚物胶团化及其应用研究进展

对PEO-PPO-PEO嵌段共聚物在水溶液中形成胶团过程进行了综述.阐明了温度、浓度、嵌段共聚物的分子量和EO/PO比率等因素对PEO-PPO-PEO嵌段共聚物的临界胶团浓度、临界胶团温度、胶团的聚集数以及胶团的结构等的影响.简介了小角中子散射、FTIR光谱、自洽均匀场晶格理论等用于研究PEO-PPO-PEO嵌段共聚物的胶团化机理.重点介绍了PEO-PPO-PEO嵌段共聚物在介孔材料、生化分离、界面吸附、增溶有机物等方面的应用.     

由聚氧乙烯和聚4'''-酰胺基对四联苯-2,6-二甲酰对苯二胺构筑的OAO形三元嵌段共聚物在N、N-二甲基甲酰胺中的自组装结构模拟

利用耗散粒子动力学模拟方法,研究了由拉胀聚合物聚4''-酰胺基对四联苯-2,6-二甲酰对苯二胺(A)与聚氧乙烯(PEO)组成的OAO形三元嵌段共聚物在溶剂N、N-二甲基甲酰胺(DMF)中的自组装行为,探究了共聚物浓度和链段A的长度对三元嵌段共聚物自组装结构的影响。结果表明,由聚4''-酰胺基对四联苯-2,6-二甲酰对苯二胺(A)与聚氧乙烯(PEO)构筑的线型嵌段共聚物在溶剂N、N-二甲基甲酰胺(DMF)中的自组装将形成形态各异的球状、柱状、毛刷型以及"球刺"状胶束等结构;随着共聚物浓度的增加,球状胶束结构消失,逐渐演变为柱状以及毛刷型结构;随着链段A长度的增加,共聚物形成的球状胶束结构慢慢转变为"球刺"状胶束。     

PEO-b-PS两亲性嵌段共聚物的合成与表征

以PEO-Br为大分子引发剂,CuBr/2-2’-联吡啶为催化体系,采用原子转移自由基聚合(ATRP)方法制得了一系列分子量可控且分子量分布窄的两亲性嵌段共聚物,通过1H-NMR、GPC、DSC等测试手段对其进行了表征,研究结果表明嵌段共聚物随着聚氧乙烯含量的降低,结晶度(Xc)、结晶熔融温度(Tm)、结晶温度(Tc)降低;当共聚物中聚氧乙烯的含量降为45%时,嵌段共聚物已无结晶现象。     

聚乳酸/聚氧乙烯-聚氧丙烯醚嵌段共聚物共混体系的性能

采用熔融共混制备聚氧乙烯–聚氧丙烯醚嵌段共聚物增塑聚乳酸,研究聚氧乙烯–聚氧丙烯醚嵌段共聚物用量对聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系流变性能、力学性能、热性能和微观结构的影响。当添加聚氧乙烯–聚氧丙烯醚嵌段共聚物的质量分数为20%时,聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系的熔体流动速率为15.6g/(10min),比未增塑时提高约9倍,断裂伸长率为341.86%,撕裂强度为23.7N/cm,拉伸强度为44.5MPa,玻璃化转变温度从纯聚乳酸的60.1℃降到26.9℃。随着聚氧乙烯–聚氧丙烯醚嵌段共聚物用量的增加,共混体系的拉伸强度先下降后升高,断裂伸长率呈上升趋势,撕裂强度先下降后上升最后渐趋于稳定,聚乳酸链段的活动能力增强,增塑效果明显。扫描电子显微镜分析表明,当聚氧乙烯–聚氧丙烯醚嵌段共聚物质量分数≥12%时,共混体系脆冷断面的褶皱、粗糙度和裂纹明显增加,吸收能量能力增强,表现为断裂伸长率和撕裂强度提高。     

水性涂料

正201604012聚碳酸酯/聚氧乙烯嵌段共聚物及其水性组合物的制备及应用:WO2015 170 374[国际专利申请,日]/日本:Asahi Kasei Chemicals Corporation(Miyazaki,Takayuki).-2015.11.12.-61页.-2014/JP62 270(2014.03.07)题述嵌段共聚物由聚碳酸酯链段和聚氧乙烯链段组成,且共聚物的端基为羟基。其中,聚碳酸酯链段的结构式为(ROCO_2)_m(R表示支化或非支化C_(2-15)脂肪烃、脂环烃、芳香烃;m表示数值);聚氧乙烯链段结构式为     

嵌段共聚物聚苯胺-聚乙二醇-聚苯胺水溶液中自组装的介观模拟

用耗散颗粒动力学(DPD)模拟了嵌段共聚物PAn-PEG-PAn在水溶液中的介观相分离。考察了浓度和嵌段比对嵌段共聚物自组装影响的规律,获得了实验难以观察到的介观层次上各嵌段在球面分布情况,并重点研究了嵌段共聚物在稀溶液中自组装成球体的特征和原理。随着PAn链段的摩尔分数的增加,模拟先后获得三种球体,一是憎水段PAn为外壳、亲水段PEG为内核的球体;二是中心为亲水段PEG,中间层为憎水段PAn,最外层是亲水段PEG的三层壳核型球体;三是以亲水段PEG为外壳、憎水段PAn为内核的球体。在高浓度下,水在体系中呈现出有趣的分布现象,即水大部分聚集呈柱状或球状,少部分均匀分散在嵌段共聚物中。结论对实验可以起辅助和指导作用。     

N-异丙基丙烯酰胺嵌段共聚物自组装行为研究进展

具有两亲性和温敏性的嵌段共聚物在选择性溶剂中能够自组装形成独特的微米级甚至纳米级有序结构,具有广泛的潜在应用。聚N-异丙基丙烯酰胺（PNIPAM）是一种典型的温敏性高分子材料,其分子链表现出独特的温敏行为,关于其修饰改性以及自组装行为的研究一直广受关注。以PNIPAM为基点介绍其嵌段共聚物的自组装行为,详细综述影响其行为的诸多因素如组成、分子量、外界刺激条件等,介绍其在生物医药、催化反应等方面的应用,并对其未来的发展方向进行了展望。     

Pluronic-PEI纳米凝胶的制备

<正>聚氧乙烯-聚氧丙烯-聚氧乙烯是一类具有两亲性的三元嵌段共聚物,通常记为:EOx-POy-EOx,商品名为普朗尼克Pluronic,目前BASF公司已经对其实现了商业化生产。通过调节聚氧乙烯PEO和聚氧丙烯PPO的聚合度x、y的比值,可以生产出一系列性能各异的Pluronic产品,以适应不同的生产     

合成二维六方苯环桥联型杂化介孔材料的新方法

以苯基桥联硅氧烷[1,4-bis(trimethoxysily1)benzene,BTSB]和三嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯(EO20PO70EO20,P123)分别作为硅源和模板剂,在无酸体系中利用ZrOCl2-K2SO4的协同作用方便制得二维六方苯环桥联型杂化介孔材料(periodic mesoporou...     

N-异丙基丙烯酰胺嵌段共聚物自组装行为研究进展

具有两亲性和温敏性的嵌段共聚物在选择性溶剂中能够自组装形成独特的微米级甚至纳米级有序结构,具有广泛的潜在应用。聚N-异丙基丙烯酰胺(PNIPAM)是一种典型的温敏性高分子材料,其分子链表现出独特的温敏行为,关于其修饰改性以及自组装行为的研究一直广受关注。以PNIPAM为基点介绍其嵌段共聚物的自组装行为,详细综述影响其行为的诸多因素如组成、分子量、外界刺激条件等,介绍其在生物医药、催化反应等方面的应用,并对其未来的发展方向进行了展望。     

利用Pluronic嵌段共聚物的增溶胶束超滤分离技术

增溶胶束超滤 (MEUF)是新型膜分离技术 ,但迄今仅利用普通烷烃链表面活性剂作为其胶束物质 ,由于这些表面活性剂单体相对分子质量低 ,形成的胶束较小 ,不仅难以有效增溶有机分子 ,还可能透过超滤膜造成对水体的二次污染。聚氧乙烯 -聚氧丙烯 -聚氧乙烯三嵌段共聚物 (Pluronics)是一类重要的功能高分子 ,在合适条件下 ,它们在水溶液中聚集生成具有很大内核的胶束 ,这种胶束能有效增溶水溶液中的有机污染物。其次 ,Pluronic共聚物分子单体的大相对分子质量使其容易被超滤膜隔离 ,加上Pluronic共聚物无毒无刺激性 ,因而这类新型功能高分子适合用于增溶胶束超滤方法 ,实现对水体有机污染物的分离。综述Pluronic嵌段共聚物的胶束化、胶束结构、胶束增溶以及在增溶胶束超滤分离技术中的应用     

Effect of PEO-PPO-PEO structure on the compressed ethylene-induced reverse micelle formation and water solubilization

Some of the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) tri-block copolymers aggregate in p-xylene upon addition of ethylene and form reverse micelles at higher temperature at which the reverse micelles cannot be formed without addition of compressed ethylene. An abrupt increase of water solubilization is observed at a certain ethylene pressure. The effects of surfactant structure, such as the ratio of EO (EO weight percent) and the molecular mass, on the copolymer micellization and the solubilization of water in such systems are studied. For the copolymers with the same length of PO block, higher EO ratios facilitate the reverse micelle formation. However, as the EO ratio reaches 70%, it cannot form reverse micelles because the hydrophilicity is too high. For the copolymers with same composition, higher molecular weight is favorable to forming the reverse micelle due to the hydrophilic and folding effects, respectively. The reverse micelle solution can solubilize water with W₀ (molar ratio of water to EO segment) up to 4.1.     

The influence of hydrophobic substitution on self-association of poly(ethylene oxide)-b-poly(n-alkyl glycidyl carbamate)s-b-poly(ethylene oxide) triblock copolymers in aqueous media

A series of amphiphilic poly(ethylene oxide)-b-poly(n-alkyl glycidyl carbamate)s-b-poly(ethylene oxide) triblock copolymers were synthesized by reaction between poly(ethylene oxide)-b-polyglycidol-b-poly(ethylene oxide) precursor copolymer and four n-alkyl isocyanates: ethyl, propyl, butyl and pentyl. After dissolution in water at room temperature the copolymers spontaneously form micelles. The critical micellization concentrations were determined by UV-VIS spectroscopy. The dimensions of the micelles, the aggregation numbers, and in some cases the micellar shape were determined by dynamic and static light scattering in a relatively broad temperature range. Special attention has been paid to the influence of the number of the carbon atoms in the alkyl chains, and respectively, the relative hydrophobicity of the middle block upon the self-association process. Clouding transition was observed for all of the copolymers, the clouding point being dependent upon the length of the alkyl chain.     

Pluronic嵌段共聚物胶束化行为及其胶束增溶

两亲性质的Pluronic嵌段共聚物在合适条件下能自发形成内核很大的稳定胶束 ,其胶束化行为复杂 ,初步的研究深化了对两亲分子自组织机理的认识。实验发现这类胶束具有很强的增溶油溶性物质的能力 ,由于这些分子单体和胶束化行为的特点 ,可望利用这类嵌段共聚物实现在增溶应用场合中的突破。综述Pluronic嵌段共聚物的胶束化行为和胶束增溶规律的当前研究进展     

Novel non-ionic block copolymers tailored for interactions with phospholipids

The bulk of literature on phospholipid membrane interactions with non-ionic amphiphilic block copolymers deals with ABA triblock copolymers of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide). This is partially the result of their commercial availability. In recent years novel block copolymers have been synthesized and their interactions with phospholipids structured as Langmuir monolayers, liposomes, bilayer lipid membranes, tethered bilayers, and living cells have been studied. This review describes some new block copolymers with potential to interact with phospholipids. There is a tremendous progress in synthesis of amphiphilic block copolymers triggered by new controlled polymerization techniques as atom transfer radical polymerization or nitroxide mediated polymerization and by the possibility to ‘click’ preformed blocks together using quantitative reactions of functional endgroups. A special focus is given to novel water soluble amphiphilic triblock copolymers of poly(glycerol monomethacrylate)-b-poly(propylene oxide)-b-poly(glycerol monomethacrylate) and their interactions with phosphatidylcholine lipids. Also block copolymers containing hydrophobic blocks with perfluoroalkyl groups are discussed since they are special in a sense that their fluorophilic blocks are neither hydrophilic nor oleophilic as this is the case for conventional amphiphilic block copolymers. Experimental methods to study block copolymer–phospholipid interactions are summarized and selected results based on special experimental techniques such as isothermal titration calorimetry, infrared reflection absorption spectroscopy and ion conductance are presented. This work is intended to convey a better quantitative understanding of amphiphilic block copolymers used for in vitro and in vivo experiments in medicine and pharmacy.     

Dissipative particle dynamics study on the multicompartment micelles self-assembled from the mixture of diblock copolymer poly(ethyl ethylene)-block-poly(ethylene oxide) and homopolymer poly(propylene oxide) in aqueous solution

Dissipative particle dynamics (DPD) method is applied to model the self-assembly of diblock copolymer poly(ethyl ethylene)-block-poly(ethylene oxide) (PEE-b-PEO) and homopolymer poly(propylene oxide) (PPO) in aqueous solution. In this study, several segments are coarse-grained into a single simulation bead based on the experimental density. For the self-assembly of pure diblock copolymer PEE-b-PEO in dilute solution, the DPD simulation results are in good agreement with experimental data of micelle morphologies and sizes. The chain lengths of the block copolymers and the volume ratios between PPO and PEE-b-PEO are varied to find the conditions of forming multicompartment micelles. The micelles with core-shell-corona structure and the micelles with two compartments are both formed from the mixture of PEE-b-PEO and PPO in aqueous solution.     

Solid-state NMR characterization of unsaturated polyester thermoset blends containing PEO-PPO-PEO block copolymers

First, the NMR method proposed in our previous work was improved to provide more accurate measurement of interphase thickness in multiphase polymers. Then the improved method, in combination with other techniques, was applied to elucidate the phase behavior, miscibility, heterogeneous dynamics and microdomain structure in thermoset blends of unsaturated polyester resin (UPR) and amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer. The experimental results were compared with those of epoxy resin (ER)/PEO-PPO-PEO blends to systematically elucidate the influence of binary polymer-polymer interaction on the phase behavior, domain size and especially the interphase thickness in thermoset blends of UPR and ER, respectively, with the same PEO-PPO-PEO triblock copolymer. It was found that UPR/PEO-PPO-PEO exhibits strong phase separation with considerably small interphase, and only a small fraction of PEO is mixed with UPR. Whereas ER/PEO-PPO-PEO exhibits weak phase separation with thick interphase, and a large amount of PEO is intimately mixed with ER. It was suggested that the thermodynamic interaction between the block copolymer and cross-linked thermoset resin is one of the key factors in controlling the phase behavior, domain size and interphase thickness in these blends. These NMR results are qualitatively in good agreement with the previous theoretical prediction of interphase properties between two immiscible polymers. Our NMR works on different thermoset blend systems with weak and strong microphase separations clearly demonstrate that the improved NMR method is a general and useful method for measuring the interphase thickness and elucidating the phase behavior and subtle microdomain structure in multiphase polymers with detectable heterogeneous dynamics.     

Self-assembly behavior of rod–coil–rod polypeptide block copolymers

Self-assembly behavior of rod–coil–rod poly(γ-benzyl-l-glutamate)-b-poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamate) (PBLG-b-PEG-b-PBLG) triblock copolymers with various PBLG block lengths in aqueous solution was investigated. The PBLG-b-PEG-b-PBLG triblock copolymers are able to self-assemble into vesicles when PBLG block length is relatively short. Meanwhile, the initial polymer concentration was found to have influence on the self-assembly. Giant vesicles can be observed when the initial concentration is high. Dissipative particle dynamics (DPD) simulations about the vesicles revealed that the rigid rod blocks could be aligned parallelly with each other to form the monolayer vesicles wall. When the PBLG block length in the PBLG-b-PEG-b-PBLG triblock copolymers increases, the aggregate morphologies were observed to transform from vesicles to spherical micelles. Based on the experimental and simulation results, we proposed a possible mechanism of the morphological transitions of the rod–coil–rod triblock copolymer aggregates.     

Self-assemblies formed by four-arm star copolymers with amphiphilic diblock arms in aqueous solutions

The self-assembly of two star copolymers, each consisting of four diblock arms of either poly(?-caprolactone)-block-poly(ethylene oxide), PCL-PEO, or polylactide-block-poly(ethylene oxide), PLA-PEO, with PEO blocks in the centers of the stars, have been studied by a combination of light scattering, atomic force microscopy, fluorometry and ¹H NMR spectroscopy. Results of the study show that despite the very similar architecture of both star copolymers, the structures of their self-assembled nanoparticles differ. Unlike the (PLA-PEO)₄ star copolymer which forms core/shell flower-like micelles, the association of the (PCL-PEO)₄ copolymer leads to large micellar aggregates in which individual micelles are interconnected by shared unimers, having joint coronas formed by hydrophilic centers of the stars.     

Solubilization of Aromatic Hydrocarbons in Ethylene Oxide-Propylene Oxide Triblock Micelles: Location of Solubilizate and its Effect on Micelle Size from 2D NMR and Scattering Techniques

The solubilization of benzene and toluene in micellar solutions and the effects on the micellization and micelle size of ethylene oxide-propylene oxide triblock copolymers were investigated by dynamic light scattering (DLS), small angle neutron scattering (SANS), and 2D NMR spectroscopy. The copolymeric surfactants have the same size as the middle hydrophobic polypropylene oxide block (Mol. Wt. 3250) and varying polyethylene oxide end blocks (30, 40 and 50%). The solubilization and the properties of the micelles in the presence of the solubilizates were investigated; the results reveal that the more hydrophobic copolymer showed better solubilization. The cloud points of the copolymers decreased in the presence of oils; the depression in the cloud point is due to the formation of an electron donor–acceptor complex. DLS shows that the effect of benzene is dominated at high oil concentration. SANS data show that the micelles remain spherical in shape and that the micellar core size does not change with higher benzene concentration; observed changes in the low scattering vector region could be because of some small amount of benzene clusters formed at higher benzene concentration. Finally, the locus of solubilization of the oils in the copolymer micelles was determined via 2D NMR experiments. In all cases, significant nuclear Overhauser effect spectroscopy (NOESY) cross peaks were observed that appeared to correlate well with the expected loci of these solubilizates in micelles. Hence, the noninvasive NOESY technique provides important information on the location of the aromatic solubilizates in these copolymer micelles that depends on the structure of the oils.