超支化聚合物化学键合毛细管电泳柱的制备及其对蛋白质的分离行为

分别合成了以三羟甲基丙烷和季戊四醇为核的超支化聚(胺-酯),并对其进行了红外测定、羟值测定、粘度测定等表征。采用化学键合方法将其涂于毛细管内壁,并测定涂层柱的电渗流以及对碱性蛋白质的分离能力,结果表明,涂层柱能有效地抑制碱性蛋白质在毛细管内壁上的吸附,大大降低电渗流;以三羟甲基丙烷为核的超支化聚(胺-酯)涂层柱的塔板数达105/m,而以季戊四醇为核的超支化聚(胺-酯)涂层柱的分离柱效更高,塔板数达107/m。实验结果表明这两类涂层柱都具有较好的分离效果和稳定性。     

不同代数超支化聚胺酯的制备及其在钕纳米粒子制备中的应用

以N，N-二羟乙基-3-胺基丙酸甲酯单体和季戊四醇（核）为原料，采用“准一步法”合成了具有端羟基的超支化聚胺酯（HPAE）。采用凝胶色谱、红外光谱、核磁共振和热重分析等对其进行了结构表征及性能探究。再以HPAE封装稀土粒子钕（Nd），制备出Nd复合纳米粒子，透射电镜（TEM）分析结果表明：随着HPAE代数增大，Nd纳米颗粒粒径越均匀，分散度越好。     

NOVEL HYPERBRANCHED POLY（AMINE-ESTER） FILMS： PREPARATION,CHARACTERIZATION AND PROPERTIES

Crosslinked film of hyperbranched poly(amine-ester) (HPAE) was prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde (GA). Atom force microscope (AFM) and scanning electron microscope (SEM) reveals that they have smooth surfaces, dense and homogenous matrices. It was found that the water static contact angle is smaller than 41.7°, the tensile strength is higher than 8.9 MPa, the elongation at break is higher than 5.1%, the swelling degree is higher than 42% in water, and the Bovine hemoglobin (Hb) adsorption is relatively low. These results indicate that the crosslinked HPAE films might have some potential applications in many areas.     

Nanoparticle carriers based on copolymers of poly(ε-caprolactone) and hyperbranched polymers for drug delivery

Novel amphiphilic copolymers based on poly(ε-caprolactone) (PCL) and hyperbranched poly (amine-ester) (HPAE) with various compositions were synthesized. The amphiphilic copolymers can self-assemble into nanoscopic micelles and their hydrophobic cores can encapsulate doxorubicin (DOX) in aqueous solutions. The DOX-loaded HPAE-co-PCL nanoparticles diameter increased from 121 to 184 nm with the increasing PCL segment in the copolymer composition. An in vitro study at 37°C demonstrated that DOX-release from nanoparticles at pH 5.0 was much faster than that at pH 7.4. The cytotoxicity for HeLa cells study demonstrated that DOX-loaded HPAE-co-PCL nanoparticles exhibited the anti-tumor effect was enhanced significantly, suggesting that the DOX-loaded HPAE-co-PCL nanoparticles have great potential as a tumor drug carrier.     

Preparation and stability of copper particles formed using the template of hyperbranched poly(amine-ester)

The sixth-generation hydroxyl-ended hyperbranched poly(amine-ester) (G6-OH) was investigated as template in formation and stabilization of copper nanoparticles. Ultra-violet spectra and transmission electron microscope were adopted to characterize absorption properties of G6-OH(Cu²⁺)_n complex and the morphology of the formed particles (G6-OH(Cu)_n), respectively. The template and stabilization functions of G6-OH were compared with di-block copolymer micelles and dendrimers having similar structure. It was found that the hyperbranched polymers could act as the templates for the preparation of copper particles. The size of the formed copper particles increased with Cu²⁺/Gn-OH molar ratio. Besides, the oxygen influenced the chemistry stability of copper particles greatly.     

Preparation and pervaporation properties of crosslinked hyperbranched poly(amine-ester) membranes

Crosslinked hyperbranched poly(amine-ester) (HPAE) membranes were prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde (GA). The crosslinked HPAE membranes showed high reactivity and good hydrophilicity. The crosslinking degree was investigated by Fourier transformation infrared spectra (FT-IR). Atom force microscope (AFM) and scanning electron microscope (SEM) reveals that the crosslinked HPAE films have smooth surfaces, dense and homogenous matrices. The swelling degree of the membrane was higher in water than that in isopropanol. From the permeation of pure water through the HPAE membrane, the effect of hydroxyl/aldehyde group ratio on the permeation flux and separation factor was investigated. The results indicated that the permeation flux increase was accompanied with the separation factor decrease if the water concentration increased in the feed solution.     

Hyperbranched Polyurethane Acrylate Applied to UV Curable Flame Retardant Coatings

UV curable hyperbranched prepolymers based on amine-ester, ester-amide and ether-amide started with AB_2-type monomers have been prepared by the authors. A series of work on allyl ether maleate hyperbranched polyesters for UV curing coatings by Hult and his colleagues has been reported. However, the UV cured films from those materials are all flammable when attached to fire without addition of flame retardants. In this work, a new kind of hyperbranched polyurethane acrylate containing phosphorus     

以四重氢键结合的超支化聚合物及其涂层材料

合成了以Upy(2-ureido-4[1H]-pyrimidone)封端的超支化聚合物并研究其涂层材料性能.首先在哌嗪与三羟甲基丙烷三丙烯酸酯摩尔比2.25∶1条件下,合成了端仲胺基超支化聚(酯-胺)(HPEA),进而在仲胺基/异氰酸酯基官能团比1∶0.3、1∶0.4和1∶0.5下,通过HPEA与单异氰酸酯基甲基异胞嘧啶反应,合成了一系列带有Upy基元的改性超支化聚合物.由于Upy基元间形成了自识别四重氢键,改性聚合物比HPEA具有更高的玻璃化转变温度和热分解温度,并且改性聚合物涂层具有优良的力学性能,这表明分子间强氢键相互作用可有效改善超支化聚合物的性能.     

超支化聚(胺酯)的分子设计及其制备

以丙烯酸甲酯和二乙醇胺为原料由Michael加成反应制得N ,N 二羟乙基 3 胺基丙酸甲酯单体 ,再用“准一步法”和“发散法”使之与 1 ,1 ,1 三羟甲基丙烷 (核 )反应合成一种新型超支化聚 (胺 酯 ) .以核磁共振和元素分析方法对N ,N 二羟乙基 3 胺基丙酸甲酯单体的分子结构进行了表征 .GPC测定表明合成的超支化聚 (胺 酯 )分子量分布窄 ,具有单分散性 ;粘度小于同分子量的线形分子 ;耐热性能较好 ,失重温度高于2 0 0℃ .     

New Approach to the Formation of Physically Adsorbed Capillary Coatings Consisting of Hyperbranched Poly(Ethylene Imine) with a Maltose Shell to Enhance the Separation of Catecholamines and Proteins in CE

Core–shell-type polymers based on a hyperbranched (hb) poly(ethylenimine) core and a shell with a variable maltose content were applied as coating materials for fused silica capillaries. A new, simple, fast, and reproducible way of modifying the capillary walls through the physical adsorption of the core–shell-type polymers using a Cu²⁺ support was developed. The coating created by this method was found to be very stable compared to the coating created using a solution of the polymer only. Capillaries modified with the core–shell-type polymers were tested by applying them to the electrophoretic separation of catecholamines and proteins. The modified capillaries showed high efficiencies (up to 800,000 theoretical plates per meter for lysozyme) and separation selectivities. The highest efficiency was achieved using capillaries modified with the polymer containing the lowest content of maltose in the shell and the most accessible positively charged core. Various online concentration techniques were also tested as a means to lower detection limits further, making it possible to analyze proteins in biological fluids (saliva) as well as catecholamines in human urine after SPE using activated alumina.     

具有四重氢键识别基元超支化聚合物的特殊流变行为

在羟基与异氰酸酯基官能团比1∶0.13、1∶0.25、1∶0.33和1∶0.5下,通过端羟基超支化聚(酯-胺)(HPEA)与单异氰酸酯基甲基异胞嘧啶的反应,合成了一系列以脲基嘧啶酮(ureidopyrimidinone,Upy)单元封端的超支化聚合物(HPEA-U).由于Upy单元间形成自识别四重氢键作用,Upy改性聚合物的熔融流变行为表现出了明显的温度和频率依赖性.随着Upy含量增加,聚合物的解缔温度逐渐增加.在低频范围内,随着频率增大,其表观黏度降低,储能模量增加.在临界频率以上,随着频率增大,出现剪切变稠及储能模量迅速降低现象.基于Upy微区结构的剪切破坏及游离Upy单元间的氢键结合,对这种特殊的流变行为进行了解释.     

Synthesis and characterization of novel hyperbranched poly(imide silsesquioxane) membranes

A new family of hyperbranched polymers with chemical bonds between the hyperbranched polyimide and polysilsesquioxane network was synthesized by the reaction of an amine‐terminated aromatic hyperbranched polyimide with 3‐glycidoxypropyl trimethoxysilane, followed by hydrolysis and polycondensation in the presence of an acid catalyst. The hyperbranched poly(imide silsesquioxane) membranes were fabricated by the casting the aforementioned polymer solution onto a NaCl optical flat, which was followed by heating at 80 °C for 24 h. The membranes were characterized by Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, N₂ adsorption and desorption, and CO₂ adsorption and desorption. The presence of covalent bonds between the hyperbranched polyimide and polysilsesquioxane segments had a significant effect on the properties of the membranes. N₂ adsorption–desorption isotherms for these membranes showed surface areas of 6–16 m²/g, whereas CO₂ adsorption–desorption isotherms showed much higher surface areas in the range of 106–127 m²/g. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3736–3743, 2003     

Catalytic water dissociation using hyperbranched aliphatic polyester (Boltorn series) as the interface of a bipolar membrane

The effect of hyperbranched aliphatic polyester (Boltorn series) on the water dissociation in bipolar membranes was firstly investigated in this paper. The bipolar membranes were prepared by immersing the anion exchange layer in a hyperbranched aliphatic polyester solution and then coating on the layer a polyphenylene oxide (SPPO) solution. The SEM observations proved the existence of hyperbranched aliphatic polyester at the membrane intermediate layer. The adsorption amount was evaluated by the oxygen content via XPS. The junction thickness of the prepared bipolar membrane was determined by electrochemical impedance spectroscopy (EIS), and the membrane performances were evaluated by current-voltage curves. The results showed that the amount and generation of Boltorn series, and temperature all affected I-V behaviors of the fabricated bipolar membranes, and the former two played the critical role. These effects were explained on the basis of the water dissociation theory and the characteristics of hyperbranched aliphatic polyester.     

端基结构对超支化聚合物静电吸附自组装行为的影响

研究了3种具有相同骨架结构、不同端基的超支化聚合物与线型聚阳离子(PDAC)的静电吸附自组装.结果表明,超支化聚合物的组装过程与线型弱酸聚合物相似,都受溶液pH值与无机盐浓度的影响,但影响程度随端基结构不同而变化.此外,对以超支化聚合物为最外层的不同自组装膜的表面形貌及接触角进行了表征,其表面形貌及亲水性随端基结构的不同而不同.     

Growing hyperbranched polyglycerols on magnetic nanoparticles to resist nonspecific adsorption of proteins

Hyperbranched polyglycerols were grown from magnetic nanoparticles (MNPs) via surface-initiated anionic ring-opening polymerization of glycidol. The modified MNPs were characterized by using TEM, XPS, TGA and FTIR. Hyperbranched polyglycerols resist the nonspecific adsorption of proteins on magnetic nanoparticles. The capability of hyperbranched polyglycerols is comparable favorably with the performance of methyloxy poly(ethylene glycol) (a linear mPEG with a molecular weight of 750) in resisting the adsorption of proteins.     

Effect of sodium dodecyl benzene sulfonate to the displacement performance of hyperbranched polymer

Experimental studies were conducted to realize displacement performance effect of anionic surfactant sodium dodecyl benzene sulfonate (SDBS) on hyperbranched poly(AM/AA/AMPS/GA), which was successfully synthesized via free radical polymerization using modified dendritic functional monomer (GA), acrylamide (AM), acrylate (AA), and 2-acrylamido-2-methyl propane sulfonic acid (AMPS). Compared with individual polymer, SP (surfactant polymer) binary systems showed lower apparent viscosity, interfacial tension, and hydrodynamic radius as the result of the electrostatic repulsion between the tail end of hydrophilic polymer branched chain and the head of the surfactant. It was found from abundant static adsorption and dynamic retention tests that the values of static adsorption and dynamics retention of SDBS which is mixed with hyperbranched polymer decrease due to the competitive interaction. However, unlike this phenomenon, SDBS would heighten the dynamic retention value of poly(AM/AA/AMPS/GA), resulting in addition of residual resistance factor. Oil displacement experiment indicated that SP solutions have greater capability of enhance oil recovery than individual polymer under same conditions.     

Synthesis of novel star-like hyperbranched polymers with poly(amido amine) core and poly(l-lysine) shell

Hyperbranched poly(amido amine)s containing vinyl and hydroxyl groups were successfully synthesized via Michael addition polymerization of triacrylamide (TT) and 3-amino-1,2-propanediol (APD) with equal molar ratio in feed. ¹H, ¹³C and HSQC NMR techniques were used to clarify the structure of hyperbranched polymers and polymerization mechanism. The Michael addition reaction of hyperbranched poly(1TT-1APD)s with primary amine-terminated poly(ε-benzyloxycarbonyl-l-lysine)s [PLys(Z)] yielded a star-like hyperbranched polymers with poly(1TT-1APD) core and Plys(Z) shell. The Z groups in PLys(Z) were removed under acidolysis, and thus star-like hyperbranched polymers with hydroxyl groups inside and primary amine groups outside were obtained successfully.     

Influence of polyelectrolyte capillary coating conditions on protein analysis in CE

CE of biomolecules is limited by analyte adsorption on the capillary wall. To prevent this, monolayer or successive multiple ionic‐polymer layers (SMILs) of highly charged polyelectrolytes can be physically adsorbed on the inner capillary surface. Although these coatings have become commonly used in CE, no systematic investigation of their performance under different coating conditions has been carried out so far. In a previous study (Nehmé, R., Perrin, C., Cottet, H., Blanchin, M. D., Fabre, H., Electrophoresis 2008, 29, 3013–3023), we investigated the influence of different experimental parameters on coating stability, repeatability and peptide peak efficiency. Optimal coating conditions for monolayer and multilayer (SMILs) poly(diallyldimethylammonium) chloride/ poly(sodium 4‐styrenesulfonate) coated capillaries were determined. In this study, the influence of polyelectrolyte concentration and ionic strength of the coating solutions, and the number of coating layers on coating stability and performance in limiting protein adsorption was carried out. EOF magnitude and repeatability were used to monitor coating stability. Coating ability to limit protein adsorption was investigated by monitoring variations of migration times, time‐corrected peak areas and separation efficiency of test proteins. The separation performance of polyelectrolyte coatings were compared with those obtained with bare silica capillaries.     

Immobilized hyperbranched glycoacrylate films as bioactive supports

[Image: see text] We report on the low-pressure plasma immobilization, characterization and application of thin films of hyperbranched glycoacrylates, poly(3-O-acryloyl-alpha,beta-D-glucopyranoside) (AGlc), on PTFE-like fluorocarbon surfaces. This method is an efficient and versatile way to immobilize sugar-carrying branched acrylates as thin films of approximately 5 nm thickness on polymeric substrates while the functional groups and properties of the immobilized molecules are largely retained. The extent of poly(AGlc) degradation during plasma immobilization was investigated using FTIR-ATR spectroscopy and XPS. The thickness and topography of the immobilized films were characterized using spectroscopic ellipsometry and SFM, respectively. Studies of protein adsorption, as well as cell adhesion and proliferation on the poly(AGlc) surfaces, showed that these materials are suitable for the control of biointerfacial phenomena. Fluorescence images of fibronectin adsorbed on to the branched glycoacrylate with a mask.     

Novel hot-melting hyperbranched poly（ester-amine） bearing self-complementary quadruple hydrogen bonding units

Hyperbranched poly（amine-ester）s bearing self-complementary quadruple hydrogen bonding units display excellent mechanical and temperature-dependent melt rheological properties, which make them suitable as novel hot-melting materials.