Urethane Acrylate Nonionomer Research Articles

Surface Properties of Structure-Controlled Silica Films Prepared Using Organic-Inorganic Hybrid Solutions

Silica films with various microstructures were fabricated using organic-inorganic (O-I) hybrid solutions containing a mixture of silica sols, polymethylmethacrylate (PMMA), and urethane acrylate nonionomer (UAN) as an amphiphilic polymer, The O-I hybrid solutions were prepared with various UAN:PMMA and polymer/solvent ratios, then spin-coated on glass and calcinated at 450 °C to produce silica films with various microphase-separated structures. For higher UAN and PMMA concentrations, the silica films showed spherical inorganic domains dispersed over the surface, while many pores were formed in the films with lower polymer contents (observed using scanning electron microscopy). The surface hydrophobicity of the silica films was determined using water contact angle measurements. After surface modification using (1H, 1H, 2H, 2H-perfluorooctyl)trichlorosilane solution, the hydrophobicity of films with a highly microphase-separated structure increased significantly, and all surface-modified films showed increasing hydrophobicity with increasing polymer content. Furthermore, pencil scratch hardness tests showed that the silica films formed on glass substrates could withstand the 5H scratch, test even after surface modification.

High ionic selectivity of low permeable organic composite membrane with amphiphilic polymer for vanadium redox flow batteries

Blend membranes comprising sulfonated poly(ether ether ketone) (sPEEK), poly(vinylidene fluoride) (PVdF), and urethane acrylate non-ionomer (UAN) were prepared for application in vanadium redox flow batteries (VRFBs). The key idea of this work is to combine the high proton-conducting property of sPEEK and low vanadium permeability of PVdF by introducing the amphiphilic UAN to the immiscible blend of sPEEK and PVdF, UAN makes the two polymers miscible. The blend membranes are characterized by water uptake, dimensional change, proton conductivity, vanadium ion permeability, and cross-sectional morphology. By introducing small amounts of UAN (1–2 wt%) to the sPEEK/PVdF blend, proton conductivity increases, while vanadium permeability shows a very small change, resulting in higher proton selectivity against vanadium ion transport. Therefore, VRFBs employing the sPEEK/PVdF/UAN blend membrane exhibit significant improvements in discharge capacity and energy efficiency (EE) in comparison with those based on the sPEEK/PVdF blend and even with a Nafion 212 membrane. These results show that UAN-assisted compatible sPEEK/PVdF/UAN blend membranes can be useful for enhancing the VRFB performance.

The Effect of Nano-Morphology Modification Using an Amphiphilic Polymer on the Proton Conductivity of Composite Membrane for a Polymer Membrane-Based Fuel Cell.

The effect of morphology modification using an amphiphilic polymer on the proton conductivity of composite membrane for a polymer membrane-based fuel cell was investigated. The proton conductivity of each composite membrane was analyzed by the electrochemical impedance spectroscopy (EIS). The morphological change was confirmed by scanning electron microscope (SEM). In the composite membrane, the proton conductive component was sulfonated poly(ether ether ketone) (sPEEK), while the nonconductive component was poly(vinylidenedifluoride) and the amphiphilic polymer as a compatibilizer was urethane acrylate non-ionomer (UAN). UAN as a compatibilizer improved the interfacial stability between sPEEK and PVdF polymers, even though two polymers were apparently immiscible. The homogeneous distribution of sPEEK and PVdF domains in the composite membrane was obtained with the introduction of UAN due to the amphiphilicity. Therefore, it was found that the proton conductivity of the composite membrane increased with the incorporation of UAN as a compatibilizer.

Synthesis of Magnetite/Amphiphilic Polymer Composite Nanoparticles as Potential Theragnostic Agents

This study describes the synthesis of magnetite/amphiphilic polymer composite nanoparticles that can be potentially used simultaneously for cancer diagnosis and therapy. The synthesis method was a one-shot process wherein magnetite nanoparticles were mixed with core-crosslinked amphiphilic polymer (CCAP) nanoparticles, prepared using a copolymer of a urethane acrylate nonionomer (UAN) and a urethane acrylate anionomer (UAA). The CCAP nanoparticles had a hydrophobic core and a hydrophilic exterior with both PEG segments and carboxylic acid groups, wherein the magnetite nanoparticles were coordinated and stabilized. According to DLS data, the ratio of UAN to UAA and the ratio of magnetite to polymer are keys to controlling the size and thus, the stability of the composite nanoparticles. The magnetic measurement indicated that the composite nanoparticles had superparamagnetic properties and high saturation magnetization. The preliminary magnetic resonance imaging showed that the particles produced an enhanced image even when their concentration was as low as 80 microg/ml.

The Compatibility of the Composite Membrane Based on Sulfonated Poly(Ether Ether Ketone) (sPEEK) / Poly(Vinylidenefluoride) (PVdF) / Urethane Acrylate Non-Ionomer (UAN) for a Unitized Regenerative Fuel Cell (URFC)

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Fabrication of inorganic/polymer nanocomposite membranes containing very high silica content via in situ surface grafting reaction and reactive dispersion of silica nanoparticles: Proton conduction, water uptake, and oxidative stability

AbstractIn this study, we present a new fabrication process for proton exchange membranes based on inorganic/organic nanocomposite using in situ surface grafting reaction and reactive dispersion of silica nanoparticles in the presence of reactive dispersant, urethane acrylate nonionomer (UAN). Through in situ surface grafting reaction of silica nanoparticles, urethane acrylates were chemically introduced on the surface of silica nanoparticles, which were dispersed in DMSO solutions containing UAN and sodium styrene sulfonate (NaSS). After urethane linkage and copolymerization of NaSS, UAN and urethane acrylate moieties of silica nanoparticles, the solutions were converted to silica nanoparticle‐dispersed proton exchange membranes where silica particles were chemically connected with organic polymer chains. 5.89–29.45 wt % of silica nanoparticles could be dispersed and incorporated in polymer membranes, which were confirmed by transmittance electron microscopy (TEM) measurement. On varying weight % of silica nanoparticles dispersed within the membranes, water uptake and oxidative stability of nanocomposite membranes were largely changed, but membranes showed almost the same proton conductivity (greater than 10−2 S cm−1). At 5.89 wt % of silica nanoparticles, nanocomposite membranes showed the lowest water uptake and excellent oxidative stability compared to the sulfonated polyimide membranes fabricated by us. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Self-assembled nanoplatform for targeted delivery of chemotherapy agents via affinity-regulated molecular interactions

Site-specific delivery of drugs while minimizing unwanted distribution has been one of the pursued goals in cancer therapy. In this endeavor, we have developed targeted polymeric nanoparticles called amphiphilic urethane acrylate nonionomer (UAN) for encapsulation of diverse water-insoluble drugs and diagnostic agents, as well as for simple and reproducible surface conjugation of targeting ligands. Using monoclonal antibodies or lymphocyte function-associated antigen-1 (LFA-1) I domain engineered for varying affinities to intercellular adhesion molecule (ICAM)-1, we were able to deliver UAN nanoparticles to human cancer cells with the efficiency dependent on the strength of the molecular interactions and the degree of ICAM-1 expression on cell surface. Compared to non-specific uptake of free drugs, targeted delivery of UAN nanoparticles carrying equal amount of drugs produced more potent cytotoxicity. Notably, without the targeting ligands attached, UAN nanoparticles were largely precluded from non-specific uptake by the cells, resulting in much lower toxicity. The versatility of our UAN nanoparticles in both payload encapsulation and presentation of targeting ligands may facilitate developing a robust platform for evaluating various combinations of cancer drugs and molecular interactions toward developing effective cancer therapy formulations.

Synthesis of CdS nanoparticles dispersed within solutions and polymer films using amphiphilic urethane acrylate chains

In this study, a new process for preparation of CdS/polymer nanocomposite films using a new amphiphilic oligomer chain (Urethane Acrylate Nonionomer: UAN) is presented. UAN chains have hydrophilic polyethylene oxide segments and polypropylene oxide-based hydrophobic segments as part of the same backbone. In addition, these chains also have reactive vinyl groups at their hydrophobic segments. For the preparation of CdS nano-colloid solutions, UAN chains acted as a stabilizer for CdS nanoparticles dispersed in a solvent. For the fabrication of CdS/polymer nanocomposite films, UAN chains in CdS nano-colloid solutions were polymerized through reactions between their vinyl groups, resulting in the formation of CdS nanoparticle dispersed films swollen by the solvent. The nature of the solvent used strongly influenced the size of the CdS nanoparticles, which was confirmed by UV absorption spectra, PL emission spectra and TEM images. Smaller sized CdS nanoparticles were formed in higher polar solvents such as DMAc and methanol, which can be explained by the higher solubility of UAN chains and the more effective dissociation and stabilization of cadmium salts and CdS nanoparticles by UAN chains in the polar solvent.

Conductive graphite/polyurethane composite films using amphiphilic reactive dispersant: Synthesis and characterization

Well-dispersed and conductive graphite (GP)/polymer composites films were fabricated using two different polymerizable amphiphilic dispersion agents namely urethane acrylate nonionomer (UAN) and polyethylene oxide (PEO) modified urethane acrylate (PMUA). Our GP/polymer composites were fabricated via in situ polymerization of unmodified GP and UAN or PMUA mixtures where UAN and PMUA acted not only as dispersion agents but also as macromonomer for the formation of the polymeric matrix. Dispersibility of GP in the polymeric matrix strongly depended on the type of amphiphilic dispersion agent, which was confirmed by SEM measurements. Fabricated composite films exhibited electrical conductivities of 10 −1 S/cm for UAN and 10 −2 S/cm for PMUA at 50 wt% of GP loading. From the thermogravimetric analysis, the introduction of graphite exhibits a beneficial effect on the thermal stability of poly(UAN) and poly(PMUA).

Synthesis of microphase‐separated poly(styrene‐co‐sodium styrene sulfonate) membranes using amphiphilic urethane acrylate nonionomers as an reactive compatibilizer

AbstractMicrophase‐separated poly(styrene‐co‐sodium styrene sulfonate) random copolymer (PSSU) membranes were fabricated through a new copolymerization process. Two immiscible monomers, styrene and sodium styrene sulfonate were dissolved in a single solvent and formed homogeneous solutions, which were directly converted to wall‐to‐wall membranes via radical copolymerization process with microphase separation. Since urethane acrylate nonionomer (UAN) chain has amphiphilicity as well as reactivity with vinyl monomers, UAN chain could act not only as compatibilizer for polystyrene and poly(sodium styrene sulfonate), but also as macrocrosslinker, which makes it possible for the formation of crosslinked copolymer of two immiscible polymers without macrophase separation. TEM image of the PSSU membranes showed that nanosized hydrophilic domains formed by hydrophilic/hydrophobic microphase separation were dispersed at hydrophobic matrix phase. PSSU membranes fabricated using UAN chain having longer chain length of polyethylene oxide showed bigger size of hydrophilic domains, which was also confirmed by TEM images. Fabricated PSSU membranes showed proton conductivity higher than 10−2 S/cm and methanol permeability lower than 10−7 cm2/s of Nafion® 117 membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008

Use of Polymer Nanoparticles as Functional Nano-Absorbents for Low-Molecular Weight Hydrophobic Pollutants

To use amphiphilic polymer nanoparticles as a new nano-absorbent for improving environmental process, urethane acrylate nonionomer (UAN) chain having hydrophobic polypropylene oxide-based segment and hydrophilic polyethylene oxide-based segment at the same backbone was synthesized and dispersed as nanoparticles at water phase without using a surfactant or dispersion agent. These UAN nanoparticles were converted to crosslinked amphiphilic polymer (CAP) nanoparticles through soap-free emulsion polymerization and suspension agent-free suspension polymerization process. Emulsion polymerization process exhibited higher conversion of polymerization compared to suspension polymerization process. CAP nanoparticles showed interfacial activity and solubilize hydrophobic pollutants (phenanthrene and toluene) like surfactant micelles. This result indicates possible application of CAP nanoparticles as nano-absorbent for improving efficiency of soil washing and micellar-enhanced ultrafiltration (MEUF) process.

Synthesis of microphase‐separated solvent‐free solid polymer electrolyte nanocomposite films using amphiphilic urethane acrylate precursors

AbstractA new solvent‐free solid polymer electrolyte (SPE) films could be fabricated through bulk copolymerization process of amphiphilic urethane acrylate nonionomer (UAN). Amphiphilic UAN chain having polypropylene oxide‐based hydrophobic segment and polyethylene oxide‐based hydrophilic segment can not only dissolve lithium salt by complex formation with lithium cations but also be copolymerized with various monomers to form microphase‐separated polymeric matrix. Unlike conventional SPE systems showing higher conductivity with polar polymers and polar solvents, our SPE films prepared by copolymerization of UAN and hydrophobic monomers exhibited relatively higher conductivity. Dissolving lithium salts in UAN/hydrophobic monomer mixtures caused hydrophilic/hydrophobic microphase separation, which was more favorable for ionic conduction of lithium ions, resulting in the higher ionic conductivity than the SPE films fabricated using UAN/hydrophobic monomer mixture. This microphase‐separated structure of SPE films could be also confirmed by transmission electron microscope (TEM) images. Ionic conductivity of our SPE films could be also improved by dispersing clay minerals within SPE films. Three types of clay having different surface properties were used to fabricate clay/SPE nanocomposite films. Ionic conductivity of nanocomposite films depended on dispersibliity of clay nanoparticles with a SPE film, which was confirmed by measuring X‐ray diffraction and TEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Preparation of organic–inorganic nanocomposite membrane using a reactive polymeric dispersant and compatibilizer: Proton and methanol transport with respect to nano-phase separated structure

A poly(styrene–NaSS–UAN) random copolymer (PSSU) consisting of a sulfonated monomer (NaSS) and a non-sulfonated monomer (styrene) was successfully fabricated through a new copolymerization scheme using a urethane acrylate non-ionomer (UAN) as a compatibilizer to reduce solubility differences and enhance the miscibility of each monomer. The TEM image of the PSSU membranes showed that the nano-phase separated structure was comprised of hydrophilic domains dispersed within the hydrophobic polymer matrix along with a peculiar biphasic swelling behavior. UAN also played a role as a dispersant to uniformly distribute the silica nanoparticles of different hydrophilicity and to obtain subsequent sulfonated polystyrene–silica nanocomposite membranes. In the PSSU nanocomposite membranes, the use of hydrophilic silica nanoparticles improved both the hydrophilicity and methanol barrier property of the membranes via a superior dispersion in the hydrophilic domains. Accordingly, it significantly contributed to an increase of the proton conductivity and a reduction of the methanol permeability. On the other hand, hydrophobic silica nanoparticles, which were mainly dispersed in the hydrophobic domains, compensated for excessive water swelling with an increase in the content of ionic groups. The membrane performances in the fully hydrated state could be conveniently controlled through the direct incorporation of nano-sized silica particles using UAN.

Synthesis of CdS Nanoparticles Dispersed Within Poly(urethane acrylate‐co‐styrene) Films Using an Amphiphilic Urethane Acrylate Nonionomer

AbstractSummary: CdS nanoparticles dispersed within poly(urethane acrylate‐co‐styrene) (PUCS) films were prepared using amphiphilic urethane acrylate nonionomer (UAN) precursor chains, which had a poly(propylene oxide)‐based hydrophobic segment and a hydrophilic poly(ethylene oxide) segment. CdS nanoparticles were first prepared and dispersed in UAN/styrene mixtures, and then these nano‐colloid solutions could be directly converted to CdS/PUCS nanocomposite films via radical bulk polymerization process. Formation of CdS nanoparticles was confirmed by UV absorption spectra, PL emission spectra and TEM images. The size of the CdS nanoparticles was varied from 10.2 to 14.5 nm, in correlation with the increase of amount of cadmium salt in the preparation composition, which was also confirmed by a red shift in the UV and PL emission spectra. In the course of the formation of the CdS nanoparticles within the UAN/styrene mixtures, the PEO segments of UAN are microphase‐separated from the hydrophobic segments of UAN and styrene to make a complex with the cadmium cations and stabilize the CdS nanoparticles. This was also confirmed by TEM images and DMA measurements.TEM micrograph of the polyurethane acrylate films containing CdS nanoparticles, prepared using a weight fraction of cadmium acetate of 0.125 wt.‐%.magnified imageTEM micrograph of the polyurethane acrylate films containing CdS nanoparticles, prepared using a weight fraction of cadmium acetate of 0.125 wt.‐%.

Synthesis of CdS nanoparticles dispersed within amphiphilic poly(urethane acrylate‐co‐styrene) films

AbstractCdS nanoparticles were prepared using amphiphilic urethane acrylate nonionomer (UAN) precursor chains having a poly(propylene oxide)‐based hydrophobic segment and a hydrophilic poly(ethylene oxide) segment. Cadmium salts were first dissolved in UAN/styrene solutions, and then the solutions were copolymerized to obtain poly(urethane acrylate‐co‐styrene) films containing dissolved cadmium salts. After reduction with H2S gas, freestanding films containing CdS nanoparticles were obtained. Transmission electron microscopy images of the films showed that 9.67‐nm CdS nanoparticles were dispersed within the poly(urethane acrylate‐co‐styrene) matrix. The formation of CdS nanoparticles was also confirmed with UV absorption spectra and photoluminescence emission spectra of the films. Transmission electron microscopy and dynamic mechanical analysis measurements confirmed that hydrophilic/hydrophobic microphase separation in UAN/styrene solutions occurred during the dissociation of the cadmium salts, and the microphase‐separated structures were locked in by crosslinking copolymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2357–2363, 2005

Synthesis of Poly(urethane acrylate‐co‐styrene) Films Containing Silver Nanoparticles by a Simultaneous Copolymerization/in situ Electron Transfer Reaction

AbstractSummary: A novel process for the synthesis of nanocomposite films containing silver nanoparticles is presented. Unlike conventional synthetic processes, silver nanoparticles and the polymer film constituting the nanocomposite film were synthesized simultaneously through an in situ electron transfer reaction and the copolymerization of styrene and amphiphilic urethane acrylate nonionomer (UAN), which contains hydrophobic poly(propylene oxide) segments and hydrophilic poly(ethylene oxide) segments along the same backbone. Silver nitrate crystals were first dissolved in a UAN/styrene solution through the formation of a complex between silver salts and the poly(ethylene oxide) chains of UAN, and then the transparent solutions obtained were directly converted to transparent free‐standing films containing silver nanoparticles by copolymerization and an electron transfer reaction by radicals. The amount of radical initiator strongly influenced the size and number of silver nanoparticles formed within the polymer films. The formation of silver nanoparticles was confirmed by transmission electron microscopy (TEM) and characteristic UV absorbance spectra. Hydrophobic/hydrophilic microphase separation in the UAN/styrene solution was also confirmed by TEM and mechanical property measurements.TEM image of poly(urethane‐co‐styrene) film containing silver nanoparticles.magnified imageTEM image of poly(urethane‐co‐styrene) film containing silver nanoparticles.

Comparison of amphiphilic polyurethane nanoparticles to nonionic surfactants for flushing phenanthrene from soil

Amphiphilic polyurethane (APU) nanoparticles were synthesized through crosslinking polymerization of nano-aggregates of urethane acrylate nonionomer (UAN). The efficiency of in situ extraction of sorbed phenanthrene from aquifer material was tested using soil columns and compared with that of surfactants such as Triton X-100, Brij 30, and Tween 80. The extraction efficiency of those washing materials strongly depended on their concentration, flow rate, and the degree of sorption within soil column. That is, the extraction efficiency increased with the decrease of flow rate and the degree of sorption and the increase of the concentration. Even though the surfactants are superior to APU nanoparticles at solubilizing phenanthrene, at the same flow rate (0.02 mL/min) and concentration (4000 mg/L), the effectiveness of in situ soil washing of APU nanoparticles was about two times higher than those of surfactants. This is because, at the lower flow rates, the degree of sorption of APU nanoparticles was lower than that of surfactants, owing to the chemically crosslinked nature of APU nanoparticles.

Synthesis of nanophase‐separated poly(urethane‐co‐acrylic acid) network films and their application for magnetic nanoparticle synthesis

AbstractPoly(urethane‐co‐acrylic acid) films were synthesized by the copolymerization of urethane acrylate nonionomer (UAN) and acrylic acid (AA) under different conditions. Poly(urethane‐co‐acrylic acid) films exhibited very different mechanical properties, attributed to the microstructural difference with the type of solvents used in the film preparation. The film synthesized using UAN/AA/water mixture had a relatively highly nanophase separated structure compared to that of the other films prepared using UAN/AA/dioxane mixture, resulting in higher mechanical property and glass‐transition temperature. The nanostructural differences could be also confirmed by atomic force microscopy measurements. Magnetic nanocomposite films synthesized based on UAN/AA/water and UAN/AA/dioxane mixtures showed different sizes of magnetic nanoparticles, attributed to the differences of size of hydrophilic nanodomains. The higher the degree of nanophase separation within poly(urethane‐co‐acrylic acid) films, the larger the size of hydrophilic nanodomains, resulting in formation of larger nanoparticles. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3549–3556, 2004

Effect of amphiphilic polyurethane nanoparticles on sorption–desorption of phenanthrene in aquifer material

Micelle-like amphiphilic nano-sized polyurethane (APU) nanoparticles were synthesized via chemical cross-linking reaction of nano-aggregates of urethane acrylate nonionomer (UAN) chain and were tested for extraction efficiency of sorbed phenanthrene from aquifer material. Even though the solubilizing performance and interfacial activity of APU nanoparticles were inferior to that of Triton X-100, in the low concentration region, APU nanoparticles could effectively reduce phenanthrene sorption on the aquifer material and extracted sorbed phenanthrene from the aquifer material, whereas Triton X-100 could not extract sorbed phenanthrene and rather increased phenanthrene sorption onto the aquifer materials. At higher concentrations, APU nanoparticles and Triton X-100 had almost the same soil washing effectiveness. This interesting result is mainly due to a lower degree of sorption of APU nanoparticles onto the aquifer material. The sorption of APU nanoparticles onto aquifer sand is largely hindered by their chemically cross-linked nature, resulting in better soil-washing performance of APU nanoparticles than Triton X-100.

Synthesis of Magnetic Nanocomposite Based on Amphiphilic Polyurethane Network Films

Magnetic nanocomposites, showing extremely small coercivity and hysteresis loop, were synthesized using amphiphilic polyurethane networks based on amphiphilic urethane acrylate nonionomer (UAN) precursor chains. Three kinds of UAN gel films were synthesized through UV-curing of UAN chains in the absence of a solvent, or crosslinking polymerization of UAN/water and UAN/DMAc mixtures. Even though these gel films were synthesized with the same UAN, these UAN gel films had very different microstructures depending on the preparation conditions; as a consequence, magnetic composites prepared with these crosslinked films exhibited very different size and morphology of magnetic nanoparticles. Atomic force microscopy and mechanical property measurements showed that UAN gel film (UANH) synthesized with UAN/water mixture had the highly microphase-separated structures whereas the gel films synthesized via UV-curing (UANV) or polymerization of UAN/DMAc mixture (UAND) had relatively homogeneous structures. The largest ellipsoidal particles were formed in UANH gel films and the smallest ellipsoidal particles and rod-shaped particles were made up in UANV gel and UAND gel film, which was confirmed by transmission electron microscopy. Transmission electron micrograph of magnetic composite film prepared with UANV.