WorldWideScience

Sample records for styrene acrylic acid

  1. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Science.gov (United States)

    2011-12-14

    ... AGENCY 40 CFR Part 180 Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption AGENCY...-propenoate and ethenylbenzene (CAS Reg. No. 25036-16-2); also known as butyl acrylate-methacrylic acid...-risk polymers are described in 40 CFR 723.250(d). Butyl acrylate-methacrylic acid-styrene polymer...

  2. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    OpenAIRE

    Keslarek Amauri José; Leite Carlos Alberto P; Galembeck Fernando

    2004-01-01

    Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM). Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the par...

  3. Acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.

    Science.gov (United States)

    Wang, C C; Lee, C M

    2006-01-01

    The aim of this study is to isolate the acrylic acid utilizing bacteria from the ABS resin manufactured wastewater treatment system. The bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. The aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. The results are: twenty strains were isolated from the ABS resin manufactured wastewater treatment system and twelve of them could utilize 600 mg/l acrylic acid for growth. Seven of twelve strains could tolerate the acrylonitrile and acrylamide toxicity, when the concentration was below 300 mg/l. Bacillus thuringiensis was one of the seven strains and the optimum growth temperature was 32 degrees C. Bacillus thuringiensis could utilize acrylic acid for growth, when the initial acrylic acid concentration was below 1,690.4 mg/l. Besides this, when the initial acrylic acid concentration was below 606.8 mg/l, the acrylic acid removal efficiency exceeded 96.3%. Bacillus thuringiensis could tolerate 295.7 mg/l acrylamide and 198.4 mg/l acrylonitrile toxicity but could not tolerate 297.3 mg/l epsilon-caprolactam.

  4. Surfactant and counter-ion distribution in styrene-butyl acrylate-acrylic acid dry latex submonolayers

    Directory of Open Access Journals (Sweden)

    Keslarek Amauri José

    2004-01-01

    Full Text Available Styrene-butyl acrylate-acrylic acid latex submonolayers prepared using a non-reactive phosphate surfactant together with a reactive sulfonate surfactant were examined in a transmission microscope using electron energy loss spectroscopy imaging (ESI-TEM. Phosphorus is nearly absent from the particles core but it is detected in a thick shell and in unusual, strongly scattering structures with a low carbon content, and largely made out of inorganic phosphate. P is also dispersed outside the particles, while S is uniformly distributed within then. The Na and N elemental maps show that the respective monovalent ions (Na+ and NH4+ have different distributions, in the latex: Na signal within the particles is stronger than in the background, while N is accumulated at the particle borders. The distributions of surfactant and counter-ions are thus different from some current assumptions, but they support recent results on the distribution of ionic constituents in latex films, by scanning electric potential microscopy.

  5. Preparation and Structural Analysis of Nano-Silver Loaded Poly(styrene-co-acrylic acid) Core-Shell Nanospheres with Defined Shape and Composition.

    Science.gov (United States)

    Zhang, Jin; Zhao, Xiaoyu; Wang, Yanfei; Zhu, Liang; Yang, Libin; Li, Gang; Sha, Zuoliang

    2017-08-23

    A systematic study for the preparation and structural analysis of poly(styrene- co -acrylic acid) composite nanospheres (PSA) and silver nanoparticles loaded poly(styrene- co -acrylic acid) composite nanospheres (nAg@PSA) is reported. Poly(styrene- co -acrylic acid) nanospheres were synthesized by soap-free emulsion polymerization of styrene (St) and acrylic acid (AA) in water. Ag nanoparticles (Ag-NPs) were well-dispersed on the surfaces of poly(styrene- co -acrylic acid) composite nanospheres by in situ chemical reduction of AgNO₃ using NaBH₄ as a reducing agent in water. The particle size of PSA nanospheres was uniform. The surfaces of PSA nanospheres were distributed by highly uniform half-sphere arrays. Those half-sphere protruded more with the increase of the feeding amount of AA or the feed ratios of AA and St. The carboxyl groups content of nanospheres was directly proportional to the nanosphere surface area. This relationship and X-ray photoelectron spectroscopy and transmission electron microscopy images of the PSA nanospheres indicate that the acrylic acid was mainly distributed on the surface of the polystyrene spheres with unnegligible thickness. The number of Ag-NPs depends on immobilized carboxyl groups on the surface of PSA, according to thermogravimetry, ultraviolet-visible, X-ray diffraction and transmission electron microscopy results.

  6. Electronically Stabilized Copoly(Styrene-Acrylic Acid Submicrocapsules Prepared by Miniemulsion Copolymerization

    Directory of Open Access Journals (Sweden)

    Minkwan Kim

    2017-07-01

    Full Text Available This work reports the preparation and characterization of poly(styrene-acrylic acid (St/AA submicrocapsules by using the miniemulsion copolymerization method. AA was introduced to miniemulsion polymerization of St to increase the zeta potential and the resulting electrostatic stability of St/AA submicrocapsules. Phytoncide oil was adopted as the core model material. Miniemulsion copolymerization of St and AA was conducted at a fixed monomer concentration (0.172 mol with a varying monomer feed ratio [AA]/[St] (0.2, 0.25, 0.33, 0.5, and 1.0. Concentrations of initiator (azobisisobutyronitrile; 1.0 × 10−3, 2.0 × 10−3, 3.0 × 10−3, and 4.0 × 10−3 mol/mol of monomer and surfactant (sodium dodecyl sulfate; 0.6 × 10−3, 1.0 × 10−3, and 1.4 × 10−3 mol were also controlled to optimize the miniemulsion copolymerization of St and AA. Dynamic light scattering and microscopic analyses confirmed the optimum condition of miniemulsion copolymerization of St and AA. Long-term colloidal stability of aqueous St/AA submicrocapsule suspension was evaluated by using TurbiscanTM Lab. In this work, the optimum condition for miniemulsion copolymerization of St and AA was determined ([AA]/[St] = 0.33; [SDS] = 1.0 × 10−3 mol; [AIBN] = 2.0 × 10−3 mol/mol of monomer. St/AA submicrocapsules prepared at the optimum condition (392.6 nm and −55.2 mV of mean particle size and zeta potential, respectively showed almost no variations in backscattering intensity (stable colloids without aggregation.

  7. Preparation, characterization, and antibacterial activity studies of silver-loaded poly(styrene-co-acrylic acid) nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Song, Cunfeng [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Chang, Ying; Cheng, Ling; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Zhang, Long; Zhong, Lina [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China)

    2014-03-01

    A simple method for preparing a new type of stable antibacterial agent was presented. Monodisperse poly(styrene-co-acrylic acid) (PSA) nanospheres, serving as matrices, were synthesized via soap-free emulsion polymerization. Field-emission scanning electron microscopy micrographs indicated that PSA nanospheres have interesting surface microstructures and well-controlled particle size distributions. Silver-loaded poly(styrene-co-acrylic acid) (PSA/Ag-NPs) nanocomposites were prepared in situ through interfacial reduction of silver nitrate with sodium borohydride, and further characterized by transmission electron microscopy and X-ray diffraction. Their effects on antibacterial activity including inhibition zone, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bactericidal kinetics were evaluated. In the tests, PSA/Ag-NPs nanocomposites showed excellent antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. These nanocomposites are considered to have potential application in antibacterial coatings on biomedical devices to reduce nosocomial infection rates. - Highlights: • A new type of antibacterial agent (PSA/Ag-NPs nanocomposites) was synthesized. • The antibacterial activity against S. aureus and E. coli was studied. • Inhibition zone, MIC, MBC, and bactericidal kinetics were evaluated. • PSA/Ag-NPs nanocomposites showed excellent antibacterial activity.

  8. Synthesis of hollow silver spheres using poly-(styrene-methyl acrylic acid) as templates in the presence of sodium polyacrylate

    Science.gov (United States)

    Wang, Aili; Yin, Hengbo; Ge, Chen; Ren, Min; Liu, Yumin; Jiang, Tingshun

    2010-02-01

    Hollow silver spheres were successfully prepared by reducing AgNO 3 with ascorbic acid and using negatively charged poly-(styrene-methyl acrylic acid) (PSA) spheres as templates in the presence of sodium polyacrylate as a stabilizer. Firstly, silver cations adsorbed on the surface of PSA spheres via electrostatic attraction between the carboxyl groups and silver cations were reduced in situ by ascorbic acid. The silver nanoparticles deposited on the surface of PSA spheres served as seeds for the further growth of silver shells. After that, extra amount of AgNO 3 and ascorbic acid solutions were added to form PSA/Ag composites with thick silver shells. In order to obtain compact silver shells, the as-prepared PSA/Ag composites were heated at 150 °C for 3 h. Then hollow silver spheres were prepared by dissolving PSA templates with tetrahydrofuran.

  9. Preparation and drug-loading properties of Fe{sub 3}O{sub 4}/Poly(styrene-co-acrylic acid) magnetic polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wensheng [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China); Shen, Yuhua, E-mail: s_yuhua@163.com [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Xie, Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Zhang, Weiqiang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Coordination Chemistry Institute, School of Chemistry and Chemical Engineering and Life Science, Chaohu University, Chaohu 238000 (China)

    2013-11-15

    Fe{sub 3}O{sub 4}/poly(styrene-co-acrylic acid) magnetic polymer nanocomposites were synthesized by the dispersion polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe{sub 3}O{sub 4} nanoparticles modified with oleic acid as core, and poly(styrene-co-acrylic acid) as shell. Drug-loading properties of magnetic polymer nanocomposites with curcumin as a model drug were also studied. The results indicated that magnetic polymer nanocomposites with monodisperse were obtained, the particle size distribution was 50–120 nm, and the average size was about 100 nm. The contents of poly(styrene-co-acrylic acid) and Fe{sub 3}O{sub 4} nanoparticles in magnetic polymer nanocomposites were 74% and 24.7%, respectively. The drug-loading capacity and entrapment efficiency were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer nanocomposites at 300 K was 20.2 emu/g without coercivity and remanence. The as-prepared magnetic polymer nanocomposites have not only lots of functional carboxyl groups but also stronger magnetic response, which might have potential applications in drug carrier and targeted drug release.

  10. Synthesis of Poly(styrene-acrylates-acrylic acid Microspheres and Their Chemical Composition towards Colloidal Crystal Films

    Directory of Open Access Journals (Sweden)

    Luis A. Ríos-Osuna

    2016-01-01

    Full Text Available In this paper, polystyrene colloidal microspheres have been prepared using hexyl acrylate (HA, ethylhexyl acrylate (EHA, isooctyl acrylate (IOA, butyl acrylate (BA, or isobutyl acrylate (IBA as comonomers. Microspheres with diameters from 212 to 332 nm and with a polystyrene content of 65–78% were prepared. The particles prepared in this work do not present the typical core-shell structure; as a consequence, DSC analysis showed that the microspheres exhibited only one Tg. TEM images show that the particles with comonomer content below ~30% were spherical and regular. Microspheres containing comonomer between 21 to 25% produced the less brittle films showing very iridescent colors. The films prepared from microspheres containing hexyl, ethylhexyl, and isooctyl acrylate as comonomers are firmly attached to the substrate due to their adhesive properties. The large decrease of the fragility observed in these films makes them much more attractive materials in sensing applications.

  11. Simultaneous production of biobased styrene and acrylates using ethenolysis

    NARCIS (Netherlands)

    Spekreijse, J.; Notre, le J.E.L.; Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2012-01-01

    Phenylalanine (1), which could be potentially obtained from biofuel waste streams, is a precursor of cinnamic acid (2) that can be converted into two bulk chemicals, styrene (3) and acrylic acid (4), via an atom efficient pathway. With 5 mol% of Hoveyda–Grubbs 2nd generation catalyst, 1 bar of

  12. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-01-30

    ... AGENCY 40 CFR Part 180 Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption AGENCY: Environmental...; also known as styrene-2-ethylhexyl acrylate copolymer when used as an inert ingredient in a pesticide...-risk polymers are described in 40 CFR 723.250(d). Styrene-2-ethylhexyl acrylate copolymer conforms to...

  13. Comparative study of the self-aggregation of rhodamine 6G in the presence of poly(sodium 4-styrenesulfonate), poly(N-phenylmaleimide-co-acrylic acid), poly(styrene-alt-maleic acid), and poly(sodium acrylate).

    Science.gov (United States)

    Moreno-Villoslada, Ignacio; Fuenzalida, Juan Pablo; Tripailaf, Gustavo; Araya-Hermosilla, Rodrigo; Pizarro, Guadalupe del C; Marambio, Oscar Guillermo; Nishide, Hiroyuki

    2010-09-23

    The interaction between rhodamine 6G and different polyelectrolytes is analyzed. Structural aspects differentiate these polyelectrolytes, such as the presence of aromatic groups and the number and localization of their respective charges, which may be directly attached to the aromatic groups or to the polymeric main chain. In the case of poly(sodium acrylate), which does not bear aromatic groups, the polyelectrolyte induces cooperative self-stacking between the dyes which is highly sensitive to the ionic strength, due to the predominance of long-range electrostatic interactions between the polymer and the dye. In the case of poly(sodium 4-styrenesulfonate), whose charge is directly attached to the aromatic groups, a high dispersant ability of the dyes is found and the interaction is less dependent on the ionic strength, due to the predominance of short-range aromatic-aromatic interactions between the dye and the polymer. Among the two polyelectrolytes studied for which the polymeric charge is directly attached to the main chain, and separated from the aromatic group, poly(styrene-alt-maleic acid) shows a lower dependence of the interaction on the ionic strength than poly(N-phenylmaleimide-co-acrylic acid) at a comonomer composition of 1:2, due to a higher linear aromatic density and a lower linear charge density, indicating the importance of hydrophobic forces. Both copolymers exhibit a high ability to induce cooperative self-aggregation of the dye.

  14. LF-NMR study of effect the octadecylamine addition in the copolymerization process between acrylic acid and styrene monomers; Estudo por RMN de baixo campo do efeito da adicao de octadecilamina na copolimerizacao dos monomeros de acido acrilico e estireno

    Energy Technology Data Exchange (ETDEWEB)

    Pedroza, Oscar J.O.; Tavares, Maria I.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano]. E-mail: oscarjop@ima.ufrj.br, mibt@ima.ufrj.br

    2005-07-01

    The copolymer content at least two monomer units that are the repetitive unities in the polymeric chains. The use of Low Field Nuclear Magnetic Resonance (LF-NMR), MARAN ultra 23, was applied to measure the proton spin-lattice relaxation time values. The process of copolymerization between the acrylic acid (A) and the styrene (S) monomers was studied with the addition of the octadecylamine (D) in the acrylic acid monomer. These materials were submitted at reflux by 24 hours. After this process the polymerization was carried out at room temperature. The values of the relaxation parameter are showed in Table 1. The co polymerizations between acrylic acid and styrene monomers were influenced by the octadecylamine addition. The results showed that an increase in the amine concentration promotes flexibility in the final material. This can be explained in terms of chains size after amine addition, which promotes an increasing in the free space among the polymer chains. (author)

  15. Systematic investigation of the synthesis of core-shell poly(styrene-co-acrylic acid) colloids with varying shell thickness and core diameter

    DEFF Research Database (Denmark)

    Hinge, Mogens; Keiding, Kristian

    2006-01-01

    by titration, dynamic light scattering (DLS), scanning electron microscopy (SEM) and transition electron microscopy (TEM).   The acrylic acid was fully incorporated into the poly(ST-co-AA) colloids in blocks and/or clusters and the purified poly(ST-co-AA) colloids swelled when pH was changed from low (4......) to high (10). There was a linear correlation between the incorporated amount of acrylic acid and the swelling for the purified poly(ST-co-AA) colloids. The swelling is thus ascribed to ionization of poly(acrylic acid). Samples were taken during synthesis and the fractional conversion and size...

  16. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane...

  17. Electrokinetic characterization of poly(acrylic acid) and poly(ethylene oxide) brushes in aqueous electrolyte solutions

    NARCIS (Netherlands)

    Zimmermann, R.; Norde, W.; Cohen Stuart, M.A.; Werner, C.

    2005-01-01

    Surfaces carrying hydrophilic polymer brushes were prepared from poly(styrene)-poly(acrylic acid) and poly(styrene)-poly(ethylene oxide) diblock copolymers, respectively, using a Langmuir-Blodgett technique and employing poly(styrene)-coated planar glass as substrates. The electrical properties of

  18. The electrospinning of the copolymer of styrene and butyl acrylate for its application as oil absorbent.

    Science.gov (United States)

    Xu, Naiku; Cao, Jipeng; Lu, Yuyao

    2016-01-01

    Electrospun polystyrene materials have been employed as oil absorbents, but they have visible drawbacks such as poor strength at low temperature and unreliable integrity because of brittleness and insufficient cohesive force among fibers. Butyl acrylate can polymerize into flexible chains, and its polymer can be used as elastomer and adhesive material. Thereby it is possible to obtain the material that has better performance in comparison with electrospun polystyrene material through the electrospinning of the copolymer of styrene and butyl acrylate. In this work, a polymer was synthesized through suspension polymerization by using styrene and butyl acrylate as comonomers. The synthesis of the copolymer of styrene and butyl acrylate was verified through dissolution and hydrolysis experimental data; as well through nuclear magnetic resonance spectrometry. The viscous flow activation energy of the solution consisting of copolymer and N, N-dimethylformamide was determined via viscosity method and then adopted to establish the entanglement characteristics of butyl acrylate's chain segments. Finally, in order to electrospin the copolymer solution into fibrous membrane, the effects of monomer feed ratio and spinning parameters were investigated. The prepared fibrous membrane was found to have a potential use as oil absorbent.

  19. High Solid Contents Copoly (Styrene/Butyl Acrylate)-Cloisite 30B Nanocomposites

    OpenAIRE

    M. Mirzataheri

    2013-01-01

    Higher solid contents (20 % and 40 %) nanocomposites of poly (styrene-co-butyl acrylate) including higher content of Cloisite 30B (7 wt% and 10 wt %) were prepared via miniemulsion polymerization. Stability of the final latexes proved outstanding combination of polymerization procedure and surfactants. Morphological studies revealed by TEM, SAX and XRD showed three structures of core-shell, armored and individual dispersion of clay layers within the polymer particles. The effect of Cloisite 3...

  20. High Solid Contents Copoly (Styrene/Butyl Acrylate-Cloisite 30B Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mirzataheri

    2013-03-01

    Full Text Available Higher solid contents (20 % and 40 % nanocomposites of poly (styrene-co-butyl acrylate including higher content of Cloisite 30B (7 wt% and 10 wt % were prepared via miniemulsion polymerization. Stability of the final latexes proved outstanding combination of polymerization procedure and surfactants. Morphological studies revealed by TEM, SAX and XRD showed three structures of core-shell, armored and individual dispersion of clay layers within the polymer particles. The effect of Cloisite 30B content on the barrier properties presents excellent and wide use of these films for packaging and nanocoatings industries.

  1. Thermodynamics of coil-hyperbranched poly(styrene-b-acrylated epoxidized soybean oil) block copolymers

    Science.gov (United States)

    Lin, Fang-Yi; Hohmann, Austin; Hernández, Nacú; Cochran, Eric

    Here we present the phase behavior of a new type of coil-hyperbranched diblock copolymer: poly(styrene- b-acrylated epoxidized soybean oil), or PS-PAESO. PS-PAESO is an example of a biorenewable thermoplastic elastomer (bio-TPE). To date, we have shown that bio-TPEs can be economical commercial substitutes for their petrochemically derived analogues--such as poly(styrene- b-butadiene- b-styrene) (SBS)--in a range of applications including pressure sensitive adhesives and bitumen modification. From a polymer physics perspective, PS-PAESO is an interesting material in that it couples a linear coil-like block with a highly branched block. Thus in contrast to the past five decades of studies on linear AB diblock copolymers, coil-hyperbranched block copolymers are relatively unknown to the community and can be expected to deviate substantially from the standard ``universal'' phase behavior in the AB systems. To explore these new materials, we have constructed a library of PS-PAESO materials spanning a range of molecular weight and composition values. The phase transition behavior and the morphology information will be interpreted by isochronal temperature scanning in dynamic shear rheology, small angle X-ray scattering and the corresponding transmission electron microscopy.

  2. -Styrene)

    KAUST Repository

    Sutisna, Burhannudin

    2017-10-04

    Membranes are prepared by self-assembly and casting of 5 and 13 wt% poly(styrene-b-butadiene-b-styrene) (PS-b-PB-b-PS) copolymers solutions in different solvents, followed by immersion in water or ethanol. By controlling the solution-casting gap, porous films of 50 and 1 µm thickness are obtained. A gradient of increasing pore size is generated as the distance from the surface increased. An ordered porous surface layer with continuous nanochannels can be observed. Its formation is investigated, by using time-resolved grazing incident small angle X-ray scattering, electron microscopy, and rheology, suggesting a strong effect of the air-solution interface on the morphology formation. The thin PS-b-PB-b-PS ordered films are modified, by promoting the photolytic addition of thioglycolic acid to the polybutadiene groups, adding chemical functionality and specific transport characteristics on the preformed nanochannels, without sacrificing the membrane morphology. Photomodification increases fivefold the water permeance to around 2 L m(-2) h(-1) bar(-1) , compared to that of the unmodified one. A rejection of 74% is measured for methyl orange in water. The membranes fabrication with tailored nanochannels and chemical functionalities can be demonstrated using relatively lower cost block copolymers. Casting on porous polyacrylonitrile supports makes the membranes even more scalable and competitive in large scale.

  3. Stereoregularity evolution of isobornyl acrylate and styrene copolymers by 2D NMR spectroscopy

    Science.gov (United States)

    Khandelwal, Deepika; Hooda, Sunita; Brar, A. S.; Shankar, Ravi

    2013-10-01

    Isobornyl acrylate/styrene (B/S) copolymers of different compositions have been prepared by Atom Transfer Radical Polymerization (ATRP) using methyl-2-bromopropionate as an initiator and PMDETA/CuBr as catalyst under nitrogen atmosphere at 60 °C. Copolymer compositions calculated from 1H NMR spectra are used to determine the reactivity ratios of monomers. Linear Kelen-Tudos (KT) and non-linear error in variable methods (EVM) have been employed for determination of monomer reactivity ratios in copolymers. The reactivity ratios obtained from KT and EVM are found to be rB = 0.41 ± 0.08, rS = 0.92 ± 0.13 and rB = 0.41 and rS = 0.93 respectively. These copolymers have been analyzed for their stereochemical structure using various 1D (1H, 13C{1H}, DEPT) and 2D (HSQC, TOCSY, NOESY, HMBC) NMR techniques. 2D HSQC and TOCSY NMR experiments are employed to resolve the highly overlapped and complex 1H and 13C{1H} NMR spectra of the copolymers. Spatial coupling of different types of protons are resolved by 2D NOESY NMR spectra. The configurational and compositional sequences of β-methylene carbons are assigned upto tetrad level whereas methine carbon is assigned as triad level of compositional sequences. The quaternary carbon of styrene and carbonyl carbon of isobornyl acrylate have been assigned as triad level of compositional sequences and are further confirmed by 2D HMBC NMR spectra.

  4. Star polymers by ATRP of styrene and acrylates employing multifunctional initiators

    DEFF Research Database (Denmark)

    Jankova, Katja Atanassova; Bednarek, Melania; Hvilsted, Søren

    2005-01-01

    Multifunctional initiators for atom transfer radical polymerization (ATRP) are prepared by converting ditrimethylolpropane with four hydroxyl groups, dipentaerythritol with six hydroxyl groups, and poly(3-ethyl-3-hydroxymethyl-oxetane) with similar to 11 hydroxyl groups to the corresponding 2......-bromoisobutyrates or 2-bromopropionates as obtained by reaction with acid bromides. Star polystyrene (PS) is produced by using these macroinitiators and neat styrene in a controlled manner by ATRP at 110 degrees C, employing the catalytic system CuBr and bipyridine. M. up to 51,000 associated with narrow molecular...

  5. A novel self-embrittling strippable coating for radioactive decontamination based on silicone modified styrene-acrylic emulsion

    Science.gov (United States)

    Wang, Jing; Wang, Jianhui; Zheng, Li; Li, Jian; Cui, Can; Lv, Linmei

    2017-03-01

    Silicone modified styrene-acrylic emulsion and butyl acrylate were used as a main film-forming agent and an additive respectively to synthesize a self-embrittling strippable coating. The doping mass-ratio of butyl acrylate was adjusted at 0, 5%, 10%, 15%, 20%, and the results indicated the optimized doping ratio was 10%. Ca(OH)2 was used to promote the coating film self-embrittling at a moderate doping mass-ratio of 20%. The synthesized coating’s coefficients of α and β decontamination on concrete, marble, glass and stainless steel surfaces were both greater than 85%, which indicated the synthesized coating is a promising cleaner for radioactive decontamination.

  6. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  7. 21 CFR 573.120 - Acrylamide-acrylic acid resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Acrylamide-acrylic acid resin. 573.120 Section 573.120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Additive Listing § 573.120 Acrylamide-acrylic acid resin. Acrylamide-acrylic acid resin...

  8. 21 CFR 176.110 - Acrylamide-acrylic acid resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylamide-acrylic acid resins. 176.110 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.110 Acrylamide-acrylic acid resins. Acrylamide-acrylic acid resins may be safely used as components of articles intended for use in producing...

  9. Copper mediated controlled radical copolymerization of styrene and2-ethylhexyl acrylate and determination of their reactivity ratios.

    Directory of Open Access Journals (Sweden)

    Bishnu Prasad Koiry

    2014-10-01

    Full Text Available Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA and styrene using copper bromide (CuBr as catalyst in combination with N,N,N’,N,N- pentamethyldiethylenetriamine (PMDETA as ligand and 1-phenylethyl bromide (PEBr as initiator. Linear kinetic plot and linear increase in molecular weights versus conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using 1H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2 were determined using the Finemann-Ross (FR, inverted Finemann-Ross (FR and Kelen-Tudos (KT methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

  10. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    Science.gov (United States)

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  11. IMPROVING OF RECLAIMED ASPHALT PAVEMENTS USING STYRENE-BUTYL ACRYLATE POLYMER

    OpenAIRE

    Abdelzaher E. A. Mostafa; Nasser, A M

    2017-01-01

    According to the most recent surveys, the European area produced 265 mil tons of asphalt for road applications in 2014, while the amount of available Reclaimed Asphalt Pavement (RAP) was more than 50 mil tons. The use of RAP in new blended mixes reduces the need of neat bitumen, making RAP recycling economically attractive. This study investigates the potential use of styrene-bacrylate polymer and extracted Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) with different percentages b...

  12. Investigation of Acrylic Acid at High Pressure using Neutron Diffraction

    DEFF Research Database (Denmark)

    Johnston, Blair F.; Marshall, William G.; Parsons, Simon

    2014-01-01

    This article details the exploration of perdeuterated acrylic acid at high pressure using neutron diffraction. The structural changes that occur in acrylic acid-d4 are followed via diffraction and rationalised using the Pixel method. Acrylic acid undergoes a reconstructive phase transition to a new...... phase at ~0.8 GPa and remains molecular to 7.2 GPa before polymerising on decompression to ambient pressure. The resulting product is analysed via Raman, FT-IR spectroscopy and Differential Scanning Calorimetry and found to possess a different molecular structure compared with polymers produced via...

  13. Preparation and self-sterilizing properties of Ag@TiO2-styrene-acrylic complex coatings.

    Science.gov (United States)

    Zhou, Xiang-dong; Chen, Feng; Yang, Jin-tao; Yan, Xiao-hui; Zhong, Ming-qiang

    2013-04-01

    In this study, we report a simple and cost-effective method for self-sterilized complex coatings obtained by Ag@TiO2 particle incorporation into styrene-acrylic latex. The Ag@TiO2 particles were prepared via a coupling agent modification process. The composite latices characterized by transmission electron microscopy (TEM) study were highly homogeneous at the nanometric scale, and the Ag@TiO2 particles were well dispersed and exhibited an intimate contact between both the organic and inorganic components. The Ag@TiO2 nanoparticles significantly enhanced the absorption in the visible region and engendered a good heat-insulating effect of the complex coatings. Moreover, the Ag@TiO2 nanoparticle incorporation into this polymer matrix renders self-sterilized nanocomposite materials upon light excitation, which are tested against Escherichia coli and Staphylococcus aureus. The complex coatings display an impressive performance in the killing of all micro-organisms with a maximum for a Ag@TiO2 loading concentration of 2-5 wt.%. The weathering endurance of the complex coating was also measured. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Formaldehyde, condensated... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

  15. Synthesis and characterization of polycaprolactone/acrylic acid ...

    Indian Academy of Sciences (India)

    ... of polycaprolactone/acrylic acid (PCL/AA) hydrogel for controlled drug delivery ... by measuring diffusion coefficient () and equilibrium water content (EWC). Network formation, morphology and crystallinity of PCL/AA hydrogels were ...

  16. A facile one-pot synthesis of acrylated hyaluronic acid.

    Science.gov (United States)

    A, Sigen; Xu, Qian; McMichael, Peter; Gao, Yongsheng; Li, Xiaolin; Wang, Xi; Greiser, Udo; Zhou, Dezhong; Wang, Wenxin

    2018-01-25

    The synthesis of acrylated hyaluronic acid (HA-A) normally requires 2 to 3 steps of modification, needs laborious purification and also increases the risks of HA degradation. Here, we report that the conjugation of acrylate groups to hyaluronic acid can be successfully achieved via a new facile one-pot approach. Two types of new HA-A hydrogels (via chemical or UV crosslinking) were developed and applied for 3D cell encapsulation.

  17. ABS polymer electroless plating through a one-step poly(acrylic acid) covalent grafting.

    Science.gov (United States)

    Garcia, Alexandre; Berthelot, Thomas; Viel, Pascal; Mesnage, Alice; Jégou, Pascale; Nekelson, Fabien; Roussel, Sébastien; Palacin, Serge

    2010-04-01

    A new, efficient, palladium- and chromium-free process for the electroless plating of acrylonitrile-butadiene-styrene (ABS) polymers has been developed. The process is based on the ion-exchange properties of poly(acrylic acid) (PAA) chemically grafted onto ABS via a simple and one-step method that prevents using classical surface conditioning. Hence, ABS electroless plating can be obtained in three steps, namely: (i) the grafting of PAA onto ABS, (ii) the copper Cu(0) seeding of the ABS surface, and (iii) the nickel or copper metallization using commercial-like electroless plating bath. IR, XPS, and SEM were used to characterize each step of the process, and the Cu loading was quantified by atomic absorption spectroscopy. This process successfully compares with the commercial one based on chromic acid etching and palladium-based seed layer, because the final metallic layer showed excellent adhesion with the ABS substrate.

  18. Ionizing radiation-induced copolymerization of 2-ethylhexyl acrylate and acrylic acid and ionomer formation

    Science.gov (United States)

    Weaver, Alia

    The ionizing radiation-induced polymerization of acrylate esters is a technique employed for the curing of such materials for a variety of adhesive, coating, ink, and lithographic applications. The work presented in this dissertation involves the synthesis of a copolymer composed of 2-ethylhexyl acrylate (2-EHA) and acrylic acid (AA) using pulsed electron beam and gamma irradiation. The structure and synthesis kinetics of this copolymer were investigated by 1H nuclear magnetic resonance (NMR), electron pulse radiolysis with kinetic spectroscopic detection (PR-KSD), and Fourier transform infrared spectroscopy (FTIR). The effects of total dose, dose rate, and acrylic acid content on the polymerization reaction were studied. The conversion of 2-EHA monomer into polymer at a given total dose was found to be enhanced at lower dose rates and higher concentrations of acrylic acid. The pulse radiolysis investigation of the polymerization of 2-EHA and AA was performed through studies of four different types of systems: (i) neat 2-EHA, (ii) 2-EHA/methanol (MeOH) solutions, (iii) mixtures of 2-EHA and AA, and (iv) 2-EHA/AA/MeOH solutions. The build-up of carbon-centered neutral 2-EHA free radicals in neat 2-EHA was found to obey a second order rate law with a rate coefficient of ((7 +/- 3) x 108)epsilon EHA·, whereas in 2-EHA/AA mixtures it was found to obey a pseudo-first order rate law with a rate coefficient of (1.5 +/- 0.3) x 10 10 mol-1 dm3 s-1. This phenomenon is suggested to originate in the increased H+ ion concentration in the presence of acrylic acid, which leads to a faster neutralization step of 2-EHA radical anions as they are transformed into neutral free radicals during the initiation step of the reaction. An investigation of the formation of ion-containing copolymers (known as ionomers) was performed using the radiation-synthesized poly(2-EHA-co-AA) and iron cations. Verification of successful incorporation of iron into the copolymer was identified by an

  19. Analysis of Mechanical and Thermogravimetric Properties of Composite Materials Based on PVA/MWCNT and Styrene-Acrylic Copolymer/MWCNT

    Science.gov (United States)

    Volynets, N. I.; Poddubskaya, O. G.; Demidenko, M. I.; Lyubimov, A. G.; Kuzhir, P. P.; Suslyaev, V. I.; Pletnev, M. A.; Zicans, Janis

    2017-08-01

    Mechanical and thermogravimetric properties of polymer composite materials with various concentrations of multiwalled carbon nanotubes effectively shielding radiation in the radio frequency (20 Hz - 1 MHz) and microwave (26-36 GHz) frequency ranges are studied. As a matrix, widely available polymeric materials, such as polyvinyl acetate and styrene-acrylate, were used in the form of dispersions. From the analysis of the obtained experimental data, it was shown that the introduction of carbon nanotubes into the polymer matrix makes it possible to increase mechanical properties and thermal stability of composite materials.

  20. Decarboxylation-based traceless linking with aroyl acrylic acids

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    beta-Keto carboxylic acids are known to decarboxylate readily. In our pursuit to synthesize beta-indolinyl propiophenones, we have exploited this chemistry as a mean of establishing a traceless handle. 2-Aroyl acrylic acids have been esterified to a trityl resin, after which Michael-type addition...

  1. Acrylic-acid-functionalized PolyHIPE scaffolds for use in 3D cell culture.

    Science.gov (United States)

    Hayward, Adam S; Sano, Naoko; Przyborski, Stefan A; Cameron, Neil R

    2013-12-01

    This study describes the development of a functional porous polymer for use as a scaffold to support 3D hepatocyte culture. A high internal phase emulsion (HIPE) is prepared containing the monomers styrene (STY), divinylbenzene (DVB), and 2-ethylhexyl acrylate (EHA) in the external oil phase and the monomer acrylic acid (Aa) in the internal aqueous phase. Upon thermal polymerization with azobisisobutyronitrile (AIBN), the resulting porous polymer (polyHIPE) is found to have an open-cell morphology and a porosity of 89%, both suitable characteristics for 3D cell scaffold applications. X-ray photo-electron spectroscopy reveals that the polyHIPE surface contained 7.5% carboxylic acid functionality, providing a useful substrate for subsequent surface modifications and bio-conjugations. Initial bio-compatibility assessments with human hepatocytes show that the acid functionality does not have any detrimental effect on cell adhesion. It is therefore believed that this material can be a useful precursor scaffold towards 3D substrates that offer tailored surface functionality for enhanced cell adhesion. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    NARCIS (Netherlands)

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  3. Effect of acrylic acid on the properties of polyvinylpyrrolidone ...

    African Journals Online (AJOL)

    Hydrogels based on polyvinylpyrrolidone (PVP) networks grafted with acrylic acid (AAc) was prepared by using γ-rays from a Co-60 source at room temperature. The parameters like effect of radiation dose and concentration of AAc were studied. The properties such as gel content, swelling behavior and thermal stability ...

  4. 40 CFR 721.9640 - Salt of an acrylic acid - acrylamide terpolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Salt of an acrylic acid - acrylamide... Specific Chemical Substances § 721.9640 Salt of an acrylic acid - acrylamide terpolymer (generic). (a... generically as salt of an acrylic acid - acrylamide terpolymer (PMN P-99-817) is subject to reporting under...

  5. Use of Acrylic Acid Sodium Acrylate Polymer to Maintain Cocoa Seed Viability

    Directory of Open Access Journals (Sweden)

    Pudji Rahardjo

    2010-08-01

    Full Text Available The main problem of cocoa seed storage is moisture content of the seeds because cocoa seeds will germinate if cocoa seeds moisture content is high. The objective of this research is to maintain the cocoa seeds viability in storage using acrylic acid sodium acrylate polymer (AASAP. The function of AASAP is to absorb humidity in storage due to their ability to retain water and to prevent water loss. The experiment was conducted in a laboratory of Indonesian Coffee and Cocoa Research Institute and in Kaliwining Experimental Garden. This experiment was arranged by factorial randomized complete design, in wich AASAP dosages 0%; 0.1% (0.1 g/100 seeds; 0.2% (0.2 g/100 seeds, 0.3% (0.3 g/100 seeds, 0,4% (0,4g/100 seeds, combined with seeds storage period 1, 2, 3 and 4 weeks. The experiment used 3 replications and each repli cation used 100 seeds. Parameter of observation consisted of percentage of seeds germinated in storage, percentage of seeds infected by fungi in storage, seeds moisture content, percentage of seeds germination after storage, and early growth of cocoa seedlings. The results of the experiment showed that AASAP application with some dosages cocoa seeds storage cause to germinate in storage during 2 weeks. AASAP application with some dosages in cocoa seeds storage for 2 weeks would not result in infection by fungi and did not significantly affect seed germination after storage for 1, 2 and 4 weeks, and percentage of germination of cocoa seed after storage for 3 weeks decreased with increase dosage of AASAP. Higher dosage of AASAP would reduce early growth of cocoa seedling. Key words : Theobroma cacao, seed, acrylic acid sodium acrylate, seed storage, viabilty.

  6. In Situ Investigation of the Adsorption of Styrene Phosphonic Acid on Cassiterite (110) Surface by Molecular Modeling

    National Research Council Canada - National Science Library

    Guichen Gong; Yuexin Han; Jie Liu; Yimin Zhu; Yanfeng Li; Shuai Yuan

    2017-01-01

    The flotation, adsorption and bonding mechanisms of styrene phosphonic acid (SPA) to cassiterite were studied using microflotation tests, zeta potential measurements, solution chemistry analysis and density functional theory...

  7. Synthesis and Characterization of Poly (styrene-co-butyl acrylate)/Silica Aerogel Nanocomposites by in situ AGET ATRP: Investigating Thermal Properties

    Science.gov (United States)

    Khezri, Khezrollah; Fazli, Yousef

    2017-10-01

    Hydrophilic silica aerogel nanoparticles surface was modified with hexamethyldisilazane. Then, the resultant modified nanoparticles were used in random copolymerization of styrene and butyl acrylate via activators generated by electron transfer for atom transfer radical polymerization. Conversion and molecular weight determinations were performed using gas and size exclusion chromatography respectively. Addition of modified nanoparticles by 3 wt% results in a decrease of conversion from 68 to 46 %. Molecular weight of copolymer chains decreases from 12,500 to 7,500 g.mol-1 by addition of 3 wt% modified nanoparticles; however, PDI values increase from 1.1 to 1.4. Proton nuclear magnetic resonance spectroscopy results indicate that the molar ratio of each monomer in the copolymer chains is approximately similar to the initial selected mole ratio of them. Increasing thermal stability of the nanocomposites is demonstrated by thermal gravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing modified silica aerogel nanoparticles.

  8. Effect of porosity and environment on the mechanical behavior of acrylic bone cement modified with acrylonitrile-butadiene-styrene particles: I. Fracture toughness.

    Science.gov (United States)

    Vila, M M; Ginebra, M P; Gil, F J; Planell, J A

    1999-01-01

    The elastomeric copolymer acrylonitrile-butadiene-styrene (ABS) was added to a conventional acrylic bone cement matrix. The results obtained show that although strength and stiffness decreased with an increasing second phase volume fraction, ductility and toughness both increased. The crack propagation became stable for specimens containing over a 5% volume fraction of the second phase. The fracture toughness increased up to 60% when the amount of ABS reached 20% (v/v). For larger amounts linear elastic fracture mechanics techniques could not be used properly. The effects of porosity and environmental conditions on the mechanical behavior were also studied. The mechanisms that control the fracture process were investigated by means of scanning electron microscopy.

  9. The improvement of corrosion resistance of fluoropolymer coatings by SiO{sub 2}/poly(styrene-co-butyl acrylate) nanocomposite particles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Song, R.G., E-mail: songrg@hotmail.com [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Li, X.W.; Guo, Y.Q.; Wang, C.; Jiang, Y. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China)

    2015-10-30

    Highlights: • We first proposed the feasibility of organic-inorganic hybrid particles can be used to reduce free space of the fluoropolymer coatings. • By grafting poly(styrene-co-butyl acrylate), nano-silica particles can be better dispersed in the fluoropolymer coatings system. • The coating-substrates bound strength could be obviously seen in the FESEM cross-section images. • The effects of the corrosion resistance of fluoropolymer-coated steel were investigated by potentiodynamic polarization and EIS. • Using models to analysis the anticorrosion mechanism of nanocomposite coatings. - Abstract: The effects of nano-silica particles on the anticorrosion properties of fluoropolymer coatings on mild steel have been investigated in this paper. In order to enhance the dispersibility of nano-silica in fluoropolymer coatings, we treated the surface of nano-silica with poly(styrene-co-butyl acrylate) (P(St-BA)). The surface grafting of P(St-BA) on the nanoparticles were detected using Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analyzer (TGA), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The surface of nanocomposite coatings and the coating-substrates bond texture were detected by FE-SEM. We also used energy-dispersive X-ray spectroscopy (EDS) to analyze whether the nanocomposite particles were added into the fluoropolymer coatings. In addition, the influences of various nanoparticles on the corrosion resistance of fluoropolymer-coated steel were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results shown that nanocomposite particles can be dispersed better in fluoropolymer coatings, and the electrochemical results clearly shown the improvement of the protective properties of the nanocomposite coatings when 4 wt.% SiO{sub 2}/P(St-BA) was added to the fluoropolymer coatings.

  10. Biosynthetic pathway for acrylic acid from glycerol in recombinant Escherichia coli.

    Science.gov (United States)

    Tong, Wenhua; Xu, Ying; Xian, Mo; Niu, Wei; Guo, Jiantao; Liu, Huizhou; Zhao, Guang

    2016-06-01

    Acrylic acid is an important industrial feedstock. In this study, a de novo acrylate biosynthetic pathway from inexpensive carbon source glycerol was constructed in Escherichia coli. The acrylic acid was produced from glycerol via 3-hydroxypropionaldehyde, 3-hydroxypropionyl-CoA, and acrylyl-CoA. The acrylate production was improved by screening and site-directed mutagenesis of key enzyme enoyl-CoA hydratase and chromosomal integration of some exogenous genes. Finally, our recombinant strain produced 37.7 mg/L acrylic acid under shaking flask conditions. Although the acrylate production is low, our study shows feasibility of engineering an acrylate biosynthetic pathway from inexpensive carbon source. Furthermore, the reasons for limited acrylate production and further strain optimization that should be performed in the future were also discussed.

  11. Hemocompatibility of Chitosan/poly(acrylic acid) Grafted Polyurethane Tubing

    OpenAIRE

    Lee, Hyun-Su; Tomczyk, Nancy; Kandel, Judith; Composto, Russell J.; Eckmann, David M.

    2013-01-01

    The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tu...

  12. Effects of content and surface hydrophobic modification of BaTiO3 on the cooling properties of ASA (acrylonitrile-styrene-acrylate copolymer)

    Science.gov (United States)

    Xiang, Bo; Zhang, Jun

    2018-01-01

    For the field of cool material, barium titanate (BaTiO3, BT) is still a new member that needs to be further studied. Herein, the effects of both content and surface hydrophobic modification of BT on the cooling properties of acrylonitrile-styrene-acrylate copolymer (ASA) were detailedly investigated, aiming to fabricate composited cool material. Butyl acrylate (BA) was employed to convert the surface of BT from hydrophilic to hydrophobic. The addition of unmodified BT could significantly improve the solar reflectance of ASA, especially when the addition amount is 3 vol%, the near infrared (NIR) reflectance increased from 22.02 to 72.60%. However, serious agglomeration occurred when the addition amount increased to 5 vol% and therefore led to a relatively smaller increase in solar reflectance and an obvious decline in impact strength. After surface hydrophobic modification, the modified BT (M-BT) presented better dispersibility in ASA matrix, which contributed to the improvement of both solar reflectance and impact strength. In addition, the temperature test provided a more sufficient and intuitive way to evaluate the cooling effect of the composited cool materials, and a significant decrease (over 10 °C) could be achieved in the temperature test when M-BT particles were introduced.

  13. Coating materials and solvents. 2. Acrylic acid, acrylate, and MMA; Toryo yozai. 2. Akurirusan oyobi akurirusan esuteru MMA

    Energy Technology Data Exchange (ETDEWEB)

    Akazawa, Y. [Nippon Shokubai Co. Ltd., Osaka (Japan)

    1997-09-01

    This paper describes the production process, its scale, physical properties and usage of acrylic acid, acrylate for general use, and MMA (methyl methacrylate). The propylene oxidation process is only one process for the industrial production of acrylic acid and acrylate due to its economical predominance. Annual production of acrylic acid in the world has reached to about 2.2 million tons. Relatively high growth rate is forecasted also in the future. In Japan, the acrylate is used for paints, adhesive materials, and fibers. The industrial production process of MMA includes ACH (acetone cyanhydrin) process, new ACH process, isobutylene process, MAN (methacrylonitrile) process, and ethylene carbonylation process. Demand and supply of MMA are characterized especially by the high proportion of export from Japan to the Asian region. Methacrylic resins are used for various materials, such as tail lamp lenses and meter panels of automobiles, and laser disks, CD-ROM and MD pick-ups in the field of electronic industry. Consumption of these resins is steadily extended. 16 refs., 6 figs., 7 tabs.

  14. Synthesis and characterization of superabsorbent hydrogels based on hydroxyethylcellulose and acrylic acid.

    Science.gov (United States)

    Fekete, Tamás; Borsa, Judit; Takács, Erzsébet; Wojnárovits, László

    2017-06-15

    Hydroxyethylcellulose (HEC)/acrylic acid (AAc) copolymer gels with superabsorbent properties were synthesized from aqueous solutions by radiation-initiated crosslinking. The effect of the acrylic acid content on gel properties was determined at different synthesis conditions. The partial replacement of the cellulose derivative with acrylic acid improved the gelation, leading to higher gel fraction and lower water uptake even in very low concentrations (1-5%). In the presence of acrylic acid lower dose and solute concentration was required for the gel synthesis. The molecular properties of the hydroxyethylcellulose also had a major effect on the gelation: higher molecular mass resulted in better gel properties. The acrylic acid also affected the electrolyte sensitivity of the hydrogels: while pure HEC gels were unaffected by the ionic strength of the solvent, the water uptake of HEC/AAc gels decreased with the salt concentration. The sensitivity also depended on the acrylic acid ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Catalytic Cracking of Lactide and Poly(Lactic Acid) to Acrylic Acid at Low Temperatures.

    Science.gov (United States)

    Terrade, Frédéric G; van Krieken, Jan; Verkuijl, Bastiaan J V; Bouwman, Elisabeth

    2017-05-09

    Despite being a simple dehydration reaction, the industrially relevant conversion of lactic acid to acrylic acid is particularly challenging. For the first time, the catalytic cracking of lactide and poly(lactic acid) to acrylic acid under mild conditions is reported with up to 58 % yield. This transformation is catalyzed by strong acids in the presence of bromide or chloride salts and proceeds through simple SN 2 and elimination reactions. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  16. 40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.

    Science.gov (United States)

    2010-07-01

    ... phenol, ethylene oxide adduct. 721.3700 Section 721.3700 Protection of Environment ENVIRONMENTAL..., ethylene oxide adduct. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid, ester with styrenated phenol, ethylene oxide...

  17. Synthesis of Hydrophilic and Amphiphilic Acryl Sucrose Monomers and Their Copolymerisation with Styrene, Methylmethacrylate and α- and β-Pinenes

    Directory of Open Access Journals (Sweden)

    Maria Teresa Barros

    2010-04-01

    Full Text Available Herein, we report the synthesis of monomethacryloyl sucrose esters, and their successful free radical homo- and co-polymerisation with styrene, methylmethacrylate, α- and β-pinene. The chemical, physical, structural and surface chemical properties of these polymers, containing a hydrophobic olefin backbone and hydrophilic sugar moieties as side chains, have been investigated. Biodegradation tests of the copolymer samples by a microbial fungal culture (Aspergillus niger method showed good biodegradability. The chemical structure and surface chemistry of the synthesized homo- and co-polymers demonstrate their potential technological relevance as amphiphilic and biodegradable polymers.

  18. TLC separation of hippuric, mandelic, and phenylglyoxylic acids from urine after mixed exposure to toluene and styrene

    Energy Technology Data Exchange (ETDEWEB)

    Bieniek, G.; Palys, E.; Wilczok, T.

    1982-05-01

    A method using thin-layer chromatography is described to determine the concentration of hippuric acid, mandelic acid, and phenylglyoxylic acid present in the urine after occupational mixed exposure to toluene and styrene. These substances are known metabolites of toluene and styrene, and therefore the evaluation to mixed exposure to toluene and styrene may be carried out separating these metabolites beforehand. Procedures are proposed to separate the metabolites as follows: separation of hippuric acid from mandelic acid, separation of mandelic acid from phenylglyoxylic acid, and separation of hippuric acid and mandelic acid from phenylglyoxylic acid. The developing reagent p-dimethylaminobenzaldehyde in acetic acid anhydride was used after separation on Kieselgel and Silicagel. The sensitivity of the method was 6 microgram of hippuric acid, 10 microgram of mandelic acid, and 7 microgram of phenylglyoxylic acid with an average recovery of 94.

  19. Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating

    Science.gov (United States)

    Vuong Nguyen, Thien; Nguyen, Tuan Anh; Dao, Phi Hung; Phuc Mac, Van; Hiep Nguyen, Anh; Thanh Do, Minh; Nguyen, The Huu

    2016-12-01

    This study aims to enhance the mechanical properties, thermal stability, weathering resistance and antibacterial property of a styrene acrylic polyurethane coating by adding rutile titania dioxide (R-TiO2) nanoparticles in coating formulation. The styrene acrylic polyurethane/R-TiO2 nanocomposite had been prepared by using ultrasonication. The effects of nanoparticles on the mechanical properties, thermal stability and weathering resistance of as-prepared coatings were investigated by using the adhesion strength and ball impact tests, the Fourier transform infrared and UV-vis analyses, thermogravimetric analysis (TGA), and UV/condensation weathering chamber equipped with UVA-340 fluorescent lamps, respectively. The disperse quality of nanoparticles in the coating was examined by using the field emission scanning electron microscope (FESEM). The mechanical test results showed that suitable content of R-TiO2 nanoparticles in the nanocomposite coating was 2 wt%. The FESEM images indicated that the nanoparticles were dispersed homogeneously into the entire volume of the coating. For the nanocomposite prepared by 3 h of ultrasonication, the average size of nanoparticles was in range of 40-50 nm. The ball impact and adhesion tests showed that the incorporation of nanoparticles into the coating significantly enhanced the impact strength from 120 to 145 kg cm and increased the adhesion from level 1 to level 0. The TGA test illustrated that in presence of nanoparticles, the decomposition temperature of coating increased from 146.9 °C to 154.21 °C. For the temperature at 50% loss in mass (T 50%), it was found that the T 50% of the neat coating is 351.86 °C. Adding the 2 wt% R-TiO2 nanoparticles into coating increased the T 50% value to 360.06 °C. After UV/condensation accelerated weathering test (30 cycles), the significant improvement in weight loss, impact strength and adhesion of the neat coating was observed with the presence of nanoparticles. The antibacterial test

  20. Hydrophobic surface modification of TiO2 nanoparticles for production of acrylonitrile-styrene-acrylate terpolymer/TiO2 composited cool materials

    Science.gov (United States)

    Qi, Yanli; Xiang, Bo; Tan, Wubin; Zhang, Jun

    2017-10-01

    Hydrophobic surface modification of TiO2 was conducted for production of acrylonitrile-styrene-acrylate (ASA) terpolymer/titanium dioxide (TiO2) composited cool materials. Different amount of 3-methacryloxypropyl-trimethoxysilane (MPS) was employed to change hydrophilic surface of TiO2 into hydrophobic surface. The hydrophobic organosilane chains were successfully grafted onto TiO2 through Sisbnd Osbnd Ti bonds, which were verified by Fourier transformed infrared spectra and X-ray photoelectron spectroscopy. The water contact angle of the sample added with TiO2 modified by 5 wt% MPS increased from 86° to 113°. Besides, all the ASA/TiO2 composites showed significant improvement in both solar reflectance and cooling property. The reflectance of the composites throughout the near infrared (NIR) region and the whole solar wavelength is increased by 113.92% and 43.35% compared with pristine ASA resin. Simultaneously, significant drop in temperature demonstrates excellent cooling property. A maximum decrease approach to 27 °C was observed in indoor temperature test, while a decrease around 9 °C tested outdoors is achieved.

  1. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Science.gov (United States)

    2013-09-11

    ... 20156) on behalf of Akzo Nobel Surface Chemistry, (909 Mueller Ave., Chattanooga, TN 37406) submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an exemption from the..., (7140 Heritage Village Plaza, Gainesville, VA 20156) on behalf of Akzo Nobel Surface Chemistry, (909...

  2. Polymerisation by acrylamide and acrylic acid inverse suspension

    Directory of Open Access Journals (Sweden)

    Sergio Alejandro LLoreda Blanco

    2010-04-01

    Full Text Available This work describes polymerisation by inverse suspension of acrylamide monomers and acrylic acid for forming homopolymers or copolymers This type of polymersitaion's advantages are described and reasons given for why it should be studied. The article stresses the importance of these types of monomer for obtaining materials presenting great affinity for water, such as super-absorbents and controlled liberation mechanism. Important aspects are presented such as type of initiation, monomer composition and continuous phase composition; parameters are described offering an important basis for formulating a system leading to successfully obtaining the desired materials' most relevant characteristics such as particle distribution and size polymerisation kinetics, conversion and water absorption capacity respecting the system's modifiable parameters. The foregoing is important since the product can be modified, bestowing propierties on it which are suitable for its use.

  3. Water absorbency of chitosan grafted acrylic acid hydrogels

    Science.gov (United States)

    Astrini, N.; Anah, L.; Haryono, A.

    2017-07-01

    Acrylic acid (AA) monomer was directly grafted onto chitosan (CTS) using potassium persulfate (KPS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. One factor affecting the swelling capacity of the obtained hydrogel, KPS concentration, were studied. The hydrogel products were characterized using Fourier Transform Infrared spectroscopy (FTIR) for chemical structure and scanning electron microscopy (SEM) for morphology. Swelling of the hydrogel samples in distilled water and saline solution ( 9% NaCl ) was examined. Swelling capacity of the CTS-g-PAA hydrogels in distilled water (88.53 g/g) was higher than in NaCl solution (29.94 g/g) The highest swelling capacity value was obtained when the grafted reaction was carried out using 2.5wt% initiator

  4. Crosslinkers of Different Types in Precipitation Polymerization of Acrylic Acid

    Directory of Open Access Journals (Sweden)

    H. Eshaghi

    2013-01-01

    Full Text Available Crosslinked poly(acrylic acids were prepared using two types of crosslinker by precipitation polymerization method in a binary organic solvent. N,N’-methylenebisacrylamide (MBA and polyethylene glycol dimethacrylate (PEGDMA-330 were used as low-molecular weight and long-chain crosslinkers, respectively. The effect of various types of crosslinkers on polymer characteristics (i.e., gel content, equilibrium swelling, glass transition temperature, and rheological properties was investigated. Maximum amount of viscosity was obtained by using long-chain crosslinker. The Flory-Rehner equation and rubber elasticity theory were used to discuss the network structure of polymer. It was observed that, the glass transition temperature (Tg of the synthesized polymer containing PEGDMA-330 is higher than that of polymer containing MBA. Apparent and rotational viscosity were used to determine the optimal crosslinker type. In addition, the consistencycoefficient (m and flow behavior index (n parameter of Ostwald equation were investigated as well.

  5. A stability study of plasma polymerized acrylic acid films

    Science.gov (United States)

    Cools, Pieter; Declercq, Heidi; De Geyter, Nathalie; Morent, Rino

    2018-02-01

    A medium pressure parallel-plate DBD set-up was used for the deposition of carboxylic acid-rich films using acrylic acid as precursor. A variety of discharge powers (21-33 W) and monomer flow rates (0.25-0.5 g/h) were applied to develop a range of coatings from highly unstable to completely stable in aqueous solutions. FT-IR and XPS were used to identify which coatings were stable under dynamic incubation conditions and what influence plasma operating parameters had on functional group preservation. White light interferometry was also used to calculate deposition rates (66-126 nm/min) and to determine the deposition regime (monomer deficient). Human foreskin fibroblasts were seeded onto the complete range of investigated samples and the effects of coating (in)stability on cell adhesion, viability and morphology were systematically studied. Results showed that the 27 W-0.25 g/h treatment conditions resulted in the most stable coatings. Although a concentration of only 0.7% of carboxylic acid groups was found under these experimental conditions, the positive effects of a highly acid-rich surface were still maintained as cell-material interactions were significantly enhanced.

  6. Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

    Energy Technology Data Exchange (ETDEWEB)

    Ghim, Deoukchen; Kim, Jung Hyeun [University of Seoul, Seoul (Korea, Republic of)

    2016-02-15

    Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180 .deg. peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the T{sub g} of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

  7. Controlled radical fluorination of poly(meth)acrylic acids in aqueous solution.

    Science.gov (United States)

    Dong, Yucheng; Wang, Zhentao; Li, Chaozhong

    2017-08-17

    Fluorinated alkenes exhibit very poor reactivity in copolymerization with non-fluorinated polar monomers such as acrylates. Herein we describe a convenient method for the synthesis of poly(vinyl fluoride-co-acrylic acid) and poly(2-fluoropropene-co-methacrylic acid) copolymers. Thus, the silver-catalyzed decarboxylative radical fluorination of poly(acrylic acid) with Selectfluor in water at room temperature affords poly(vinyl fluoride-co-acrylic acid) copolymers in high yields with well-defined molecular weights and polydispersities. A linear correlation is observed between the extent of fluorination and the amount of Selectfluor, indicating that the copolymer of virtually any monomer ratio can be readily accessed by controlling the amount of Selectfluor. This controlled decarboxylative fluorination is extended to poly(methacrylic acid), leading to well-defined poly(2-fluoropropene-co-methacrylic acid) copolymers.Fluorinated alkenes have very poor reactivity in copolymerizations with non-fluorinated polar monomers. Here the authors show silver-catalyzed decarboxylative radical fluorination of poly(acrylic acid) with Selectfluor in water at room temperature to form poly(vinyl fluoride-co-acrylic acid) copolymers.

  8. A key step in the formation of acrylic acid from CO2 and ethylene: the transformation of a nickelalactone into a nickel-acrylate complex.

    Science.gov (United States)

    Fischer, Reinald; Langer, Jens; Malassa, Astrid; Walther, Dirk; Görls, Helmar; Vaughan, Gavin

    2006-06-21

    The reaction of a nickelalactone with dppm, resulting in the formation of a stable binuclear Ni(I) complex with an acrylate, a Ph2P- and a dppm bridge, models a key step in the formation of acrylic acid from CO2 and ethylene.

  9. Interaction of photosensitive surfactant with DNA and poly acrylic acid

    Science.gov (United States)

    Zakrevskyy, Yuriy; Cywinski, Piotr; Cywinska, Magdalena; Paasche, Jens; Lomadze, Nino; Reich, Oliver; Löhmannsröben, Hans-Gerd; Santer, Svetlana

    2014-01-01

    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes' properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate - for the first time - complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  10. Radiation-induced synthesis of poly(acrylic acid) nanogels

    Science.gov (United States)

    Matusiak, Malgorzata; Kadlubowski, Slawomir; Ulanski, Piotr

    2018-01-01

    Nanogel is a two-component system of a diameter in the range of tens of nanometers, consisting of an intramolecularly crosslinked polymer chain and solvent, typically water, filling the space between segments of the macromolecule. Microgels are bigger than nanogels and their size range is between 100 nm to 100 μm. One of the methods used for synthesizing nanogels is linking the segments of a single macromolecule with the use of ionizing radiation, by intramolecular recombination of radiation-generated polymer radicals. The main advantage of this technique is absence of monomers, catalysts, surfactants or crosslinking agents. This method is an interesting alternative way of synthesizing polymeric carriers for biomedical applications. The aim of the study was radiation synthesis and characterization of poly(acrylic acid) - PAA - nanogels and microgels. The physico-chemical properties were described by determination of weight-average molecular weight and dimensions (radius of gyration, hydrodynamic radius) of the nanogels and microgels. Influence of polymer concentration and dose on these parameters was analyzed. Adjusting the PAA concentration and absorbed dose, one can control the molecular weight and dimensions of nanogels. The solutions of PAA were irradiated with two sources of ionizing radiation: γ-source and electron accelerator. The former method yields mainly microgels due to prevailing intermolecular crosslinking, while the latter promotes intramolecular recombination of PAA-derived radicals and in consequence formation of nanogels. In the future radiation-synthesized PAA nanogels, after functionalization, will be tested as carriers for delivering radionuclides to the tumor cells.

  11. Impact of modified graphene and microwave irradiation on thermal stability and degradation mechanism of poly (styrene-co-methyl meth acrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, Mukarram [Department of Environmental Engineering, University of Dammam, 31982 Dammam (Saudi Arabia); Shehzad, Farrukh [Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia, (Saudi Arabia); Al-Harthi, Mamdouh A., E-mail: mamdouh@kfupm.edu.sa [Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Saudi Arabia, (Saudi Arabia); Center of Research Excellence in Nanotechnology, King Fahd University of Petroleum & Minerals, 31261 Dhahran (Saudi Arabia)

    2016-06-10

    Highlights: • Modified graphene imparts thermal stability to Poly (styrene-co-methyl methacrylate) [P(st-mma)]. • The thermal stability of P(st-mma) decreased with microwave irradiation. • The thermal stability of P(st-mma)/MG nanocomposites increased with irradiation time up to 10 min and decreased subsequently. • The degradation of P(st-mma) and P(st-mma)/MG is governed by random scission model. - Abstract: Poly (styrene-co-methyl methacrylate) [P(st-mma)] composite containing 0.1 wt% modified graphene (MG) was prepared via melt blending. MG was prepared by oxidation method using nitric acid. The P(st-mma) and P(st-mma)MG composite were irradiated using microwave radiation. The degradation mechanism and thermal stability of the irradiated and un-irradiated samples was analyzed by TGA. P(st-mma)MG showed high thermal stability. The average activation energy of thermal degradation was found to be 200 kJ/mol for P(st-mma), 214 kJ/mol for P(st-mma)MG. The activation energy was highest for 10 min irradiated nanocomposites indicating an improvement in stability. The degradation mechanism was investigated by comparing the master plots constructed using the experimental data with theoretical master plots of various kinetic models. The thermal degradation of P(st-mma) and P(st-mma)MG composite before and after irradiation governs the random scission mechanism. SEM and TEM micrographs showed improved interactions and degradation of composites after 10 min and 20 min irradiation respectively.

  12. Acrylic acid derivatives of group 8 metal carbonyls: a structural and kinetic study.

    Science.gov (United States)

    Li, Bo; Kyran, Samuel J; Yeung, Andrew D; Bengali, Ashfaq A; Darensbourg, Donald J

    2013-05-06

    The synthesis, spectroscopic, and X-ray structural studies of acrylic acid complexes of iron and ruthenium tetracarbonyls are reported. In addition, the deprotonated η(2)-olefin bound acrylic acid derivative of iron as well as its alkylated species were fully characterized by X-ray crystallography. Kinetic data were determined for the replacement of acrylic acid, acrylate, and methylacrylate for the group 8 metal carbonyls by triphenylphosphine. These processes were found to be first-order in the concentration of metal complex with the rates for dissociative loss of the olefinic ligands from ruthenium being much faster than their iron analogues. However, the ruthenium derivatives afforded formation of primarily mono-phosphine metal tetracarbonyls, whereas the iron complexes led largely to trans-di-phosphine tricarbonyls. This difference in behavior was ascribed to a more stable spin crossover species (3)Fe(CO)4 which undergoes rapid CO loss to afford the bis phosphine derivative. The activation enthalpies for dissociative loss of the deprotonated η(2)-bound acrylic acid ligand were found to be larger than their corresponding values in the protonated derivatives. For example, for dissociative loss of the protonated and deprotonated acrylic acid derivatives of iron(0) the ΔH(‡) values determined were 28.0 ± 1.2 and 34.1 ± 1.5 kcal·mol(-1), respectively. Density functional theory (DFT) computations of the bond dissociation energies (BDEs) in these acrylic acids and closely related complexes were in good agreement with enthalpies of activation for these ligand substitution reactions, supportive of a dissociative mechanism for olefin displacement. Processes related to catalytic production of acrylic acid from CO2 and ethylene are considered.

  13. Thermotropic properties of phosphatidylcholine nanodiscs bounded by styrene-maleic acid copolymers.

    Science.gov (United States)

    Dominguez Pardo, J J; Dörr, J M; Renne, M F; Ould-Braham, T; Koorengevel, M C; van Steenbergen, M J; Killian, J A

    2017-11-01

    Styrene-maleic acid copolymers (SMA) have been gaining interest in the field of membrane research due to their ability to solubilize membranes into nanodics. The SMA molecules act as an amphipathic belt that surrounds the nanodiscs, whereby the hydrophobic styrene moieties can insert in between the lipid acyl chains. Here we used SMA variants with different styrene-to-maleic acid ratio (i.e. 2:1, 3:1 and 4:1) to investigate how lipid packing in the nanodiscs is affected by the presence of the polymers and how it depends on polymer composition. This was done by analyzing the thermotropic properties of a series of saturated phosphatidylcholines in nanodiscs using laurdan fluorescence and differential scanning calorimetry. In all cases it was found that the temperature of the main phase transition (Tm) of the lipids in the nanodiscs is downshifted and that its cooperativity is strongly reduced as compared to the situation in vesicles. These effects were least pronounced for lipids in nanodiscs bounded by SMA 2:1. Unexpected trends were observed for the calorimetric enthalpy of the transition, suggesting that the polymer itself contributes, possibly by rearranging around the nanodiscs when the lipids adopt the fluid phase. Finally, distinct differences in morphology were observed for nanodiscs at relatively high polymer concentrations, depending on the SMA variant used. Overall, the results suggest that the extent of preservation of native thermodynamic properties of the lipids as well as the stability of the nanodiscs at high polymer concentrations is better for SMA 2:1 than for the other SMA variants. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

    Directory of Open Access Journals (Sweden)

    Michel Oelschlägel

    2015-06-01

    The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

  15. Buffering and Antibacterial Properties of Cotton Canvas with Dolomite/ZnO-Styrene-Acrylic Complex Coating and their Comparison with Properties after the Accelerated Aging

    Directory of Open Access Journals (Sweden)

    Hana Křižova

    2017-12-01

    Full Text Available In this study, we report evaluation of buffering and self-sterilizing coating complex obtained by dolomite and zinc oxide particles incorporation into styrene–acrylic layer applied to cotton fabric. Surface properties of the coating were evaluated by SEM, EDS and 3D optical microscopy. Antimicrobial properties were determined using a mixture of G+ and G- bacteria (Escherichia coli, Staphylococcus epidermidis and Streptococcus mutans that was in dynamic contact with canvases for 4-100 hours. Alkalizing - buffer capacity of the surface layer supplied to the system by dolomite was tested by the addition of acetic acid. All these properties were simultaneously tested on the same canvases that have been previously exposed to the so-called hot (105 °C and wet aging (80 °C, 65% relative humidity. The aging was provided in the climatic test room for 144 hours and the properties of canvases before and after aging were compared and evaluated.

  16. GPCR-styrene maleic acid lipid particles (GPCR-SMALPs): their nature and potential.

    Science.gov (United States)

    Wheatley, Mark; Charlton, Jack; Jamshad, Mohammed; Routledge, Sarah J; Bailey, Sian; La-Borde, Penelope J; Azam, Maria T; Logan, Richard T; Bill, Roslyn M; Dafforn, Tim R; Poyner, David R

    2016-04-15

    G-protein-coupled receptors (GPCRs) form the largest class of membrane proteins and are an important target for therapeutic drugs. These receptors are highly dynamic proteins sampling a range of conformational states in order to fulfil their complex signalling roles. In order to fully understand GPCR signalling mechanisms it is necessary to extract the receptor protein out of the plasma membrane. Historically this has universally required detergents which inadvertently strip away the annulus of lipid in close association with the receptor and disrupt lateral pressure exerted by the bilayer. Detergent-solubilized GPCRs are very unstable which presents a serious hurdle to characterization by biophysical methods. A range of strategies have been developed to ameliorate the detrimental effect of removing the receptor from the membrane including amphipols and reconstitution into nanodics stabilized by membrane scaffolding proteins (MSPs) but they all require exposure to detergent. Poly(styrene-co-maleic acid) (SMA) incorporates into membranes and spontaneously forms nanoscale poly(styrene-co-maleic acid) lipid particles (SMALPs), effectively acting like a 'molecular pastry cutter' to 'solubilize' GPCRs in the complete absence of detergent at any stage and with preservation of the native annular lipid throughout the process. GPCR-SMALPs have similar pharmacological properties to membrane-bound receptor, exhibit enhanced stability compared with detergent-solubilized receptors and being non-proteinaceous in nature, are fully compatible with downstream biophysical analysis of the encapsulated GPCR. © 2016 Authors; published by Portland Press Limited.

  17. Supercritical water oxidation of acrylic acid production wastewater.

    Science.gov (United States)

    Gong, Y M; Wang, S Z; Tang, X Y; Xu, D H; Ma, H H

    2014-01-01

    Supercritical water oxidation (SCWO) of wastewater from an acrylic acid manufacturing plant has been studied on a continuous flow experimental system, whose reactor was made of Hastelloy C-276. Experimental conditions included a reaction temperature (T) ranging from 673 to 773K, a residence time (t) ranging from 72.7 to 339s, a constant pressure (P) of 25 MPa and a fixed oxidation coefficient (alpha) of 2.0. Experimental results indicated that reaction temperature and residence time had significant influences on the oxidation reaction, and increasing the two operation parameters could improve both degradation of chemical oxygen demand (COD) and ammonia nitrogen (NH3-N). The COD removal efficiency could reach up to 98.73% at 25 MPa, 773 K and 180.1 s, whereas the destruction efficiency of NH3-N was only 43.71%. We further carried out a kinetic analysis considering the induction period through free radical chain mechanism. It confirms that the power-law rate equation for COD removal was 345 exp(-52200/RT)[COD]1.98[O2]0.17 and for NH3-N removal was 500 exp(-64492.19/RT)[NH3-N]1.87 [O2]0.03. Moreover, the induction time formulations for COD and NH3-N were suspected to be exp(38250/RT)/173 and exp(55690/RT)/15231, respectively. Correspondingly, induction time changed from 2.22 to 5.38 s for COD and 0.38 to 1.38 s for NH3-N. Owing to the catalysis of reactor inner wall surface, more than 97% COD removal was achieved in all samples.

  18. Polymorphism and polymerisation of acrylic and methacrylic acid at high pressure

    DEFF Research Database (Denmark)

    Oswald, Iain D. H.; Urquhart, Andrew J.

    2011-01-01

    The polymorphism and polymerisation of two related acids have been investigated under high pressure conditions. Acrylic acid crystallises as a new polymorph at 0.65 GPa whilst methacrylic acid crystallises in a new polymorph at a higher pressure of 1.5 GPa. Both these new polymorphs exhibit similar...

  19. DISPERSION POLYMERIZATION OF STYRENE IN SUPERCRITICAL CARBON DIOXIDE UTILIZING RANDOM COPOLYMERS INCLUDING FLUORINATED ACRYLATE FOR PREPARING MICRON-SIZE POLYSTYRENE PARTICLES. (R826115)

    Science.gov (United States)

    The dispersion polymerization of styrene in supercritical CO2 utilizing CO2-philic random copolymers was investigated. The resulting high yield of polystyrene particles in the micron-size range was formed using various random copolymers as stabilizers. The p...

  20. The role of acrylic acid impurity as a sensitizing component in electrocardiogram electrodes.

    Science.gov (United States)

    Stingeni, Luca; Cerulli, Emilia; Spalletti, Anna; Mazzoli, Alessandra; Rigano, Luigi; Bianchi, Leonardo; Hansel, Katharina

    2015-07-01

    Allergic contact dermatitis caused by (meth)acrylates is well known, both in occupational and in non-occupational settings. Contact hypersensitivity to electrocardiogram (ECG) electrodes containing (meth)acrylates is rarely reported. To report the first case of contact dermatitis caused by acrylic acid impurity in ECG electrodes. Patch tests were performed with separate components of electrodes and some (meth)acrylates. This was followed by high-performance liquid chromatography of electrode hydrogel. The patient was contact-allergic to electrode hydrogel but not to its separate constituents. Positive reactions were observed to 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxypropyl methacrylate (2-HPMA) and ethyleneglycol dimethacrylate (EGDMA). Subsequent analysis showed that the electrode hydrogel contained acrylic acid as an impurity. The latter was subsequently patch tested, with a positive result. The sensitization resulting from direct contact with ECG electrodes was caused by acrylic acid, present as an impurity in ECG electrodes. Positive reactions to 2-HEMA, 2-HPMA and EGDMA are considered to be cross-reactions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Polystyrene-b-poly(tert-butyl acrylate) and polystyrene-b-poly(acrylic acid) dendrimer-like copolymers: two-dimensional self-assembly at the air-water interface.

    Science.gov (United States)

    Joncheray, Thomas J; Bernard, Sophie A; Matmour, Rachid; Lepoittevin, Bénédicte; El-Khouri, Rita J; Taton, Daniel; Gnanou, Yves; Duran, Randolph S

    2007-02-27

    The two-dimensional self-assembly at the air/water (A/W) interface of two dendrimer-like copolymers based on polystyrene and poly(tert-butyl acrylate) (PS-b-PtBA) or poly(acrylic acid) (PS-b-PAA) was investigated through surface pressure measurements (isotherms, isochores, and compression-expansion hysteresis experiments) and atomic force microscopy (AFM) imaging. The two dendrimer-like block copolymers have an 8-arm PS core (Mn = 10 000 g/mol, approximately 12 styrene repeat units per arm) with a 16-arm PtBA (Mn = 230 000 g/mol, approximately 112 tert-butyl acrylate repeat units per arm) or PAA (Mn = 129 000 g/mol, approximately 112 acrylic acid repeat units per arm) corona. The PS-b-PtBA sample forms stable Langmuir monolayers and aggregates into circular surface micelles up to a plateau observed in the corresponding isotherm around 24 mN/m. Beyond this threshold, the monolayers collapse above the interface, resulting in the formation of large and irregular desorbed aggregates. The PS-b-PAA sample has ionizable carboxylic acid groups, and its A/W interfacial self-assembly was therefore investigated for various subphase pH values. Under basic conditions (pH = 11), the carboxylic acid groups are deprotonated, and the PS-b-PAA sample is therefore highly water-soluble and does not form stable monolayers, instead irreversibly dissolving in the aqueous subphase. Under acidic conditions (pH = 2.5), the PS-b-PAA sample is less water-soluble and becomes surface-active. The pseudoplateau observed in the isotherm around 5 mN/m corresponds to a pancake-to-brush transition with the PAA chains dissolving in the water subphase and stretching underneath the anchoring PS cores. AFM imaging revealed the presence of circular surface micelles for low surface pressures, whereas the biphasic nature of the pseudoplateau region was confirmed with the gradual aggregation of the micellar PS cores above the PAA chains. The aggregation numbers for both samples were estimated around 3

  2. Synthesis of radiation crosslinked poly(acrylic acid) in the presence of phenyltriethoxysilane

    Science.gov (United States)

    Hassan, Safia; Yasin, Tariq

    2014-04-01

    Acrylic acid based superabsorbent hydrogel was prepared using phenyltriethoxysilane (PTES) as polyfunctional monomer. Different amounts of PTES were incorporated in acrylic acid and irradiated at different doses upto maximum of 30 kGy. The crosslinked acrylic acid showed hydrogel properties and its swelling kinetics, gel fraction and equilibrium degree of swelling (EDS) were studied. It was found that the increased PTES concentration decreased the EDS of the hydrogels. Infrared spectroscopy confirmed the crosslinking reaction between the feed components and the existence of siloxane bond. Thermogravimetric analysis showed an increase in the stability of the hydrogels having high PTES content. The swelling of the hydrogel was affected by pH, ionic strength and temperature. These hydrogels showed low swelling in acidic and basic pH range and high swelling around neutral pH. This switchable pH response of these hydrogels can be exploited in environmental and biomedical applications.

  3. Temperature dependence of the heterogeneous uptake of acrylic acid on Arizona test dust.

    Science.gov (United States)

    Liu, Qifan; Wang, Yidan; Wu, Lingyan; Jing, Bo; Tong, Shengrui; Wang, Weigang; Ge, Maofa

    2017-03-01

    In this study, the temperature dependence of the heterogeneous uptake of acrylic acid on Arizona test dust (ATD) has been investigated within a temperature range of 255-315K using a Knudsen cell reactor. Combined with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiment, it was found that acrylic acid could adsorb on ATD via surface OH groups and convert to carboxylate on the particle surface. The kinetics study suggests that the initial true uptake coefficient (γt) of acrylic acid on ATD decreases from (4.02±0.12)×10(-5) to (1.73±0.05)×10(-5) with a temperature increase from 255 to 315K. According to the temperature dependence of uptake coefficients, the enthalpy (ΔHobs) and entropy (ΔSobs) of uptake processes were determined to be -(9.60±0.38) KJ/mol and -(121.55±1.33) J·K/mol, respectively. The activation energy for desorption (Edes) was calculated to be (14.57±0.60) KJ/mol. These results indicated that the heterogeneous uptake of acrylic acid on ATD surface was sensitive to temperature. The heterogeneous uptake on ATD could affect the concentration of acrylic acid in the atmosphere, especially at low temperature. Copyright © 2016. Published by Elsevier B.V.

  4. Synthesis of a novel acrylated abietic acid-g-bacterial cellulose hydrogel by gamma irradiation.

    Science.gov (United States)

    Abeer, Muhammad Mustafa; Amin, Mohd Cairul Iqbal Mohd; Lazim, Azwan Mat; Pandey, Manisha; Martin, Claire

    2014-09-22

    Acrylated abietic acid (acrylated AbA) and acrylated abietic acid-grafted bacterial cellulose pH sensitive hydrogel (acrylated AbA-g-BC) were prepared by a one-pot synthesis. The successful dimerization of acrylic acid (AA) and abietic acid (AbA) and grafting of the dimer onto bacterial cellulose (BC) was confirmed by 13C solid state NMR as well as FT-IR. X-ray diffraction analysis showed characteristic peaks for AbA and BC; further, there was no effect of increasing amorphous AA content on the overall crystallinity of the hydrogel. Differential scanning calorimetry revealed a glass transition temperature of 80°C. Gel fraction and swelling studies gave insight into the features of the hydrogel, suggesting that it was suitable for future applications such as drug delivery. Scanning electron microscopy observations showed an interesting interpenetrating network within the walls of hydrogel samples with the lowest levels of AA and gamma radiation doses. Cell viability test revealed that the synthesized hydrogel is safe for future use in biomedical applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Direct Synthesis of Hyperbranched Poly(acrylic acid-co-3-hydroxypropionate

    Directory of Open Access Journals (Sweden)

    Efkan Çatıker

    2015-01-01

    Full Text Available Hyperbranched poly(acrylic acid-co-3-hydroxypropionate (PAcHP was synthesized by base-catalyzed hydrogen transfer polymerization of acrylic acid through one step. The copolymers obtained through solution and bulk polymerization were insoluble in water and all organic solvents tried. Structural and compositional characterizations of hyperbranched PAcHP were performed by using FTIR, solid 13C-NMR, TGA, and titrimetric analysis. Acrylate fraction of the hyperbranched PAcHP obtained via bulk polymerization was determined as 60–65% by comparing TGA curves of hyperbranched PAcHP and pure poly(3-hydroxy propionate (PHP. However, analytical titration of the same sample revealed that acrylic acid units were about 47.3%. The results obtained from TGA and analytical titration were used to evaluate the chemical structure of the copolymer. Hyperbranched PAcHP exhibited hydrogel properties. Swelling behavior of the copolymer was investigated at a wide pH range and ionic strength. The dynamic swelling profiles of hyperbranched PAcHP exhibited a fast swelling behavior in the first hour and achieved the equilibrium state within 12 h in PBS. Depending on the conditions, the copolymers exhibited swelling ratios up to 2100%. As the copolymer has easily biodegradable propionate and versatile functional acrylic acid units, it can be used as not only biodegradable material in medical applications but also raw material in personal care commodities.

  6. Evaluation of Liquid-Liquid Extraction Process for Separating Acrylic Acid Produced From Renewable Sugars

    Science.gov (United States)

    Alvarez, M. E. T.; Moraes, E. B.; Machado, A. B.; Maciel Filho, R.; Wolf-Maciel, M. R.

    In this article, the separation and the purification of the acrylic acid produced from renewable sugars were studied using the liquid-liquid extraction process. Nonrandom two-liquids and universal quasi-chemical models and the prediction method univeral quasi-chemical functional activity coefficients were used for generating liquid-liquid equilibrium diagrams for systems made up of acrylic acid, water, and solvents (diisopropyl ether, isopropyl acetate, 2-ethyl hexanol, and methyl isobutyl ketone) and the results were compared with available liquid-liquid equilibrium experimental data. Aspen Plus (Aspen Technology, Inc., version 2004.1) software was used for equilibrium and process calculations. High concentration of acrylic acid was obtained in this article using diisopropyl ether as solvent.

  7. Radiation synthesis of superabsorbent poly(acrylic acid)-carrageenan hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju; Kumar, Manmohan; Varshney, Lalit E-mail: lalitv@magnum.barc.ernet.in

    2004-04-01

    A series of superabsorbent hydrogels were prepared from carrageenan and partially neutralized acrylic acid by gamma irradiation at room temperature. The gel fraction, swelling kinetics and the equilibrium degree of swelling (EDS) of the hydrogels were studied. It was found that the incorporation of even 1% carrageenan (sodium salt) increases the EDS of the hydrogels from {approx}320 to {approx}800 g/g. Thermal analysis were carried out to determine the amount of free water and bound water in the hydrogels. Under optimum conditions, poly(acrylic acid)-carrageenan hydrogels with high gel fraction ({approx}80%) and very high EDS ({approx}800 g/g) were prepared gamma radiolytically from aqueous solution containing 15% partially neutralized acrylic acid and 1-5% carrageenan. The hydrogels were also found to be sensitive to the pH and the ionic strength of the medium.

  8. Acrylic acid surface-modified contact lens for the culture of limbal stem cells.

    Science.gov (United States)

    Zhang, Hong; Brown, Karl David; Lowe, Sue Peng; Liu, Guei-Sheung; Steele, David; Abberton, Keren; Daniell, Mark

    2014-06-01

    Surface treatment to a biomaterial surface has been shown to modify and help cell growth. Our aim was to determine the best surface-modified system for the treatment of limbal stem cell deficiency (LSCD), which would facilitate expansion of autologous limbal epithelial cells, while maintaining cultivated epithelial cells in a less differentiated state. Commercially available contact lenses (CLs) were variously surface modified by plasma polymerization with ratios of acrylic acid to octadiene tested at 100% acrylic acid, 50:50% acrylic acid:octadiene, and 100% octadiene to produce high-, mid-, and no-acid. X-ray photoelectron spectroscopy was used to analyze the chemical composition of the plasma polymer deposited layer. Limbal explants cultured on high acid-modified CLs outgrew more cells. Immunofluorescence and RT2-PCR array results indicated that a higher acrylic acid content can also help maintain progenitor cells during ex vivo expansion of epithelial cells. This study provides the first evidence for the ability of high acid-modified CLs to preserve the stemness and to be used as substrates for the culture of limbal cells in the treatment of LSCD.

  9. Screening of Catalyst and Important Variable for The Esterification of Acrylic Acid with 2 Ethylhexanol

    Science.gov (United States)

    Ahmad, M. A. A.; Chin, S. Y.

    2017-06-01

    The global demand of 2-ethylhexyl acrylate (2EHA) market has witnessed a significant growth in the past few years and this growth is anticipated to increase in the coming years. 2EHA is one of the basic organic building blocks that mainly used in the production of coatings, adhesives, superabsorbents, thickeners and plastic additives. Homogenous acid-catalysed esterification of acrylic acid (AA) with 2-ethylhexanol (2EH) is commonly used for the production of 2EHA. The homogeneous catalysts such as sulfuric and para-toluene sulfonic acid have resulted the costly and complicated downstream process that generates acidic, corrosive and non-environmental friendly waste. Therefore, it is importance to develop a cheaper process that employing heterogeneous catalysts and alternative raw material from wastewater containing acrylic acid. In this research, the study for the esterification of AA with 2EH catalysed by ion-exchange resin was conducted. The best sulfonic acid functional cation-exchange resin among SK104, SK1B, PK208, PK216, PK228, RCP145, and RCP160 was screened. PK208 outperformed the other resins and it was used subsequently in the parametric studies. The effect of important parameters (initial concentration of acrylic acid (AA), temperature, molar ratio of reactant (AA and 2EH), catalyst loading, and polymerisation inhibitor loading) was studied using 2 factorial design to determine the significant parameters to the esterification. It was found that the initial concentration of AA and temperature were most significantly affecting the esterification of AA with 2EH.

  10. Effects of gas atmospheres on poly(lactic acid) film in acrylic acid plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yun, E-mail: yun.zhaotju@yahoo.com [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Fina, Alberto [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino – sede di Alessandria, V. T. Michel 5, 15121 Alessandria (Italy); Venturello, Alberto; Geobaldo, Francesco [Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

    2013-10-15

    Plasma polymerized acrylic acid (AA) coatings were deposited on poly(lactic acid) (PLA) films in various gas atmospheres during the pre-treatment of PLA and the deposition of AA, respectively. Therefore, this work was twofold: the argon pretreated PLA films followed by a deposition in argon were investigated against the mixture of argon and oxygen pretreated ones under the same deposition conditions; the plasma deposition of AA operating in different atmospheres (argon, oxygen and nitrogen) was employed to modify the pretreated PLA in oxygen. Chemical and physical changes on the plasma-treated surfaces were examined using contact angle, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and attenuated total reflection infrared (ATR-FTIR) analysis. The results showed that the discharge gas can have a significant influence on the chemical composition of the PLA surfaces: oxygen plasmas introduced oxygen-containing groups in company with surface etching in pretreatment and deposition, while argon discharges was able to achieve much better hydrophilic behavior and high retention ratio of poly(acrylic acid) (PAA) coating before and after washing in water.

  11. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan

    OpenAIRE

    Hortensia Ortega-Ortiz; Baltazar Gutiérrez-Rodríguez; Gregorio Cadenas-Pliego; Luis Ibarra Jimenez

    2010-01-01

    The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 pr...

  12. [Bonding of MMA-BPO. DMPT resin to bovine tooth coated by poly (methyl methacrylate-co-p-styrene sulfonic acid)].

    Science.gov (United States)

    Kinoshita, T; Yamamoto, T; Nagata, K; Nakabayashi, N

    1989-11-01

    The objective of this study was to prepare a new type water-soluble bonding agent, methyl methacrylate (MMA)-p-styrene sulfonic acid copolymer (MS), and to investigate the effect of MS on bonding between resins and tooth substrates. MS is cross-linked with Ca2+ released from ground enamel and dentin and could be immobilized on their surface. A sample was prepared by bonding an acrylic rod with a BPO-amine catalyzed self-curing resin to ground enamel and dentin coated with an aqueous mixture of FeCl3 and 10 wt% MS. After immersion in water for 24 hrs, the tensile bond strength was measured. The bond strength to both enamel and dentin was only 2 MPa and adhesive failure occurred at the interface between cured MS and self-curing resin. This suggested that cured MS could adversely effect the polymerization of self-curing resins. A second treatment of cured MS on the tooth surface with metallic cations was carried out to minimize the amount of free sulfonic acids in the MS disturbing radical formation in self-curing resin. The second treatment improved the bond strength to 6 MPa.

  13. PREPARATION OF BLOCK COPOLYMERS OF POLY(STYRENE) AND POLY(T-BUTYL ACRYLATE) OF VARIOUS MOLECULAR WEIGHTS AND ARCHITECTURES BY ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

    Science.gov (United States)

    Block copolymers of polystyrene and poly(t-butyl acrylate) were prepared using atom transfer radical polymerization techniques. These polymers were synthesized with a CuBr/N,N,N,NElectroactive behavior assessment of poly(acrylic acid)-graphene oxide composite hydrogel in the detection of cadmium

    NARCIS (Netherlands)

    Bejarano-Jimenez, A.; Escobar-Barrios, V.A.; Kleijn, J.M.; Oritz-Ledon, C.A.; Chazaro-Ruiz, L.F.

    2014-01-01

    Super absorbent polymers of acrylic acid-graphene oxide (PAA-GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous

  14. Thin film of Poly(acrylic acid-co-allyl acrylate as a Sacrificial Protective Layer for Hydrophilic Self Cleaning Glass

    Directory of Open Access Journals (Sweden)

    Jānis Lejnieks

    2010-05-01

    Full Text Available Poly(acrylic acid-co-allyl acrylate statistical copolymers were synthesized in a controlled manner in two steps: first tert.butyl acrylate and allyl acrylate were polymerized via atom transfer radical polymerization (ATRP and afterwords the tert.butyl protective groups were removed via hydrolysis. Samples of self cleaning glass (SCG were coated with thin films of poly(acrylic acid-co-allyl acrylate and cross-linked afterwards by UV irradiation (in the presence of a photoinitiator and an accelerator. Solution cast thin films were transparent and homogeneous before and after UV cross-linking. The irradiated samples were found to be hydrophilic (Θ < 20° and water insoluble. The coating prevented the spontaneous hydrophobization of the SCG by residual silicon exhaled from the sealing material. The TiO2 photocatalyst that covers the glass surface was found to strip the protective coating. The rate of the photooxidation process was measured by IR spectroscopy. The real field performance of the protective coating was also tested.

  15. Poly(acrylic acid) to induce competitive crystallization of a theophylline/oxalic acid cocrystal and a theophylline polymorph

    Science.gov (United States)

    Jang, Jisun; Kim, Il Won

    2016-01-01

    Polymeric additives to induce competitive crystallization of pharmaceutical compounds were explored. A cocrystal of theophylline and oxalic acid was used as a model system, and poly(acrylic acid), poly(caprolactone), and poly(ethylene glycol) were the additives. The cocrystal formation was selectively hindered with addition of poly(acrylic acid). First the size of the cocrystals were reduced, and eventually the cocrystallization was inhibited to generate neat theophylline crystals. The theophylline crystals were of a distinctively different crystal structure from known polymorphs, based on powder X-ray diffraction. They were also obtained in nanoscale size, when millimeter-scale crystals formed without poly(acrylic acid). Polymeric additives that could form specific interactions with crystallizing compounds seem to be useful tools for the phase and size control of pharmaceutical crystals.

  16. An effective method and pathways of acrylonitrile degradation to acrylic acid through an alkaline hydrothermal system.

    Science.gov (United States)

    Dong, Wenjie; Peng, Boyu; Wang, Ke; Miao, Jia; Zhang, Wei; Zhang, Yalei; Shen, Zheng

    2017-07-01

    Degradation of pollution for specific chemicals represents an optimal approach to high-strength wastewater treatment. One-pot selective conversion of acrylonitrile to acrylic acid in a hydrothermal system with NaOH as a catalyst was carried out. The influence factors were evaluated, including initial acrylonitrile concentration, reaction temperature, reaction time and amount of alkali. Experimental results showed that the highest yield of acrylic acid (55%) was obtained at the initial acrylonitrile concentration of 3 × 10(3) mg/L, 300°C for 90 s with 1.0 M NaOH. To determine the reaction path, intermediates analysis and calculation of carbon and nitrogen balance were carried out by means of HPLC, GC and TOC/TN methods. Two probable reaction pathways were proposed as follows: (1) Acrylonitrile was hydrolyzed into acrylamide, and acrylic acid was obtained via further hydrolysis. (2) Acrylonitrile was converted into 3-hydroxy-propionitrile via additive reaction, and this product was readily converted to 3-hydroxy-propionic acid through two steps of hydrolysis, followed by dehydration reaction to produce acrylic acid. This study offered not only an efficient method to transfer highly toxic pollutants into valuable chemical, but also a better understanding of hydrothermal alkali catalytic reaction.

  17. Bio-based acrylic acid from sugar via propylene glycol and allyl alcohol

    NARCIS (Netherlands)

    Pramod, C. V.; Fauziah, R.; Seshan, K.; Lange, J. P.

    2018-01-01

    A new route for producing bio-based acrylic acid is proposed. It starts with the conversion of carbohydrates to propylene glycol, being main or by-product, and proceeds via a subsequent dehydration to allyl alcohol under gas-phase conditions over K-modified ZrO2 and a final oxidation over MoWVOx

  18. 40 CFR 721.321 - Substituted acrylamides and acrylic acid copolymer (generic).

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant... identified generically as substituted acrylamides and acrylic acid copolymer (PMN P-00-0490) is subject to... of this part apply to this section except as modified by this paragraph. (1) Recordkeeping...

  19. Dielectric properties of solution-grown-undoped and acrylic-acid ...

    Indian Academy of Sciences (India)

    Dielectric capacities and losses were measured, in the temperature (50–170°C) and frequency (01–100 kHz range), for undoped and acrylic acid (AA) doped ethyl cellulose (EC) films (thickness about 20 m) with progressive increase in the concentration of dopant in the polymer matrix. The variation of capacity with ...

  1. Bioconversion of acrylonitrile to acrylic acid by rhodococcus ruber strain AKSH-84.

    Science.gov (United States)

    Kamal, Ahmed; Kumar, M Shiva; Kumar, C Ganesh; Shaik, Thokhir

    2011-01-01

    A new versatile acrylonitrile-bioconverting strain isolated from a petroleum-contaminated sludge sample and identified as Rhodococcus ruber AKSH-84 was used for optimization of medium and biotransformation conditions for nitrilase activity to produce acrylic acid. A simple and rapid HPLC protocol was optimized for quantification of acrylic acid, acrylamide, and acrylonitrile. The optimal medium conditions for nitrilase activity were pH of 7.0, temperature of 30degreesC, agitation of 150 rpm, and inoculum level of 2%. Glycerol as a carbon source and sodium nitrate as the nitrogen source provided good nutritional sources for achieving good biotransformation. Nitrilase activity was constitutive in nature and was in the exponential growth phase after 24 h of incubation under optimal conditions without addition of any inducer. The substrate preference was acrylonitrile and acetonitrile. The present work demonstrates the biotransformation of acrylonitrile to acrylic acid with the new strain, R. ruber AKSH-84, which can be used in green biosynthesis of acrylic acid for biotechnological processes. The nitrilase produced by the isolate was purified and characterized.

  2. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly(epsilon-caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2009-01-01

    Amphiphilic poly(epsilon-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) with a thiol functionality in the PCL terminal has been prepared in a novel synthetic cascade. Initially, living anionic ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) employing the difunctional......) of tent-butyl acrylate (tBA) in a controlled fashion by use of NiBr2(PPh3)(2) catalyst to produce Prot-PCL-b-PtBA with narrow polydispersities (1.17-1.39). Subsequent mild deprotection protocols provided HS-PCL-b-PAA. Reduction of a gold salt in the presence of this macroligand under thiol...

  3. Eco-friendly Crosslinking Agent for Acid Functional Acrylic Resin

    Directory of Open Access Journals (Sweden)

    Archana Shah

    2009-01-01

    Full Text Available Oil from J. multifida was extracted and it was first converted into N,N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA. HEJFA has been synthesized by reaction between Jatropha oil and diethanol amine in presence of zinc oxide as a catalyst. The reaction is relatively rapid and proceeded to high yield at 200±5 OC. The resulting HEJFA was used to formulate thermosetting coating compositions. Films were cured at ambient (air drying and elevated (stove drying temperatures using N, N-bis(2-hydroxyethyl Jatropha fatty amide (HEJFA as eco-friendly crosslinking agent for acrylic resin. The coating performance of the various compositions was tested by measurement of scratch hardness, impact strength and chemical resistance. The results show better performance of the HEJFA based compositions compared to butylated melamine formaldehyde (MF based compositions.

  4. Synthesis of dense poly(acrylic acid) brushes and their interaction with amine-functional silsesquioxane nanoparticles

    NARCIS (Netherlands)

    Retsch, Markus; Walther, Andreas; Loos, Katja; Mueller, Axel H. E.; Müller, Axel H.E.

    2008-01-01

    Poly(acrylic acid) polyetectrolyte brushes were synthesized by surface-initiated atom transfer radical polymerization (SI-ATRP) of tert-butyl acrylate on planar gold surfaces and subsequent hydrolysis. Three types of monolayers with different numbers of thiol binding sites per initiating unit were

  5. Influence of Poly(styrene-co-maleic acid) Copolymer Structure on the Properties and Self-Assembly of SMALP Nanodiscs.

    Science.gov (United States)

    Hall, Stephen C L; Tognoloni, Cecilia; Price, Gareth J; Klumperman, Bert; Edler, Karen J; Dafforn, Tim R; Arnold, Thomas

    2018-01-16

    Polymer stabilized nanodiscs are self-assembled structures composed of a polymer belt that wraps around a segment of lipid bilayer, and as such are capable of encapsulating membrane proteins directly from the cell membrane. To date, most studies on these nanodiscs have used poly(styrene-co-maleic acid) (SMA) with the term SMA-lipid particles (SMALPs) coined to describe them. In this study, we have determined the physical and thermodynamic properties of such nanodiscs made with two different SMA copolymers. These include a widely used and commercially available statistical poly(styrene-co-maleic acid) copolymer (coSMA) and a reversible addition-fragmentation chain transfer synthesized copolymer with narrow molecular weight distribution and alternating styrene and maleic acid groups with a polystyrene tail, (altSMA). We define phase diagrams for each polymer, and show that, regardless of polymer topological structure, self-assembly is driven by the free energy change associated with the polymers. We also show that nanodisc size is polymer dependent, but can be modified by varying polymer concentration. The thermal stability of each nanodisc type is similar, and both can effectively solubilize proteins from the E. coli membrane. These data show the potential for the development of different SMA polymers with controllable properties to produce nanodiscs that can be optimized for specific applications and will enable more optimized and widespread use of the SMA-based nanodiscs in membrane protein research.

  6. All-acrylic superelastomers: facile synthesis and exceptional mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei [Department of Chemistry; University of Tennessee; Knoxville; USA; Goodwin, Andrew [Department of Chemistry; University of Tennessee; Knoxville; USA; Wang, Yangyang [Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; USA; Yin, Panchao [Chemical and Engineering Materials Division; Oak Ridge National Laboratory; Oak Ridge; USA; Wang, Weiyu [Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; USA; Zhu, Jiahua [Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; USA; Wu, Ting [Department of Materials Science and Engineering; University of Tennessee; Knoxville; USA; Lu, Xinyi [Department of Chemistry; University of Tennessee; Knoxville; USA; Hu, Bin [Department of Materials Science and Engineering; University of Tennessee; Knoxville; USA; Hong, Kunlun [Center for Nanophase Materials Sciences; Oak Ridge National Laboratory; Oak Ridge; USA; Kang, Nam-Goo [Department of Chemistry; University of Tennessee; Knoxville; USA; Mays, Jimmy [Department of Chemistry; University of Tennessee; Knoxville; USA

    2018-01-01

    All-acrylic multigraft copolymers made by a facile synthesis procedure exhibit elongation at break >1700% and strain recovery behavior far exceeding those of commercial acrylic and styrenic triblock copolymers.

  7. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: psbcguo@scut.edu.cn; Lei Yanda; Chen Feng; Liu Xiaoliang; Du Mingliang; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2008-12-30

    Methacrylic acid (MAA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed interaction mechanisms of MAA and the in situ formed zinc methacrylate (ZDMA) were revealed by X-ray diffraction (XRD), surface area and porosity analysis, X-ray photoelectron spectroscopy (XPS) together with crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through ZDMA and MAA intermediated linkages. ZDMA connects SBR and HNTs via grafting/complexation mechanism. MAA bonds SBR and HNTs through grafting/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and MAA or ZDMA was achieved. Effects of MAA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of MAA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and MAA or ZDMA and the largely improved dispersion of HNTs.

  8. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by sorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun, E-mail: psbcguo@scut.edu.cn [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China); Chen Feng; Lei Yanda; Liu Xiaoliang; Wan Jingjing; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2009-05-30

    Sorbic acid (SA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed mechanisms for the largely improved performance were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), porosity analysis and crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through SA intermediated linkages. SA bonds SBR and HNTs through grafting copolymerization/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and SA was achieved. Formation of zinc disorbate (ZDS) was revealed during the vulcanization of the composites. However, in the present systems, the contribution of ZDS to the reinforcement was limited. Effects of SA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of SA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and SA and the largely improved dispersion of HNTs.

  9. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by sorbic acid

    Science.gov (United States)

    Guo, Baochun; Chen, Feng; Lei, Yanda; Liu, Xiaoliang; Wan, Jingjing; Jia, Demin

    2009-05-01

    Sorbic acid (SA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed mechanisms for the largely improved performance were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), porosity analysis and crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through SA intermediated linkages. SA bonds SBR and HNTs through grafting copolymerization/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and SA was achieved. Formation of zinc disorbate (ZDS) was revealed during the vulcanization of the composites. However, in the present systems, the contribution of ZDS to the reinforcement was limited. Effects of SA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of SA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and SA and the largely improved dispersion of HNTs.

  10. Fluconazole release from hydrogels including acrylamide-acrylic acid-itaconic acid, and their microbiological interactions.

    Science.gov (United States)

    Pulat, Mehlika; Eksi, Haslet; Abbasoglu, Ufuk

    2008-01-01

    Polyacrylamide (PAAm), polyacrylic acid (PAA), poly(acrylamide-co-itaconic acid) (PAAmIA) and poly(acrylic acid-co-itaconic acid) (PAAIA) hydrogels were prepared via free-radical polymerization using ethylene glycol dimethacrylate (EGDMA) as cross-linker. The variations of swelling percentages with time and pH were determined for these hydrogels at 37 degrees C. PAAmIA was found as the most swollen hydrogel at pH 4.0. SEM micrographs were taken to observe the morphology of the hydrogels. The less swollen hydrogel, PAAIA, displays less porosity relative to PAAmIA hydrogel. Fluconazole was entrapped into PAAmIA and PAAIA hydrogels and the release was investigated in Britton-Robinson buffer solution (BR) at pH 4.0 and 37 degrees C. The kinetic release parameters of the hydrogels, n and k, were calculated and Fickian-type diffusion was established for PAAmIA, which releases Fluconazole faster than PAAIA hydrogel. Therapeutic range was reached in the first hour for both hydrogels. Microbiological interactions of hydrogels were also studied in vitro in vaginal medium. It is found that Fluconazole entrapped in hydrogels inhibited the growth of Candida albicans.

  11. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  12. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  13. Photo-Reversible Supramolecular Hydrogels Assembled by α-Cyclodextrin and Azobenzene Substituted Poly(acrylic acid)s

    NARCIS (Netherlands)

    Wang, Mingwei; Zhang, Xiaojun; Li, Li; Wang, Junyou; Wang, Jie; Ma, Jun; Yuan, Zhenyu; Lincoln, Stephen F.; Guo, Xuhong

    2016-01-01

    Photo-reversible supramolecular hydrogels based on the mixture of α-cyclodextrin (α-CD) and azobenzene (Azo) substituted poly(acrylic acid) s were prepared. Effects of substitution degree of Azo, polymer concentration and tethered chain length on the reversible sol-gel transition of these

  14. Waveguide CP-FTMW and millimeter wave spectra of s-cis- and s-trans-acrylic acid

    Science.gov (United States)

    Alonso, E. R.; Kolesniková, L.; Peña, I.; Shipman, S. T.; Tercero, B.; Cernicharo, J.; Alonso, J. L.

    2015-10-01

    The millimeter wave spectrum of acrylic acid (CH2dbnd CHsbnd COOH), the simplest unsaturated carboxylic acid, was measured and analyzed from 130 to 360 GHz. Additional measurements from 18 to 26.5 GHz were also made using a waveguide CP-FTMW spectrometer. More than 4000 rotational lines were assigned to s-cis- and s-trans-acrylic acid in their ground vibrational states leading to precise determination of rotational, quartic and first complete set of sextic centrifugal distortion constants. New laboratory data of acrylic acid were then used to search for its spectral features in Orion KL, Sgr B2, and W51 molecular clouds. An upper limit to the column density of acrylic acid in Orion KL is provided.

  15. Well-defined iron complexes as efficient catalysts for "green" atom-transfer radical polymerization of styrene, methyl methacrylate, and butyl acrylate with low catalyst loadings and catalyst recycling.

    Science.gov (United States)

    Nakanishi, So-Ichiro; Kawamura, Mitsunobu; Kai, Hidetomo; Jin, Ren-Hua; Sunada, Yusuke; Nagashima, Hideo

    2014-05-05

    Environmentally friendly iron(II) catalysts for atom-transfer radical polymerization (ATRP) were synthesized by careful selection of the nitrogen substituents of N,N,N-trialkylated-1,4,9-triazacyclononane (R3 TACN) ligands. Two types of structures were confirmed by crystallography: "[(R3 TACN)FeX2 ]" complexes with relatively small R groups have ionic and dinuclear structures including a [(R3 TACN)Fe(μ-X)3 Fe(R3 TACN)](+) moiety, whereas those with more bulky R groups are neutral and mononuclear. The twelve [(R3 TACN)FeX2 ]n complexes that were synthesized were subjected to bulk ATRP of styrene, methyl methacrylate (MMA), and butyl acrylate (BA). Among the iron complexes examined, [{(cyclopentyl)3 TACN}FeBr2 ] (4 b) was the best catalyst for the well-controlled ATRP of all three monomers. This species allowed easy catalyst separation and recycling, a lowering of the catalyst concentration needed for the reaction, and the absence of additional reducing reagents. The lowest catalyst loading was accomplished in the ATRP of MMA with 4 b (59 ppm of Fe based on the charged monomer). Catalyst recycling in ATRP with low catalyst loadings was also successful. The ATRP of styrene with 4 b (117 ppm Fe atom) was followed by precipitation from methanol to give polystyrene that contained residual iron below the calculated detection limit (0.28 ppm). Mechanisms that involve equilibria between the multinuclear and mononuclear species were also examined. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. [Determination of 9 residual acrylic monomers in acrylic resins by gas chromatography-mass spectrometry coupled with microwave assisted extraction].

    Science.gov (United States)

    Lai, Ying; Lin, Rui; Cai, Luxin; Ge, Xiuxiu; Huang, Changchun

    2012-01-01

    A reliable gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 9 residual acrylic monomers (methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl acrylate, butyl methacrylate, styrene, acrylic acid and methacrylic acid) in acrylic resins. Solid resin was precipitated with methanol after microwave assisted extraction with ethyl acetate for 30 min, and liquid resin was diluted with methanol directly. The nine acrylic monomers got a good separation within 20 min on a DB-WAX column. The limits of quantification (LOQs, S/N = 10) of the method were in the range of 1-10 mg/kg for liquid resin and 3-50 mg/kg for solid resin. The calibration curves were linear within 1-500 mg/L range with correlation coefficients above 0. 995. The recoveries ranged from 84.4% to 108.6% at five spiked levels. The sensitivity, recovery and selectivity of the method can fully meet the requirements of practical work.

  17. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    Science.gov (United States)

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  18. Pluronic-poly (acrylic acid)-cysteine/Pluronic L121 mixed micelles improve the oral bioavailability of paclitaxel.

    Science.gov (United States)

    Zhao, Yanli; Li, Yanli; Ge, Jianjun; Li, Na; Li, Ling-Bing

    2014-11-01

    The aim of the study is to synthesize a thiolated Pluronic copolymer, Pluronic-poly (acrylic acid)-cysteine copolymer, to construct a mixed micelle system with the Pluronic-poly (acrylic acid)-cysteine copolymer and Pluronic L121 (PL121) and to evaluate the potential of these mixed micelles as an oral drug delivery system for paclitaxel. Compared with Pluronic-poly (acrylic acid)-cysteine micelles, drug-loading capacity of Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles was increased from 0.4 to 2.87%. In vitro release test indicated that Pluronic-poly (acrylic acid)-cysteine/PL121 mixed micelles exhibited a pH sensitivity. The permeability of drug-loaded micelles in the intestinal tract was studied with an in situ perfusion method in rats. The presence of verapamil and Pluronic both improved the intestinal permeability of paclitaxel, which further certified the inhibition effect of thiolated Pluronic on P-gp. In pharmacokinetic study, the area under the plasma concentration-time curve (AUC0→∞) of paclitaxel-loaded mixed micelles was four times greater than that of the paclitaxel solution (p acrylic acid)-cysteine/PL121 micelles were proven to be a potential oral drug delivery system for paclitaxel.

  19. Effect of porosity and environment on the mechanical behavior of acrylic bone cement modified with acrylonitrile-butadiene-styrene particles: part II. Fatigue crack propagation.

    Science.gov (United States)

    Vila, M M; Ginebra, M P; Gil, F J; Planell, J A

    1999-01-01

    The aim of this study was to investigate the effect of adding an elastomeric second phase, acrylonitrile-butadiene-styrene, on the fatigue crack propagation behavior of poly(methyl methacrylate) bone cement. Moreover, the influence of porosity and environmental conditions was studied. When comparing the plain cement to the modified cement, a decrease in the crack propagation rate was observed at between 1 and 2 orders of magnitude. The storage in a physiological environment (saline solution at 37 degrees C) also caused a decrease in the crack propagation rate of about 2 orders of magnitude for the plain and modified cement prepared in air or under a vacuum. Porosity did not have any noticeable effect on the fatigue crack propagation behavior of the cement.

  20. Gold Nanoparticles Protected with Thiol-Derivatized Amphiphilic Poly( -caprolactone)-b-poly(acrylic acid)

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Hvilsted, Søren

    2008-01-01

    Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid, subsequ......Amphiphilic poly(c-caprolactone)-b-poly(acrylic acid) (HS-PCL-b-PAA) bearing thiol functionality at the PCL terminal has been synthesized by a combination of ring-opening polymerization (ROP) of c-caprolactone (c-CL), esterification of hydroxy chain end with protected mercaptoacetic acid...... distribution (1.09). The hydroxy chain end of Br-PCL-OR was modified by reacting with a-(2,4-dinitrophenylthio)acetic acid or a-(4methoxytritylthio) acetic acid resulting in heterotelechelic PCL incorporating protected thiol and bromoester functionalities. It was then employed as macroinitiator in NiBr2(PPh3......)2 catalysed ATRP of tBA. ATRP of tBA provided diblock copolymers with low polydispersity index (1.17-1.39) while preserving the protected thiol function. Sequential or simultaneous removal of 2,4-dinitrophenyl or 4-methoxytrityl and tert-butyl ester groups resulted in HS-PCL-b-PAA. The PCL backbone remained...

  1. Bioinspired bioadhesive polymers: dopa-modified poly(acrylic acid) derivatives.

    Science.gov (United States)

    Laulicht, Bryan; Mancini, Alexis; Geman, Nathanael; Cho, Daniel; Estrellas, Kenneth; Furtado, Stacia; Hopson, Russell; Tripathi, Anubhav; Mathiowitz, Edith

    2012-11-01

    The one-step synthesis and characterization of novel bioinspired bioadhesive polymers that contain Dopa, implicated in the extremely adhesive byssal fibers of certain gastropods, is reported. The novel polymers consist of combinations of either of two polyanhydride backbones and one of three amino acids, phenylalanine, tyrosine, or Dopa, grafted as side chains. Dopa-grafted hydrophobic backbone polymers exhibit as much as 2.5 × the fracture strength and 2.8 × the tensile work of bioadhesion of a commercially available poly(acrylic acid) derivative as tested on live, excised, rat intestinal tissue. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Styrene maleic acid encapsulated raloxifene micelles for management of inflammatory bowel disease.

    Science.gov (United States)

    Greish, Khaled; Taha, Safa; Jasim, Anfal; Elghany, Sara Abd; Sultan, Ameera; AlKhateeb, Ali; Othman, Manal; Jun, Fang; Taurin, Sebastien; Bakhiet, Moiz

    2017-12-01

    Inflammatory bowel disease (IBD) comprises a group of disorders that manifest through chronic inflammation of the colon and small intestine. Although the exact cause of IBD is still unclear, dysfunctional immunoregulation involving overproduction of inflammatory cytokines such as TNF-α, and IL-6 have been implicated in pathogenesis. Current therapy relies on immunosuppression, cytotoxic drugs, and monoclonal antibodies against TNF-α. These classes of drugs have severe side-effects, especially when used for long duration. Our previous work with raloxifene, a selective estrogen receptor modulator, has shown that the drug, and to a greater extent its micellar formulation, has a significant suppressive effect on NF-κB, an essential immune-regulator. This finding directed the current work towards testing the anti-inflammatory and immunomodulatory effects of raloxifene using cell lines, as well as testing the potential use of the styrene maleic acid (SMA) micelles loaded with raloxifene (SMA-Ral) against dextran sulfate sodium (DSS) induced colitis in an in vivo model of IBD. Treatment of MCF-7 cells with TNF-α was shown to protect the cells from the cytotoxic effect of raloxifene (42 vs. 10% cell death, with TNF-α. Treating CaCo-2 cells with both free and SMA-Ral improved cell survival after exposure to 2% DDS with significantly higher protection with SMA-Ral. Treatment of U-937 with SMA-Ral and free-Ral resulted in down-regulation of TNF-α, IL-1β, IL-6, and MIP1α, with greater inhibition of the SMA-Ral, compared to free Ral. Balb/c mice treated with raloxifene and SMA-Ral showed weight gain at 14 days, compared to the control group (122, and 115% respectively). Treatment with raloxifene prevented DSS-induced diarrhea in 6/6 of free raloxifene treated mice and in 5/6 mice treated with SMA-Ral. Control group of DSS-treated mice showed average colon length of 7.4 cm compared to 13 cm in the control group. The average colon length was 12.3 and 11.5 cm for

  3. Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid-chitosan

    Directory of Open Access Journals (Sweden)

    Hortensia Ortega-Ortiz

    2010-06-01

    Full Text Available The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid.A atividade antimicrobiana de quitosana e complexos interpolieletrolíticos hidrossoluvéis de poli(ácido acrílico-quitosana foi estudada. Quitosanas de dois diferentes pesos moleculares foram testados em diferentes concentrações, 0,5 a 5 g • L-1, como agentes antimicrobianos nas P. aeruginosa e P. oleovorans. Em ambos os casos, obteu-se a melhor inibição microbiana com a concentração de 5 g • L-1, no entanto os complexos interpolieletrolíticos de poli (ácido acrílico-quitosana com composição φ = 2 apresentaram maior atividade antibacteriana do que os dois quitosans na concentração de 0,5 g • L-1. O complexo NPEC2 foi mais eficaz do que as quitosanas, sendo que o resultado pode ser atribuído ao número de moles dos grupos aminos da quitosana e aos grupos carboxílicos dos complexos de poli(ácido acrílico.

  4. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Hongzhu Liu

    2017-01-01

    Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  5. Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid.

    Science.gov (United States)

    Liu, Hongzhu; Bian, Jiming; Wang, Zhonggang; Hou, Chuan-Jin

    2017-01-22

    Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), n-butyl acrylate (BA), Veova 10, and acrylic acid (AA). The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV) accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

  6. Depletion of abundant plasma proteins by poly(N-isopropylacrylamide-acrylic acid) hydrogel particles

    DEFF Research Database (Denmark)

    Such-Sanmartín, Gerard; Ventura-Espejo, Estela; Jensen, Ole N

    2014-01-01

    the application of pH-sensitive poly(N-isopropylacrylamide-acrylic acid) hydrogel particles for removal of abundant plasma proteins, prior to proteome analysis by MS. Protein depletion occurs by two separate mechanisms: (1) hydrogel particles incubated with low concentrations of plasma capture abundant proteins...... at higher efficiency than low abundance proteins, which are enriched in the supernatants, whereas (2) hydrogel particles incubated with high concentrations of plasma capture and irreversibly trap abundant proteins. During the elution step, irreversibly trapped proteins remain captured while low abundance...... (SRM) liquid chromatography (LC)-MS/MS. This novel use of hydrogel particles opens new perspectives for biomarker analysis based on mass spectrometry....

  7. Synthesis of poly(N-isopropylacrylamide-co-acrylic acid) model compounds for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens; Christensen, Morten Lykkegaard; Scales, Peter

    2005-01-01

    is investigated by titration, differential scanning calorimetry (DSC) and capillary rheometry. The titration experiments indicates that the polymerization is a block copolymerization and the DSC result show that the blocks of poly(N-isopropylacrylamide) are not randomly distributed in the microgels. Capillary...... concentrations of acrylic acid as co-monomer. The microgels have a charge density between 0.2 and 0.9 mmol/g.   Preliminary filtration experiments show that filtration properties of the microgel model system significantly differs from the properties for inorganic colloidals such as titaniumdioxid....

  8. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Science.gov (United States)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won; Lim, Yun Kyong; Kook, Joong-Ki; Cho, Dong-Lyun; Kim, Byung Hoon

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH2 of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  9. Characterization of bioactive RGD peptide immobilized onto poly(acrylic acid) thin films by plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyun Suk; Ko, Yeong Mu; Shim, Jae Won [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of); Lim, Yun Kyong; Kook, Joong-Ki [Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju (Korea, Republic of); Cho, Dong-Lyun [School of Applied Chemical Engineering and Center for Functional Nano Fine Chemicals, Chonnam National University, Gwangju (Korea, Republic of); Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, Gwangju (Korea, Republic of)

    2010-11-01

    Plasma surface modification can be used to improve the surface properties of commercial pure Ti by creating functional groups to produce bioactive materials with different surface topography. In this study, a titanium surface was modified with acrylic acid (AA) using a plasma treatment and immobilized with bioactive arginine-glycine-aspartic acid (RGD) peptide, which may accelerate the tissue integration of bone implants. Both terminals containing the -NH{sub 2} of RGD peptide sequence and -COOH of poly(acrylic acid) (PAA) thin film were combined with a covalent bond in the presence of 1-ethyl-3-3-dimethylaminopropyl carbodiimide (EDC). The chemical structure and morphology of AA film and RGD immobilized surface were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). All chemical analysis showed full coverage of the Ti substrate with the PAA thin film containing COOH groups and the RGD peptide. The MC3T3-E1 cells were cultured on each specimen, and the cell alkaline phosphatase (ALP) activity were examined. The surface-immobilized RGD peptide has a significantly increased the ALP activity of MC3T3-E1 cells. These results suggest that the RGD peptide immobilization on the titanium surface has an effect on osteoblastic differentiation of MC3T3-E1 cells and potential use in osteo-conductive bone implants.

  10. Preparation and characterization of polyacrylamide-modified kaolinite containing poly [acrylic acid-co-methylene bisacrylamide] nanocomposite hydrogels

    DEFF Research Database (Denmark)

    Zaharia, Anamaria; Sarbu, Andrei; Radu, Anita-Laura

    2015-01-01

    Novel nanocomposite hydrogel structures based on cross-linked poly(acrylic acid) (PAA) and kaolinite (Kaol), modified with different loadings of polyacrylamide (PAAm), were prepared by inverse dispersion polymerization. Ceric ammonium nitrate as an initiator in the presence of nitric acid was used...

  11. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Luo, Shi-Zhong [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Wang, Bin, E-mail: bin_wang@scu.edu.cn [College of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Guo, ZhanHu [Chemical and Biomolecular Engineering Department, University of Tennessee, Knoxville, TN 37996 (United States)

    2015-08-01

    Highlights: • Small molecular weight poly(acrylic acid) incorporated on γ-alumina. • PAA adsorbed primarily on outer surface of alumina at low pH. • PAA infiltrated inside alumina pore at high pH. • Polymer chain reptation motion during the infiltration. - Abstract: The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (M{sub W} 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption–desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  12. Poly(acrylic acid) modifying bentonite with in-situ polymerization for removing lead ions.

    Science.gov (United States)

    He, Y F; Zhang, L; Yan, D Z; Liu, S L; Wang, H; Li, H R; Wang, R M

    2012-01-01

    In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5-60 min), initial concentration of metal ions (200-1,000 mg/L) and adsorbent dosage (0.04-0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).

  13. Controlled release of anti-diabetic drug Gliclazide from poly(caprolactone)/poly(acrylic acid) hydrogels.

    Science.gov (United States)

    Bajpai, S K; Chand, Navin; Soni, Shweta

    2015-01-01

    Drug Gliclazide (Glz) has limited solubility and low bioavailability. In order to obtain a controlled release of this drug and to improve its bioavailability, the drug has been loaded into poly(caprolactone) (PCL)/poly(acrylic acid) (PAAc) hydrogels, prepared by free radical polymerization of acrylic acid in the presence of poly(caprolactone) in acetone medium using azo-isobutyronitrile as initiator and N,N' methylene bisacrylamide as cross-linking agent. The swelling behaviour of these hydrogels has been investigated in the physiological gastric and intestinal fluids to obtain an optimum composition suitable for delivery of a biologically active compound. The gels were loaded with anti-diabetic drug Glz and a detailed investigation of release of drug has been carried out. Various kinetic models have been applied on the release data. Finally, the Albino wistar rats were treated for Streptozotocin plus nicotinamide - induced diabetes using a Glz-loaded PCL/PAAc hydrogel. The results indicated a fair reduction in the glucose level of rats.

  14. Acrylic Acid Improved Nylon 66 Fabric by Electron Beam Irradiation-induced Grafting

    Directory of Open Access Journals (Sweden)

    SANG Wei

    2017-10-01

    Full Text Available Acrylic acid was grafted onto nylon 66 fabric by the electron beam irradiation method. Effects of different grafting conditions on grafting reaction were investigated. Fourier transform infrared spectroscopy(FTIR, thermo gravimetric analyzer(TGA, scanning electron microscope(SEM and YG065 type fabric strength tester were used to characterize the chemical structures, thermal properties, surface morphology and mechanical properties of these prepared nylon 66 fabric samples. And the anti-dripping performance was evaluated by the vertical burning. The results show that in FTIR spectrum new absorption peeks at 1720.2 cm-1 and other wave numbers are assigned to the carboxyl groups, which imply that acrylic acid is successfully grafted to the nylon 66 molecular. The anti-dripping performance of nylon 66 fabric is improved significantly after grafting. It can be attributed to the cross-linked char layer which subsequently provides a support for the melting fiber. However, the mechanical properties of grafted samples decrease to some extent. With the increase of grafting ratio, the onset temperatures of grafted samples decrease gradually, while the char-forming performance enhances significantly. Besides, the damage length and droplet velocity of grafted samples become shorter and lower, and the tensile strength at break increases slightly.

  15. Accurate determination of residual acrylic acid in superabsorbent polymer of hygiene products by headspace gas chromatography.

    Science.gov (United States)

    Zhang, Shu-Xin; Chai, Xin-Sheng; Jiang, Ran

    2017-02-17

    This work reports on a method for the determination of residual acrylic acid (AA) in the superabsorbent polymers for hygiene products by headspace analysis. It was based on water extraction for the polymer sample at a room temperature for 50min. Then, the AA in the extractant reacted with bicarbonate solution in a closed headspace sample vial, from which the carbon dioxide generated from the reaction (within 20min at 70°C) was detected by gas chromatography (GC). It was found that there is adsorption partition equilibrium of AA between solid-liquid phases. Therefore, an equation for calculating the total AA content in the original polymers sample was derived based on the above phase equilibrium. The results show that the HS-GC method has good precision (RSD<2.51%) and good accuracy (recoveries from 93 to 105%); the limit of quantification (LOQ) was 373mg/kg. The present method is rapid, accurate, and suitable for determining total residual acrylic acid in a wide variety of applications from processing of superabsorbent polymer to commercial products quality control. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Potassium fulvate-modified graft copolymer of acrylic acid onto cellulose as efficient chelating polymeric sorbent.

    Science.gov (United States)

    Mohamed, Magdy F; Essawy, Hisham A; Ammar, Nabila S; Ibrahim, Hanan S

    2017-01-01

    Acrylic acid (AA) was graft copolymerized from cellulose (Cell) in presence of potassium fulvate (KF) in order to enhance the chemical activity of the resulting chelating polymer and the handling as well. Fourier transform infrared (FTIR) proved that KF was efficiently inserted and became a permanent part of the network structure of the sorbent in parallel during the grafting copolymerization. Scanning electron microscopy (SEM) revealed intact homogeneous structure with uniform surface. This indicates improvement of the handling, however, it was not the case for the graft copolymer of acrylic acid onto cellulose in absence of KF, which is known to be brittle and lacks mechanical integrity. Effective insertion of this co-interpenetrating agent provided more functional groups, such as OH and COOH, which improved the chelating power of the produced sorbent as found for the removal of Cu(2+) ions from its aqueous solutions (the removal efficiency reached ∼98.9%). Different models were used to express the experimental data. The results corroborated conformity of the pseudo-second order kinetic model and Langmuir isotherm model to the sorption process, which translates into dominance of the chemisorption. Regeneration of the chelating polymers under harsh conditions did not affect the efficiency of copper ions uptake up to three successive cycles. A thermodynamic investigation ensured exothermic nature of the adsorption process that became less favourable at higher temperatures. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Superhydrophobic surface fabricated by bulk photografting of acrylic acid onto high-density polyethylene.

    Science.gov (United States)

    Han, Jianmei; Wang, Xiaoxiao; Wang, Huiliang

    2008-10-15

    A superhydrophobic polymeric surface was prepared through a very simple bulk photografting method. A thin layer of acrylic acid (AA), a highly hydrophilic monomer, was sandwiched between two high-density polyethylene (HDPE) sheets, followed by UV irradiation for a short time, and then the two sheets were pulled apart and dried. The contact angles on the two grafted surfaces decreased very quickly with irradiation time in the first several seconds, and then increased with irradiation time to a level higher than that on pristine HDPE surface. When using a scraped PE surface as the bottom one, it showed superhydrophobicity after 35 s irradiation. XPS investigations show that strong rearrangement of the poly(acrylic acid) molecules has taken place on both surfaces, especially on the bottom surface, which provides the low surface free energy. The scraping and the grafting process led to the formation a unique micro- and nanostructure on the surface. These two factors lead to the superhydrophobicity. The as-prepared surface possesses superhydrophobic properties in a wide range of pH values, stimuli-responsive properties and low or very high adhesion under different situations.

  18. Preparation of Caco-2 cell sheets using plasma polymerised acrylic acid as a weak boundary layer.

    Science.gov (United States)

    Majani, Ruby; Zelzer, Mischa; Gadegaard, Nikolaj; Rose, Felicity R; Alexander, Morgan R

    2010-09-01

    The use of cell sheets for tissue engineering applications has considerable advantages over single cell seeding techniques. So far, only thermoresponsive surfaces have been used to manufacture cell sheets without chemically disrupting the cell-surface interactions. Here, we present a new and facile technique to prepare sheets of epithelial cells using plasma polymerised acrylic acid films. The cell sheets are harvested by gentle agitation of the media without the need of any additional external stimulus. We demonstrate that the plasma polymer deposition conditions affect the viability and metabolic activity of the cells in the sheet and relate these effects to the different surface properties of the plasma polymerised acrylic acid films. Based on surface analysis data, a first attempt is made to explain the mechanism behind the cell sheet formation. The advantage of the epithelial cell sheets generated here over single cell suspensions to seed a PLGA scaffold is presented. The scaffold itself, prepared using a mould fabricated via photolithography, exhibits a unique architecture that mimics closely the dimensions of the native tissue (mouse intestine). Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Polyurethane modification with acrylic acid by Ce(IV-initiated graft polymerization

    Directory of Open Access Journals (Sweden)

    Butruk-Raszeja Beata A.

    2016-01-01

    Full Text Available This paper presents a method for polyurethane surface functionalization for tissue engineering applications. Functionalization has been carried out by grafting acrylic acid to the polyurethane surface with the use of radical polymerization with a Ce4+ initiator. Contrary to other papers suggesting that the presence of hydroxyl groups are essential for successful grafting via ceric ions, we propose a method with the omission of the surface hydroxylation step. The influence of reaction conditions: reaction time, reaction temperature and monomer concentration on carboxyl groups surface density has been analyzed and described. The quantity of carboxyl groups on the surface was determined with the use of the TBO method. Materials grafted with acrylic acid have been subjected to conjugation with a peptide using sulfoNHS/ EDC chemistry. Successful incorporation of the peptide has been confirmed by an ELISA assay. Additionally, for better characterization, after each step of modification materials were subjected to SEM, FTIR-ATR, XPS and contact angle measurement analysis.

  20. Gallium-modified chitosan/poly(acrylic acid) bilayer coatings for improved titanium implant performances.

    Science.gov (United States)

    Bonifacio, Maria A; Cometa, Stefania; Dicarlo, Manuela; Baruzzi, Federico; de Candia, Silvia; Gloria, Antonio; Giangregorio, Maria M; Mattioli-Belmonte, Monica; De Giglio, Elvira

    2017-06-15

    A gallium-modified chitosan/poly(acrylic acid) bilayer was obtained by electrochemical techniques on titanium to reduce orthopaedic and/or dental implants failure. The bilayer in vitro antibacterial properties and biocompatibility were evaluated against Escherichia coli and Pseudomonas aeruginosa and on MG63 osteoblast-like cells, respectively. Gallium loading into the bilayer was carefully tuned by the electrochemical deposition time to ensure the best balance between antibacterial activity and cytocompatibility. The 30min deposition time was able to reduce in vitro the viable cell counts of E. coli and P. aeruginosa of 2 and 3 log cfu/sheet, respectively. Our results evidenced that the developed antibacterial coating did not considerably alter the mechanical flexural properties of titanium substrates and, in addition, influenced positively MG63 adhesion and proliferation. Therefore, the gallium-modified chitosan/poly(acrylic acid) bilayer can be exploited as a promising titanium coating to limit bacterial adhesion and proliferation, while maintaining osseointegrative potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. CHARACTERISTIC OF ACRYLIC ACID GRAFTED POLYETHYLENE FILM PREPARED BY GAMMA IRRADIATION METHOD

    Directory of Open Access Journals (Sweden)

    John Hendri

    2010-06-01

    Full Text Available In this study, high density polyethylene (PE film (thickness 80 μm was modified by grafting of acrylic acid (AA onto the film using 15 kGy of g irradiation as initiator, applied at different exposure times. In addition to irradiation dose, other variables investigated are concentration of AA, the type of solvent, and polymerization time carried out at 60 oC. The success of the graft copolymerization processes was confirmed by analysing the grafted film using FTIR spectroscopy, which revealed the existence of absorption band at wave number of 1721 cm-1 (assigned to C=O, and that at 3385 cm-1 (assigned to -OH, and the physical endurance of the sample was evaluated by carrying out tensile strength measurement. The percent of grafting was determined according to the gravimetric method. The results indicated that the highest percent of grafting was obtained by application of 2-hour irradiation time, with monomer concentration of 30 % in water as a solvent, grafting temperature of 60 oC. Activity of grafted was evaluated by measurement of the absorption capacity toward water and Cu2+ ion, and revealed the increase of the absorption capacity with increased percent of grafting.   Keywords: Graft copolymerization, acrylic acid, low density polyethylene, gamma irradiation, water absorbency, absorption of cupric ion

  2. In Situ Nitroxide-Mediated Polymerized Poly(acrylic acid as a Stabilizer/Compatibilizer Carbon Nanotube/Polymer Composites

    Directory of Open Access Journals (Sweden)

    Vitaliy Datsyuk

    2007-01-01

    the opportunity to reinitiate the polymerization of a second block that can be chosen among a wide range of monomers. This versatility is illustrated with a second block containing methyl acrylate (MA or styrene (S. Scanning and transmission electron microscopies confirm good CNT dispersion in the polymer network, while transmission electron microscopy also spots the anchorage locations of PAA on the CNT surface. Such nanotubes wrapped by diblock copolymers can be dispersed in various polymer matrices to create CNT—polymer composites. Conductivity measurements show that these composites obey a percolation-like power law with a low percolation threshold (less than 0.5 vol% and a high maximum conductivity (up to 1.5 S/cm at room temperature.

  3. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes

    NARCIS (Netherlands)

    Swainsbury, David J. K.; Scheidelaar, Stefan; Foster, Nicholas; van Grondelle, Rienk; Killian, J. Antoinette; Jones, Michael R.

    2017-01-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such as styrene maleic acid (SMA) for the solubilisation, purification and

  4. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    OpenAIRE

    Liangming Wei; Changxin Chen; Zhongyu Hou; Hao Wei

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dim...

  5. Engineering Escherichia coli with acrylate pathway genes for propionic acid synthesis and its impact on mixed-acid fermentation.

    Science.gov (United States)

    Kandasamy, Vijayalakshmi; Vaidyanathan, Hema; Djurdjevic, Ivana; Jayamani, Elamparithi; Ramachandran, K B; Buckel, Wolfgang; Jayaraman, Guhan; Ramalingam, Subramanian

    2013-02-01

    Fermentation-derived products are in greater demand to meet the increasing global market as well as to overcome environmental problems. In this work, Escherichia coli has been metabolically engineered with acrylate pathway genes from Clostridium propionicum for the conversion of D-lactic acid to propionic acid. The introduced synthetic pathway consisted of seven genes encoding the enzymes propionate CoA-transferase (Pct), lactoyl-CoA dehydratase (Lcd) and acryloyl-CoA reductase (Acr). The engineered strain synthesised propionic acid at a concentration of 3.7 ± 0.2 mM upon fermentation on glucose. This low production level could be attributed to the low activity of the recombinant enzymes in particular the rate-limiting enzyme, Acr. Interestingly, the recombinant pathway caused an increased lactate production in E. coli with a yield of 1.9 mol/mol of glucose consumed along with a decrease in other by-products. Down-regulation of the pfl (pyruvate formate lyase) genes and a possible inhibition of Pfl activity by the acrylate pathway intermediate, acryloyl-CoA, could have reduced carbon flow to the Pfl pathway with a concomitant increase in lactate production. This study reports a novel way of synthesising propionic acid by employing a non-native, user-friendly organism through metabolic engineering.

  6. THE USE OF CHLOROSULFONIC ACID ON SULFONATION OF cPTFE FILM GRAFTED STYRENE FOR PROTON EXCHANGE MEMBRANE

    Directory of Open Access Journals (Sweden)

    Yohan Yohan

    2010-06-01

    Full Text Available Sulfonation of g-ray iradiated and styrene-grafted crosslinked polytetrafluoro ethylene film (cPTFE-g-S film have been done. The aim of the research was to make hydrophyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared by using chlorosulfonic acid in chloroethane under various conditions. The impact of the percentage of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film were examined. The results show that sulfonation of surface-grafted films was incomplete at room temperature. Increasing concentration of chlorosulfonic acid and reaction temperature accelerate the reaction but they also favor side reactions. These lead to the decrease of the ion-exchange capacity, water uptake, and proton conductivity but the increase of the resistance to oxidation in a perhydrol solution. The resulted cPTFE-g-SS membraneis stabile in a H2O2 30% solution for 20 h.   Keywords: Chorosulfonic acid, sulfonation, PTFE film, proton excange membrane.

  7. The copolimeryzation synthesis and swelling capacity of cellulose-poly superabsorbent (acrylic acid-co-acrylamide) based on rice straw

    Science.gov (United States)

    Helmiyati; Fitriyani, A.; Meyanti, F.

    2017-04-01

    A superabsorbent has been synthesized by copolymerization of rice straw cellulose as the back bone with the composition of 0.724 mol/L acrylamide and 1.429 mol/L acrylic acid as the monomers, 2.32 mmol/L N, N‧-methylene-bis-acrylamide as the crosslinker, and 7.94 mmol/L potassium persulfate as the initiator. The rendement of cellulose obtained from rice straw isolation is 33.55% with the size of 34.06 nm nanocrystalline cellulose, obtained from XRD diffraction pattern. The copolymerization results in the spectrum characterization of Cellulose-Poly superabsorbent (AA-co-AM) with FTIR shows OH stretching vibration, NH and C=O stretching of monomer acrylic acid and acrylamide at wave number about 3343 cm-1 and 1600 cm-1. The surface morphology analyzed with SEM shows the superabsorbent has rough surface morphology compared to acrylic acid-acrylamide copolymer. The results of grafting efficiency increases with the increasing amount of the reacted monomer. The characterization of result shows that the grafting process of acrylic acid-acrylamide on cellulose has been formed. The swelling capacity of superabsorbent in water is 691.18 g/g, and 765.58 g/g in urea. This result is quite satisfactory and can be applied for slow release superabsorbent.

  8. Introduction of poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid)] branches onto starch for cotton warp sizing.

    Science.gov (United States)

    Shen, Shiqi; Zhu, Zhifeng; Liu, Fengdan

    2016-03-15

    An attempt has been made to reveal the effect of amphoteric poly(2-acryloyloxyethyl trimethyl ammonium chloride-co-acrylic acid) [P(ATAC-co-AA)] branches grafted onto the backbones of starch upon the adhesion-to-cotton, film properties, and desizability of maize starch for cotton warp sizing. Starch-g-poly[(2-acryloyloxyethyl trimethyl ammonium chloride)-co-(acrylic acid) [S-g-P(ATAC-co-AA)] was prepared by the graft copolymerization of 2-acryloyloxyethyl trimethyl ammonium chloride (ATAC) and acrylic acid (AA) with acid-converted starch (ACS) in aqueous medium using Fe(2+)-H2O2 initiator. The adhesion was evaluated in term of bonding strength according to the FZ/T 15001-2008 whereas the film properties considered included tensile strength, work and percentage elongation at break. The evaluation was undertaken through the comparison of S-g-P(ATAC-co-AA) with ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride). It was found that the amphoteric branch was able to significantly improve the adhesion and mitigate the brittleness of starch film. Zeta potential of cooked S-g-P(ATAC-co-AA) paste, depending on the mole ratio of ATAC to AA units on P(ATAC-co-AA) branches, had substantial effect on the adhesion and desizability. Increasing the mole ratio raised the potential, which favored the adhesion but disfavored the removal of S-g-P(ATAC-co-AA) from sized cotton warps. Electroneutral S-g-P(ATAC-co-AA) was superior to negatively grafted starch in adhesion and to positively grafted starch in desizability. Generally, it showed better sizing property than ACS, starch-g-poly(acrylic acid), and starch-g-poly(2-acryloyloxyethyl trimethyl ammonium chloride), and had potential in the application of cotton warp sizing. Copyright © 2015. Published by Elsevier Ltd.

  9. Michael-type addition of azoles of broad-scale acidity to methyl acrylate

    Directory of Open Access Journals (Sweden)

    Krzysztof Z. Walczak

    2011-02-01

    Full Text Available An optimisation of Michael-type addition of azole derivatives of broad-scale acidity – ranging from 5.20 to 15.00 pKa units – namely 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5-nitroimidazole, 5(4-bromo-2-methyl-4(5-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. The optimisation process involved the use of an appropriate basic catalyst (DBU, DIPEA, NaOH, NaH, TEDA, a donor/base/acceptor ratio and the reaction temperature. The reactions were performed in DMF as solvent. Target Michael adducts were obtained in medium to excellent yields. Importantly, for imidazole and 1,2,4-triazole derivatives, no corresponding regioisomers were obtained.

  10. Dyes adsorption using a synthetic carboxymethyl cellulose-acrylic acid adsorbent.

    Science.gov (United States)

    Zhang, Genlin; Yi, Lijuan; Deng, Hui; Sun, Ping

    2014-05-01

    Removal of noxious dyes is gaining public and technological attention. Herein grafting polymerization was employed to produce a novel adsorbent using acrylic acid and carboxymethyl cellulose for dye removal. Scanning electron microscopy and Fourier-transform infrared spectroscopy verified the adsorbent formed under optimized reaction conditions. The removal ratio of adsorbent to Methyl Orange, Disperse Blue 2BLN and malachite green chloride reached to 84.2%, 79.6% and 99.9%, respectively. The greater agreement between the calculated and experimental results suggested that pseudo second-order kinetic model better represents the kinetic adsorption data. Equilibrium adsorptions of dyes were better explained by the Temkin isotherm. The results implied that this new cellulose-based absorbent had the universality for removal of dyes through the chemical adsorption mechanism. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  11. Properties of the acrylic acid polymers obtained by atmospheric pressure plasma polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Topala, Ionut [Plasma Physics Laboratory, Faculty of Physics, Al. I. Cuza University, 11 Carol I Boulevard, 700506 Iasi (Romania)], E-mail: itopala@plasma.uaic.ro; Dumitrascu, Nicoleta; Popa, Gheorghe [Plasma Physics Laboratory, Faculty of Physics, Al. I. Cuza University, 11 Carol I Boulevard, 700506 Iasi (Romania)

    2009-01-15

    Plasma polymers of acrylic acid were obtained using an atmospheric pressure discharge system. The plasma polymerization reactor uses a dielectric barrier discharge, with the polyethylene terephthalate dielectric acting as substrate for deposition. The plasma was characterized by specific electrical measurements, monitoring the applied voltage and the discharge current. Based on the spatially resolved optical emission spectroscopy, we analyzed the distribution of the excited species in the discharge gap, specific plasma temperatures (vibrational and gas temperatures) being calculated with the Boltzmann plot method. The properties of the plasma polymer films were investigated by contact angle measurements, infrared and UV-Vis spectroscopy, scanning electron microscopy. The films produced by plasma polymerization at atmospheric pressure showed a hydrophilic character, in correlation with the strong absorbance of OH groups in the FTIR spectrum. Moreover, the surface of the plasma polymers at micrometric scale is smooth and free of defects without particular features.

  12. Poly(acrylic acid surface grafted polypropylene films: Near surface and bulk mechanical response

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Radical photo-grafting polymerization constitutes a promising technique for introducing functional groups onto surfaces of polypropylene films. According to their final use, surface grafting should be done without affecting overall mechanical properties. In this work the tensile drawing, fracture and biaxial impact response of biaxially oriented polypropylene commercial films grafted with poly(acrylic acid (PAA were investigated in terms of film orientation and surface modification. The variations of surface roughness, elastic modulus, hardness and resistance to permanent deformation induced by the chemical treatment were assessed by depth sensing indentation. As a consequence of chemical modification the optical, transport and wettability properties of the films were successfully varied. The introduced chains generated a PAA-grafted layer, which is stiffer and harder than the neat polypropylene surface. Regardless of the surface changes, it was proven that this kind of grafting procedure does not detriment bulk mechanical properties of the PP film.

  13. Design of psyllium-PVA-acrylic acid based novel hydrogels for use in antibiotic drug delivery.

    Science.gov (United States)

    Singh, Baljit; Sharma, Vikrant

    2010-04-15

    In order to exploit the potential of gel forming medicinally important polysaccharide, we have developed psyllium based hydrogels through graft copolymerization. The optimum conditions for the synthesis of psyllium-poly(vinyl alcohol) (PVA)-poly(acrylic acid) blended hydrogels have been evaluated and their characterization has been carried out by SEMs, FTIR and swelling studies. The optimum conditions for the synthesis of hydrogels have been obtained as 1% (v/v) acrylic acid, 2% (w/v) PVA and 1g of psyllium. The use of very small amount of these petroleum products has developed the low energy, cost effective, biodegradable and biocompatible material for potential biomedical applications. It is the novelty of the present finding. The release of model antibiotic drug tetracycline HCl from the hydrogels has been observed more in pH 2.2 buffer hence these hydrogels are suitable for peptic ulcer caused by Helicobacter pylori. At the same time psyllium has also been reported to cure the ulcerative colitis. Hence, the present drug delivery system will have double potential to cure ulcer. The values of the diffusion exponent for the release of drug have been obtained as (0.774, 0.576 and 0.858) and gel characteristic constant have been (8.884x10(-3), 24.149x10(-3) and 3.989x10(-3)) respectively in pH 2.2 buffer, 7.4 buffer and distilled water. The release of the drug from the hydrogels occurred through non-Fickian diffusion mechanism. Copyright 2010 Elsevier B.V. All rights reserved.

  14. [Electrokinetic chromatographic properties of amphiphilic copolymer poly (styrene-co-methacrylic acid) self-assembled micelle pseudostationary phase].

    Science.gov (United States)

    Ma, Xinyu; Ni, Xinjiong; Lu, Jie; Xing, Xiaoping; Cao, Yuhua; Cao, Guangqun

    2015-04-01

    The amphiphilic copolymer poly (styrene-co-methacrylic acid) (P (St-co-MAA)) with molar ratios of 6:4 and 7:3 self-assembled to form micelles. The polymeric micelles were used as pseudostationary phase (PSP) in micellar electrokinetic chromatography ( MEKC). Their physicochemical properties and MEKC performance were investigated as well in the present work. The critical micelle concentration ( CMC) , polarity, surface charge density and hydrodynamic diameter were used to characterize the solution physicochemical properties, while the methylene group selectivity was evaluated with n-alkylphenone homologous series. The time window and linear solvation energy relationship (LSER) analysis were used to characterize the MEKC retention behavior and the selectivity. All of these were compared with poly (methyl methacrylate-co-methacrylic acid) (P (MMA-co-MAA)) with the molar ratio of 7:3 and sodium dodecyl sulfate (SDS) micellar systems. The results showed that P ( St-co-MAA) system had the minimum CMC, the widest time window and the best methylene group selectivity. LSER analysis results showed that the hydrophobic effect was the most important interaction between solutes and PSPs, and the hydrogen-bonding acidity was the second significant factor on selectivity and MEKC retention behavior. P (St-co-MAA) system, especially with the molar ratio of 7 :3, had the highest effective parameter in LSER and showed a high separation selectivity of PSP.

  15. SPECTROSCOPIC STUDY ON POLY(ACRYLIC ACID-CO-ACRYLAMIDE)-GRAFT-POLYANILINE AS A RADIATION DOSIMETER FOR ALPHA PARTICLES.

    Science.gov (United States)

    Abd El-Mageed, H R; Abd El-Salam, H M; Eissa, M F

    2017-08-31

    Poly(acrylate-co-acrylamide) was a synthesis by chemical oxidation polymerization of an aqueous binary mixture of acrylate/acrylamide (1:1 mole ratio) using ammonium persulphate as an initiator at 70°C under the nitrogen atmosphere. The obtained copolymer was introduced for grafting with polyaniline. The grafting process was performed by chemical oxidation polymerization of aniline using ammonium persulphate as an initiator in hydrochloric acid media at 40°C under the nitrogen atmosphere. Poly(acrylic acid-co-acrylamide)-graft-polyaniline samples irradiated with (alpha-particles) at different irradiation doses (0, 2.33, 8.73, 13.09 and 17.46 Gy) at the same linear energy transfer. The change in the morphology, optical properties and the energy gap of poly(acrylic acid-co-acrylamide)-graft-polyaniline samples were studied. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. One-step formation of multiple Pickering emulsions stabilized by self-assembled poly(dodecyl acrylate-co-acrylic acid) nanoparticles.

    Science.gov (United States)

    Zhu, Ye; Sun, Jianhua; Yi, Chenglin; Wei, Wei; Liu, Xiaoya

    2016-09-13

    In this study, a one-step generation of stable multiple Pickering emulsions using pH-responsive polymeric nanoparticles as the only emulsifier was reported. The polymeric nanoparticles were self-assembled from an amphiphilic random copolymer poly(dodecyl acrylate-co-acrylic acid) (PDAA), and the effect of the copolymer content on the size and morphology of PDAA nanoparticles was determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The emulsification study of PDAA nanoparticles revealed that multiple Pickering emulsions could be generated through a one-step phase inversion process by using PDAA nanoparticles as the stabilizer. Moreover, the emulsification performance of PDAA nanoparticles at different pH values demonstrated that multiple emulsions with long-time stability could only be stabilized by PDAA nanoparticles at pH 5.5, indicating that the surface wettability of PDAA nanoparticles plays a crucial role in determining the type and stability of the prepared Pickering emulsions. Additionally, the polarity of oil does not affect the emulsification performance of PDAA nanoparticles, and a wide range of oils could be used as the oil phase to prepare multiple emulsions. These results demonstrated that multiple Pickering emulsions could be generated via the one-step emulsification process using self-assembled polymeric nanoparticles as the stabilizer, and the prepared multiple emulsions have promising potential to be applied in the cosmetic, medical, and food industries.

  17. Production of acrylic acid and propionic acid by constructing a portion of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula in Escherichia coli.

    Science.gov (United States)

    Liu, Zhijie; Liu, Tiangang

    2016-12-01

    Acrylic acid and propionic acid are important chemicals requiring affordable, renewable production solutions. Here, we metabolically engineered Escherichia coli with genes encoding components of the 3-hydroxypropionate/4-hydroxybutyrate cycle from Metallosphaera sedula for conversion of glucose to acrylic and propionic acids. To construct an acrylic acid-producing pathway in E. coli, heterologous expression of malonyl-CoA reductase (MCR), malonate semialdehyde reductase (MSR), 3-hydroxypropionyl-CoA synthetase (3HPCS), and 3-hydroxypropionyl-CoA dehydratase (3HPCD) from M. sedula was accompanied by overexpression of succinyl-CoA synthetase (SCS) from E. coli. The engineered strain produced 13.28 ± 0.12 mg/L of acrylic acid. To construct a propionic acid-producing pathway, the same five genes were expressed, with the addition of M. sedula acryloyl-CoA reductase (ACR). The engineered strain produced 1430 ± 30 mg/L of propionic acid. This approach can be expanded to synthesize many important organic chemicals, creating new opportunities for the production of chemicals by carbon dioxide fixation.

  18. Esterification from derivates of styrene by acetic acid using perchloric acid as a catalyzer; Esterificacion de derivados de estireno con acido acetico en presencia de acido perclorico como catalizador

    Energy Technology Data Exchange (ETDEWEB)

    Martinez de la Cuesta, P.J.; Rus Martinez, E.; Palomino sosa, R.; Palomino Perez, F. I. [Departamento deIngenieria Quimica, Facultad de Ciencias, Universidad de Malaga, Malaga (Spain)

    1995-11-01

    The present work is focused to develop the production of esters from derivatives of styrene by acetic acid using perchloric acid as a catalyst. The kinetics of the reaction was studied and analysis of the variables was carried out. 18 refs.

  19. Nanocapsule of cationic liposomes obtained using "in situ" acrylic acid polymerization: stability, surface charge and biocompatibility.

    Science.gov (United States)

    Scarioti, Giovana Danieli; Lubambo, Adriana; Feitosa, Judith P A; Sierakowski, Maria Rita; Bresolin, Tania M B; de Freitas, Rilton Alves

    2011-10-15

    In this work, didecyldimethylammonium bromide (DDAB) and 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) (2.5:1) were used to prepare liposomes coated with polyacrylic acid (PAA) using "in situ" polymerization with 2.5, 5 and 25 mM of acrylic acid (AA). The PAA concentrations were chosen to achieve partially to fully covered capsules, and the polymerization reaction was observed with real-time monitoring using dynamic light scattering (NanoDLS). The DDAB:DOPE liposomes showed stability in the tested temperature range (25-70°C), whereas the results confirmed the success of the polymerization according to superficial charge (zeta potential of +66.7±1.2 mV) results and AFM images. For the liposomes that were fully coated with PAA (zeta potential of +0.3±3.9 mV), cytotoxicity was independent of the concentration of albumin. Cationic liposomes and nanocapsules of the stable liposomes coated with PAA were obtained by controlling the surface charge, which was the most important factor related to cytotoxicity. Thus, a potential, safe drug nanocarrier was successfully developed in this work. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Ultra-Thin Films of Poly(acrylic acid/Silver Nanocomposite Coatings for Antimicrobial Applications

    Directory of Open Access Journals (Sweden)

    Alaa Fahmy

    2016-01-01

    Full Text Available In this work not only colloids of poly(acrylic acid (PAA embedded with silver nanoparticles (Ag-NPs but thin films (10 nm also were deposited using electrospray deposition technique (ESD. A mixture of sodium borohydride (NaBH4 and ascorbic acid (AA were utilized to reduce the silver ions to generate Ag-NPs in the PAA matrix. Moreover, sodium tricitrate was used to stabilize the prepared colloids. The obtained colloids and films were characterized using UV-visible, transmission electron microscopy (TEM. UV-Vis results reveal that an absorption peak at 425 nm was observed in presence of PAA-AgNO3-AA-citrate-NaBH4. This peak is attributed to the well-known surface plasmon resonance of the silver bound in Ag-NPs, while the reduction was rendering and/or inhibiting in absence of the AA and citrate. FTIR spectroscopy was used to study the mechanism of the reaction process of silver nitrate with PAA. TEM images showed the well dispersion of Ag-NPs in the PAA matrix with average particle size of 8 nm. The antimicrobial studies showed that the Ag-NPs embedded in the PAA matrix have proven to have a significant antimicrobial activity against E. coli, B. subtilis, and C. albicans.

  1. Synthesis of poly acrylic acid modified silver nanoparticles and their antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Zhihui [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Wang, Zhihua [Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004 (China); Sun, Lei, E-mail: sunlei@henu.edu.cn [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie [Key Laboratory of Cellular and Molecular Immunology, Henan University, Kaifeng 475004 (China); Zhao, Yanbao [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2014-08-01

    Poly acrylic acid modified silver (Ag/PAA) nanoparticles (NPs) have been successfully synthesized in the aqueous solution by using tannic acid as a reductant. The structure, morphology and composition of Ag/PAA NPs were characterized by various techniques such as X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible absorption spectroscopy (UV–vis) and thermogravimetry analysis (TGA). The results show that PAA/Ag NPs have a quasi-ball shape with an average diameter of 10 nm and exhibit well crystalline, and the reaction conditions have some effect on products morphology and size distribution. In addition, the as-synthesized Ag/PAA NPs antimicrobial activities against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) were evaluated by the methods of broth dilution, cup diffusion, optical density (OD600) and electron microscopy observation. The as-synthesized Ag/PAA NPs exhibit excellent antibacterial activity. The antimicrobial mechanism may be attributed to the damaging of bacterial cell membrane and causing leakage of cytoplasm. - Highlights: • Dispersed Ag/PAA NPs with small size were synthesized. • Ag/PAA NPs exhibited excellent antimicrobial properties. • Interaction mechanism between Ag/PAA NPs and bacteria was verified.

  2. Homo- and co-polymerization of polysytrene-block-poly(acrylic acid)-coated metal nanoparticles.

    Science.gov (United States)

    Wang, Hong; Song, Xiaohui; Liu, Cuicui; He, Jiating; Chong, Wen Han; Chen, Hongyu

    2014-08-26

    Amphiphilic block copolymers such as polystyrene-block-poly(acrylic acid) (PSPAA) give micelles that are known to undergo sphere-to-cylinder shape transformation. Exploiting this polymer property, core-shell nanoparticles coated in PSPAA can be "polymerized" into long chains following the chain-growth polymerization mode. This method is now extended to include a variety of different nanoparticles. A case study on the assembly process was carried out to understand the influence of the PAA block length, the surface ligand, and the size and morphology of the monomer nanoparticles. Shortening the PAA block promotes the reorganization of the amphiphilic copolymer in the micelles, which is essential for assembling large Au nanoparticles. Small Au nanoparticles can be directly "copolymerized" with empty PSPAA micelles into chains. The reaction time, acid quantity, and the [Au nanoparticles]/[PSPAA micelles] concentration ratio played important roles in controlling the sphere-cylinder-vesicle conversion of the PSPAA micelles, giving rise to different kinds of random "copolymers". With this knowledge, a general method is then developed to synthesize homo, random, and block "copolymers", where the basic units include small Au nanoparticles (d = 16 nm), large Au nanoparticles (d = 32 nm), Au nanorods, Te nanowires, and carbon nanotubes. Given the lack of means for assembling nanoparticles, advancing synthetic capabilities is of crucial importance. Our work provides convenient routes for combining nanoparticles into long-chain structures, facilitating rational design of complex nanostructures in the future.

  3. Electrical, dielectric and electrochemical characterization of novel poly(acrylic acid)-based polymer electrolytes complexed with lithium tetrafluoroborate

    Science.gov (United States)

    Ngai, Koh Sing; Ramesh, S.; Ramesh, K.; Juan, Joon Ching

    2018-01-01

    A series of novel poly(acrylic acid)-based polymer electrolytes with high conductivities at room temperature has been prepared and studied. Polymer electrolytes composed of poly(acrylic acid) (PAA) and lithium tetrafluoroborate (LiBF4) were prepared by means of solution casting. The effect of the addition of LiBF4 on the properties of the PAA-based electrolyte matrices was analysed and investigated using impedance spectroscopy. The optimized PAA-based solid electrolyte showed an electrochemical stability window of 3.2 V. Thermogravimetric analysis indicated that the incorporation of LiBF4 into PAA matrix enhances the thermal stability. The structural properties of polymer electrolytes were studied by using X-ray diffraction analysis.

  4. Synthesis, characterization, and swelling behaviors of salt-sensitive maize bran-poly(acrylic acid) superabsorbent hydrogel.

    Science.gov (United States)

    Zhang, Mingyue; Cheng, Zhiqiang; Zhao, Tianqi; Liu, Mengzhu; Hu, Meijuan; Li, Junfeng

    2014-09-03

    A novel composite hydrogel was prepared via UV irradiation copolymerization of acrylic acid and maize bran (MB) in the presence of composite initiator (2,2-dimethoxy-2-phenylacetophenone and ammonium persulfate) and cross-linker (N,N'-methylenebis(acrylamide)). Under the optimized conditions, maize bran-poly(acrylic acid) was obtained (2507 g g(-1) in distilled water and 658 g g(-1) in 0.9 wt % NaCl solution). Effects of granularity, salt concentration, and various cations and anions on water absorbency were investigated. It was found that swelling was extremely sensitive to the ionic strength and cation and anion type. Swelling kinetics and water diffusion mechanism in distilled water were also discussed. Moreover, the product showed excellent water retention capability under the condition of high temperature or high pressure. The salt sensitivity, good water absorbency, and excellent water retention capability of the hydrogels give this intelligentized polymer wide potential applications.

  5. Removal of dorzolamide from biomedical wastewaters with adsorption onto graphite oxide/poly(acrylic acid) grafted chitosan nanocomposite.

    Science.gov (United States)

    Kyzas, George Z; Bikiaris, Dimitrios N; Seredych, Mykola; Bandosz, Teresa J; Deliyanni, Eleni A

    2014-01-01

    A novel graphite oxide/poly(acrylic acid) grafted chitosan nanocomposite (GO/CSA) was prepared and used as biosorbent for the removal of pharmaceutical compound (dorzolamide) from biomedical synthetic wastewaters. The performance was evaluated taking into account pH, kinetics and thermodynamics of adsorption. GO/CSA presented higher adsorption capacity in comparison with the parent materials (graphite oxide and poly(acrylic acid) grafted chitosan). All adsorbents prepared were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and potentiometric titration. The surface features were also evaluated after the dorzolamide adsorption in order to derive the adsorption mechanism. It was suggested that the reactive groups of GO and CSA can interact with the amino groups of dorzolamide and mainly the abundance of carboxyl groups of GO/CSA composite was the main reason for its enhanced adsorption capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Effect of ethylene glycol dimethacrylate on swelling and on metformin hydrochloride release behavior of chemically crosslinked pH-sensitive acrylic acid-polyvinyl alcohol hydrogel

    National Research Council Canada - National Science Library

    Akhtar, Muhammad Faheem; Ranjha, Nazar Muhammad; Hanif, Muhammad

    2015-01-01

    The present work objective was to prepare and to observe the effect of ethylene glycol dimethacrylate on swelling and on drug release behavior of pH-sensitive acrylic acid-polyvinyl alcohol hydrogel...

  7. The influence of poly(acrylic) acid number average molecular weight and concentration in solution on the compressive fracture strength and modulus of a glass-ionomer restorative.

    LENUS (Irish Health Repository)

    Dowling, Adam H

    2011-06-01

    The aim was to investigate the influence of number average molecular weight and concentration of the poly(acrylic) acid (PAA) liquid constituent of a GI restorative on the compressive fracture strength (σ) and modulus (E).

  8. Structural Parameters and Swelling Behavior of pH Sensitive Poly(acrylamide-co-acrylic acid) Hydrogels

    OpenAIRE

    Thakur, A.; Wanchoo, R. K.; Singh, P

    2011-01-01

    In the present work, hydrogels based on acrylamide (AAm) and acrylic acid (AAc), crosslinked with N,N’-methylenebisacrylamide (MBAAm) were prepared by free radical polymerization in solution. The effect of initial AAm/AAc mole ratio and nominal crosslinking ratio (moles of crosslinking agent/moles of polymer repeat unit) on the dynamic and equilibrium swelling behaviour of hydrogels was investigated. Hydrogels were characterized by the polymer volume fraction in the swollen state (ν2,s ), the...

  9. A stencil printed, high energy density silver oxide battery using a novel photopolymerizable poly(acrylic acid) separator.

    Science.gov (United States)

    Braam, Kyle; Subramanian, Vivek

    2015-01-27

    A novel photopolymerized poly(acrylic acid) separator is demonstrated in a printed, high-energy-density silver oxide battery. The printed battery demonstrates a high capacity of 5.4 mA h cm(-2) at a discharge current density of 2.75 mA cm(-2) (C/2 rate) while delivering good mechanical flexibility and robustness. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Biodegradable Plastics From a Mixture of Low Density Polyethylene (Ldpe) and Cassava Starch with the Addition of Acrylic Acid

    OpenAIRE

    Susilawati, Susilawati; Mustafa, Irfan; Maulina, Desy

    2011-01-01

    A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% ) was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w) while tensile strength equal to 0,38 Kgf/mm2. SEM characterization showed that biodegradation has occurred by f...

  11. Nanopatterned polystyrene-b-poly(acrylic acid) surfaces to modulate cell-material interaction.

    Science.gov (United States)

    Lizundia, Erlantz; Sáenz-Pérez, Míriam; Patrocinio, David; Aurrekoetxea, Iskander; dM Vivanco, Maria; Vilas, José Luis

    2017-06-01

    In this work we explore the effect of surface nanoarchitecture of polystyrene (PS) and polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymer films on cell viability. PS and PS-b-PAA have been nanopatterned at temperatures of 110, 120 and 140°C using nanoporous aluminium oxide membranes (AAO) as a template. Surface architecture strongly depends on the infiltration temperature and the nature of the infiltrated polymer. High patterning temperatures yield hollow fibre shape architecture at the nanoscale level, which substantially modifies the surface hydrophobicity of the resulting materials. Up to date very scarce reports could be found in the literature dealing with the interaction of microstructured/nanostructured polymeric surfaces with cancer cells. Therefore, MCF-7 breast cancer cells have been selected as a model to conduct cell viability assays. The findings reveal that the fine-tuning of the surface nanoarchitecture contributes to the modification of its biocompatibility. Overall, this study highlights the potential of AAO membranes to obtain well-defined tailored morphologies at nanoscale level and its importance to develop novel soft functional surfaces to be used in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Investigation of small molecular weight poly(acrylic acid) adsorption on γ-alumina

    Science.gov (United States)

    Liu, Lei; Luo, Shi-Zhong; Wang, Bin; Guo, ZhanHu

    2015-08-01

    The interactions between poly(acrylic acid) (PAA) and alumina have been widely investigated. In this study, the pattern of small molecular weight PAA (MW 3000) interaction with γ-alumina has been dissected. The alumina/PAA hybrids were prepared at pH 4.0, 5.5, and 7.0, respectively. Nitrogen absorption-desorption analysis, Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analysis were conducted to illustrate the characteristics of the hybrids. At pH 4.0, the coiled PAA conformation yielded polymer adsorption primarily on alumina outer surface. At higher pH values, the more stretched PAA molecules were able to infiltrate inside the alumina pores. The phenomenon is explained by the polymer chain reptation motion model. Coiled polymer chains are not oriented enough to penetrate the oxide pore channels. In contrary, stretched polymer chains are more likely to move along the pore channels.

  13. Synthesis of hemicellulose-acrylic acid graft copolymer super water absorbent resin by ultrasonic irradiation technology

    Directory of Open Access Journals (Sweden)

    Fangfang LIU

    2015-12-01

    Full Text Available The hemicellulose super water absorbent resin is prepared by using ultrasonic irradiation technology, with the waste liquid produced during the preparation of viscose fiber which contains a large amount of hemicellulose as raw material, acrylic acid as graft monomer, N,N’-methylene bis acrylamide (NMBA as cross linking agent, and (NH42S2O8-NaHSO3 as the redox initiation system. The synthesis conditions, structure and water absorption ability of resin are discussed. The results indicate that water absorbency of the resin is 311 g/g, the tap water absorbency is 102 g/g, the normal saline absorbency is 55 g/g, and the artificial urine absorbency is 31 g/g under the optimal synthesis conditions, so the resin has great water absorption rate and water retaining capacity. The FT-IR and SEM analysis shows that the resin with honeycomb network structure is prepared. The successfully synthesized of the resin means that the hemicellulose waste liquid can be highly effectively recycled, and it provides a kind of new raw material for the synthesis of super water absorbent resin.

  14. Mechanical, thermal and morphological properties of poly(lactic acid)/ethylene-butyl acrylate copolymer nanocomposites

    Science.gov (United States)

    Wacharawichanant, S.; Hoysang, P.; Ratchawong, S.

    2017-07-01

    This paper reports a melt blend of poly(lactic acid) (PLA)/ethylene-butyl acrylate copolymer (EBAC) with organoclay content at 3 phr. The mechanical, thermal and morphological properties of PLA/EBAC blends and nanocomposites were investigated. The morphological analysis revealed EBAC phase dispersed as a spherical domain in PLA matrix and the domain size of EBAC dispersed phase increased with increasing EBAC content. The addition of organoclay could improve the miscibility of PLA/EBAC blends due to the decrease of domain size of EBAC dispersed phase. The mechanical properties indicated that the strain at break and impact strength of PLA increased when added EBAC, but Young’s modulus and tensile strength decreased. Storage modulus increased with the addition of organoclay to the PLA/EBAC blends. The thermal properties found that the incorporation of organoclay in the PLA/EBAC blends did not effect on the glass transition temperature and melting temperature values relative to PLA. The degradation temperature of PLA improved with the addition of EBAC. This indicated that EBAC has more thermal stability and degradation temperature than PLA. From X-ray diffraction patterns displayed the characteristic peak in PLA/EBAC/organoclay nanocomposites appeared at the lower angle, which indicated the dispersed clay is intercalated in the polymer matrix. However, second-order diffraction peak appeared at the higher angle indicated that there was partially the conventional composite.

  15. Preparation and properties of poly(acrylic acid) oligomer stabilized superparamagnetic ferrofluid.

    Science.gov (United States)

    Lin, Chia-Lung; Lee, Chia-Fen; Chiu, Wen-Yen

    2005-11-15

    Ferrofluids, which are stable dispersions of magnetic particles, behave as liquids that have strong magnetic properties. Nanoparticles of magnetite with a mean diameter of 10-15 nm, which are in the range of superparamagnetism, are usually prepared by the traditional method of co-precipitation from ferrous and ferric electrolyte solution. When diluted, the ferrofluid dispersions are not stable if anionic or cationic surfactants are used as the stabilizer. This work presents an efficient way to prepare a stable aqueous nanomagnetite dispersion. A stable ferrofluid containing Fe3O4 nanoparticles was synthesized via co-precipitation in the presence of poly(acrylic acid) oligomer. The mechanism, microstructure, and properties of the ferrofluid were investigated. The results indicate that the PAA oligomers promoted the nucleation and inhibited the growth of the magnetic iron oxide, and the average diameter of each individual Fe3O4 particle was smaller than 10 nm. In addition, the PAA oligomers provided both electrostatic and steric repulsion against particle aggregation, and the stability of dispersions could be controlled by adjusting the pH value of solution. A small amount of Fe2O3 was found in the nanoparticles but the superparamagnetic behavior of the nanoparticles was not affected.

  16. Sustained release gastroretentive tablet of metformin hydrochloride based on poly (acrylic acid)-grafted-gellan.

    Science.gov (United States)

    Sarkar, Debjani; Nandi, Gouranga; Changder, Abhijit; Hudati, Prasenjit; Sarkar, Sayani; Ghosh, Lakshmi Kanta

    2017-03-01

    Development of a gastroretentive sustained release tablet of metformin based on poly (acrylic acid)-grafted-gellan (PAAc-g-GG) is the main purpose of this study. At first, PAAc-g-GG was synthesized by microwave-promoted free radical initiation method using cerric (IV) ammonium nitrate (CAN) as redox initiator and characterized by elemental analysis, FTIR, DSC-TGA, (13)C NMR, biodegradation and viscosity study. The synthetic parameters were optimized by 2(3) full factorial design using Design Expert software. Acute oral toxicity and histological studies were also performed as per OECD guideline. Tablets were then prepared employing wet granulation method using PAAc-g-GG and evaluated for various physical characters, in vitro drug release, ex-vivo mucoadhesion and swelling. Compatibility between drug and excipients was checked by DSC and FTIR analysis. The F3 batch showed excellent mucoadhesion and sustained drug release over a period of 10h with dissolution similarity factor, f2=77.43. Kinetic modeling unveiled Case-1 Fickian diffusion based drug release mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Properties of copper micropowders electroplated from sulfate solutions with acrylic acid or acrylamide

    Directory of Open Access Journals (Sweden)

    Viktor F. Vargalyuk

    2014-03-01

    Full Text Available Based on the results of X-ray diffraction analysis it has been ascertained that cathodic copper deposit precipitated from sulfate electrolyte with acrylic acid or acrylamide consist of copper crystals with considerable quantity of imperfections and crystal deformations. It has been revealed that microstress and dislocation density in the deposits increase with enhancement of organic component concentration in the solution according to symbasis dependences. Decreasing of crystallite size and increasing of structuring degree for the deposits has been observed. Peaks of any phases except copper have not been identified on X-ray diffraction pattern of the deposits. In earlier investigation it has been shown that nonmetallic component (copper π-complexes makes up 20% of the deposits. So based on the results of X-ray diffraction investigations we can conclude that the deposit consist of copper micro crystals separated by nonmetallic component. Owing to special physical-mechanical properties of the deposits it became possible to transform them to superfine powder by means of mechanical fragmentation. Using sedimentation and microscopic analysis it has been shown that cathodic micro powders precipitated from solutions with organic compounds are homogeneous by form and dimension. Significant bactericidal and bacteriostatic effects of cathodic micro powders influence have been detected.

  18. Improved biotribological properties of PEEK by photo-induced graft polymerization of acrylic acid.

    Science.gov (United States)

    Zhao, Xiaoduo; Xiong, Dangsheng; Wang, Kun; Wang, Nan

    2017-06-01

    The keys of biomaterials application in artificial joints are good hydrophilicity and wear resistance. One kind of the potential bio-implant materials is polyetheretherketone (PEEK), which has some excellent properties such as non-toxic and good biocompatibility. However, its bioinert surface and inherent chemical inertness hinder its application. In this study, we reported an efficient method for improving the surface wettability and wear resistance for PEEK, a layer of acrylic acid (AA) polymer brushes on PEEK surface was prepared by UV-initiated graft polymerization. The effects of different grafting parameters (UV-irradiation time/AA monomer solution concentration) on surface characteristics were clearly investigated, and the AA-g-PEEK specimens were examined by ATR-FTIR, static water contact angle measurements and friction tests. Our results reveal that AA can be successfully grafted onto the PEEK surface after UV irradiation, the water wettability and tribological properties of AA-g-PEEK are much better than untreated PEEK because that AA is a hydrophilic monomer, the AA layer on PEEK surface can improve its bearing capacity and reduce abrasion. This detailed understanding of the grafting parameters allows us to accurately control the experimental products, and this method of surface modification broadens the use of PEEK in orthopedic implants. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Polyelectrolyte Complex Nanoparticles of Poly(ethyleneimine and Poly(acrylic acid: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Martin Müller

    2011-04-01

    Full Text Available In this contribution we outline polyelectrolyte (PEL complex (PEC nanoparticles, prepared by mixing solutions of the low cost PEL components poly(ethyleneimine (PEI and poly(acrylic acid (PAC. It was found, that the size and internal structure of PEI/PAC particles can be regulated by process, media and structural parameters. Especially, mixing order, mixing ratio, PEL concentration, pH and molecular weight, were found to be sensible parameters to regulate the size (diameter of spherical PEI/PAC nanoparticles, in the range between 80–1,000 nm, in a defined way. Finally, applications of dispersed PEI/PAC particles as additives for the paper making process, as well as for drug delivery, are outlined. PEI/PAC nanoparticles mixed directly on model cellulose film showed a higher adsorption level applying the mixing order 1. PAC 2. PEI compared to 1. PEI 2. PAC. Surface bound PEI/PAC nanoparticles were found to release a model drug compound and to stay immobilized due to the contact with the aqueous release medium.

  20. Osmotic Engine: Translating Osmotic Pressure into Macroscopic Mechanical Force via Poly(Acrylic Acid) Based Hydrogels

    Science.gov (United States)

    Arens, Lukas; Weißenfeld, Felix; Klein, Christopher O.; Schlag, Karin

    2017-01-01

    Poly(acrylic acid)‐based hydrogels can swell up to 100–1000 times their own weight in desalinated water due to osmotic forces. As the swelling is about a factor of 2–12 lower in seawater‐like saline solutions (4.3 wt% NaCl) than in deionized water, cyclic swelling, and shrinking can potentially be used to move a piston in an osmotic motor. Consequently, chemical energy is translated into mechanical energy. This conversion is driven by differences in chemical potential and by changes in entropy. This is special, as most thermodynamic engines rely instead on the conversion of heat into mechanical energy. To optimize the efficiency of this process, the degree of neutralization, the degree of crosslinking, and the particle size of the hydrogels are varied. Additionally, different osmotic engine prototypes are constructed. The maximum mean power of 0.23 W kg−1 dry hydrogel is found by using an external load of 6 kPa, a polymer with 1.7 mol% crosslinking, a degree of neutralization of 10 mol%, and a particle size of 370–670 µm. As this is achieved only in the first round of optimization, higher values of the maximum power average over one cycle seem realistic. PMID:28932675

  1. Multiplex Immunoassay Platforms Based on Shape-Coded Poly(ethylene glycol) Hydrogel Microparticles Incorporating Acrylic Acid

    Science.gov (United States)

    Park, Saemi; Lee, Hyun Jong; Koh, Won-Gun

    2012-01-01

    A suspension protein microarray was developed using shape-coded poly(ethylene glycol) (PEG) hydrogel microparticles for potential applications in multiplex and high-throughput immunoassays. A simple photopatterning process produced various shapes of hydrogel micropatterns that were weakly bound to poly(dimethylsiloxane) (PDMS)-coated substrates. These micropatterns were easily detached from substrates during the washing process and were collected as non-spherical microparticles. Acrylic acids were incorporated into hydrogels, which could covalently immobilize proteins onto their surfaces due to the presence of carboxyl groups. The amount of immobilized protein increased with the amount of acrylic acid due to more available carboxyl groups. Saturation was reached at 25% v/v of acrylic acid. Immunoassays with IgG and IgM immobilized onto hydrogel microparticles were successfully performed with a linear concentration range from 0 to 500 ng/mL of anti-IgG and anti-IgM, respectively. Finally, a mixture of two different shapes of hydrogel microparticles immobilizing IgG (circle) and IgM (square) was prepared and it was demonstrated that simultaneous detection of two different target proteins was possible without cross-talk using same fluorescence indicator because each immunoassay was easily identified by the shapes of hydrogel microparticles. PMID:22969408

  2. Preparation and electro-response of chitosan-g-poly (acrylic acid) hydrogel elastomers with interpenetrating network

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianli [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Gao, Ling-xiang, E-mail: gaolx@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China); Han, Xuewu; Chen, Tao; Luo, Jue; Liu, Kaiqiang; Gao, Ziwei; Zhang, Weiqiang [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi' an, 710062 (China); School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi' an, 710062 (China)

    2016-02-01

    In this article, novel chitosan-g-poly (acrylic acid) hydrogel elastomers were successfully sythesised by grafting chitosan (CTS) onto poly acrylic acid (PAA) through radical polymerization in the presence/absence of direct current electric field. Their structure and electro-response were evaluated through scanning electron microscopy (SEM), infrared spectroscopy (IR), and dynamic mechanical analyser (DMA), respectively. Stress-strain test showed that the toughness of the chitosan-g-PAA elastomer is higher than the PAA gel. The result demonstrates the elastomers obtained in the presence/absence of electric field with similar chemical composition possess different microstructure. The positive electro responsive effect appeared on the elastomers, and both of storage modulus increment and increment sensitivity yielded maximum value at the AA concentration of 14.09 wt% under the applied electric field of 1.5 kV/mm. Thermo gravimetry and differential scanning calorimetry (TG-DSC) showed the elastomers cured under an applied electric field have stronger intramolecular bonding and higher cross-linking density. - Highlights: • The chitosan-g-poly (acrylic acid) hydrogel elastomers have been prepared. • They have ordered structure and positive electro-response under an electric field. • The maximum electro-response occurs near or at the AA wt% of 14.09 under 1.5 kV/mm.

  3. Sodium Carboxymethyl Cellulose Using Acrylamide and Acrylic Acid and Investigation of Drug Delivery Properties

    Directory of Open Access Journals (Sweden)

    Mahdi Geramipour

    2016-07-01

    Full Text Available Hydrogels are three-dimensional polymer networks that can absorb and retain a huge amount of aqueous fluids even under certain pressure, but do not dissolve in water. They are responsive to environmental stimulants such as pH and ionic strength of the solution. In this study, a series of novel sodium carboxymethyl cellulose-based hydrogel nanocomposites were synthesized using acrylamide comonomer in the presence of iron magnetic as crosslinker and acrylic acid ammonium persulfate (APS comonomer as initiator. All reaction variables affecting the water absorbency of the hydrogel nanocomposite including the concentration of crosslinking agent and initiator, and comonomers ratio were optimized in order to achieve the maximum absorption capacity. The experimental data showed that the hydrogel nanocomposite exhibited improved swelling capacity compared to the nanoparticel-free hydrogel. In addition, optimized hydrogel nanocomposite showed a good water uptake ability and the equilibrium swelling capacity was achieved within the initial 10 min. In examining the quality of the synthesized hydrogel nanocomposite, the amount of absorption in saline solutions of different concentrations was measured. Furthermore, the swelling behavior of hydrogel nanocomposite in solutions with different pH values was evaluated. The chemical structure of the hydrogel nanocomposites was characterized by means of transmission electron microscopy (TEM, scanning electron microscopy (SEM, vibrating sample magnetometry (VSM, thermogravimetry analysis (TGA, derivative thermogravimetry (DTG and Fourier transform infrared spectroscopy (FTIR. In order to study the drug delivery and drug release behavior, the release of sodium diclofenac as a model drug from synthesized hydrogel nanocomposite was examined in two acidic and basic buffer environments. The results indicated that this hydrogel nanocomposite may be an appropriate alternative for drug release processes in human body.

  4. Synthesis and swelling property of superabsorbent starch grafted with acrylic acid/2-acrylamido-2-methyl-1-propanesulfonic acid.

    Science.gov (United States)

    Meng, Yeqiao; Ye, Lin

    2017-08-01

    In order to develop starch-based superabsorbent polymers (SAPs) with high water absorbency, both acrylic acid (AA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) were graft copolymerized onto cassava starch, and St-g-AA-AMPS SAP was successfully synthesized. The effect of AA/AMPS molar ratio on the structure and swelling property of SAP was investigated. Introduction of AMPS units improved the storage modulus and crosslinking density of St-g-AA-AMPS SAP, and was beneficial in forming a perfect network structure. With increasing AMPS content, the equilibrium swelling ratio and swelling rate constant (k) of the SAP first increased and then decreased, and the maximum swelling ratio reached 1200.0 and 90.0 g/g in distilled water and brine respectively, resulting from the high ionization constant and hydrophilic ability of AMPS, and improved tolerance to brine. By introducing AMPS units, the re-swelling capability of SAP was improved, and more hydrogen bonds could form between molecules of water and SAP, leading to an increase in non-freezing bound water and freezing bound water, and the water retention of SAP was enhanced. Introduction of AMPS units improved the water absorption capacity, swelling rate, and water retention ability of St-g-AA-AMPS SAP, presenting wide application potential in agriculture and horticulture of desert regions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Optimal Design for Reactivity Ratio Estimation: A Comparison of Techniques for AMPS/Acrylamide and AMPS/Acrylic Acid Copolymerizations

    OpenAIRE

    Scott, Alison J.; Marzieh Riahinezhad; Alexander Penlidis

    2015-01-01

    Water-soluble polymers of acrylamide (AAm) and acrylic acid (AAc) have significant potential in enhanced oil recovery, as well as in other specialty applications. To improve the shear strength of the polymer, a third comonomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), can be added to the pre-polymerization mixture. Copolymerization kinetics of AAm/AAc are well studied, but little is known about the other comonomer pairs (AMPS/AAm and AMPS/AAc). Hence, reactivity ratios for AMPS/AAm ...

  6. Mechanisms and Origins of Selectivities of the Lewis Acid-Catalyzed Diels-Alder Reactions between Arylallenes and Acrylates.

    Science.gov (United States)

    Yu, Peiyuan; Li, Wei; Houk, K N

    2017-06-16

    The mechanisms of recently reported Lewis acid-catalyzed Diels-Alder reactions of arylallenes and acrylates were studied using density functional theory calculations. A stepwise mechanism involving short-lived zwitterion intermediates is established. The reaction is endo-selective in the presence of Lewis acid catalyst. The [2 + 2] cycloaddition is not observed because of the greater charge separation in the first step of the [2 + 2] cycloaddition. The origins of chirality transfer in the Diels-Alder reaction using chiral arylallenes are uncovered, and the absolute stereochemistry of the product is predicted.

  7. Fracture Mechanisms of Layer-By-Layer Polyurethane/Poly(Acrylic Acid) Nanocomposite

    Science.gov (United States)

    Kheng, Eugene R.

    A layer-by-layer(LBL) manufactured material is examined in detail in this thesis. Improvements are made to the method of its manufacture. Efforts are made to understand its fracture mechanisms and take advantage of these fracture mechanisms in the absorption of impact energy. A novel series of experiments has been performed on LBL manufactured thin films to demonstrate their unique fracture mechanisms. Polyurethane/Poly(Acrylic Acid) (PU/PAA) and PU/PAA/(PU/Clay)5 nanocomposite films readily undergo Interlaminar mode II fracture, because of the relatively weak elctrostatic bonds between monolayers. Tensile tests performed while under observation by a scanning electron microscope demonstrate the tendency of these nanocomposite films to undergo interlaminar mode II fracture even when loads are applied in the plane of nanocomposite film. It is concluded that these mechanisms of energy dissipation are responsible for the enhanced toughness of these films when used as layers between glass blocks in the prevention of impact damage to the glass. A novel automated manufacturing facility has been designed and built to deposit large sheets of Layer-by-Layer nanocomposite film. These large sheets are incorporated into a borosillicate glass composite in order to compare the ballistic characteristics of LBL PU based nanocomposite films to a single cast layer of polyurethane. It is demonstrated that shear fracture is the mode of failure in the blocks containing the nanocomposite film. The shear fracture surface in the nanocomposite after it has undergone a ballistic impact is characterized. Additional experiments are performed to characterize the interlaminar fracture stresses and toughnesses of the nanocomposite LBL layers, to assist in the implementation of a numerical crack band model that describes the nanocomposite film. The computational model predicts the failure of the ballistic nanocomposite samples, and the predicted V50 velocity is found to be in good agreement with

  8. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Science.gov (United States)

    Hui, Alex; Sheardown, Heather; Jones, Lyndon

    2012-01-01

    Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted) tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted) tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials. PMID:28817033

  9. Biocompatibility and bond degradation of poly-acrylic acid coated copper iodide-adhesives.

    Science.gov (United States)

    ALGhanem, Adi; Fernandes, Gabriela; Visser, Michelle; Dziak, Rosemary; Renné, Walter G; Sabatini, Camila

    2017-09-01

    To investigate the effect of poly-acrylic acid (PAA) copper iodide (CuI) adhesives on bond degradation, tensile strength, and biocompatibility. PAA-CuI particles were incorporated into Optibond XTR, Optibond Solo and XP Bond in 0.1 and 0.5mg/ml. Clearfil SE Protect, an MDPB-containing adhesive, was used as control. The adhesives were applied to human dentin, polymerized and restored with composite in 2mm-increments. Resin-dentin beams (0.9±0.1mm2) were evaluated for micro-tensile bond strength after 24h, 6 months and 1year. Hourglass specimens (10×2×1mm) were evaluated for ultimate tensile strength (UTS). Cell metabolic function of human gingival fibroblast cells exposed to adhesive discs (8×1mm) was assessed with MTT assay. Copper release from adhesive discs (5×1mm) was evaluated with UV-vis spectrophotometer after immersion in 0.9% NaCl for 1, 3, 5, 7, 10, 14, 21 and 30 days. SEM, EDX and XRF were conducted for microstructure characterization. XTR and Solo did not show degradation when modified with PAA-CuI regardless of the concentration. The UTS for adhesives containing PAA-CuI remained unaltered relative to the controls. The percent viable cells were reduced for Solo 0.5mg/ml and XP 0.1 or 0.5mg/ml PAA-CuI. XP demonstrated the highest ion release. For all groups, the highest release was observed at days 1 and 14. PAA-CuI particles prevented the bond degradation of XTR and Solo after 1year without an effect on the UTS for any adhesive. Cell viability was affected for some adhesives. A similar pattern of copper release was demonstrated for all adhesives. Copyright © 2017. Published by Elsevier Ltd.

  10. Acetic and Acrylic Acid Molecular Imprinted Model Silicone Hydrogel Materials for Ciprofloxacin-HCl Delivery

    Directory of Open Access Journals (Sweden)

    Lyndon Jones

    2012-01-01

    Full Text Available Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

  11. The Effect of Double Crosslinker on Precipitation Polymerization of Poly(acrylic acid

    Directory of Open Access Journals (Sweden)

    Hajar Es-haghi

    2014-06-01

    Full Text Available Cross-linked poly(acrylic acids were prepared by dual cross-linkers via precipitation polymerization method in a binary organic solvent. Polyethylene glycol diacrylate (PEGDA-400 as a long-chain cross-linker and di(trimethylol propane tetraacrylate (DTMPTA as multifunctional cross-linker were used. PEGDA-400 was utilized to increase thickening properties and DTMPTA was used to improve the gel strength. The dual cross-linkers effect on the sample features (i.e., equilibrium swelling, thickening properties and rheological properties was investigated. Maximum amount of swelling was obtained by a high percentage of long-chain cross-linker. The apparent viscosity of the microgels was measured to determine their thickening properties for aqueous media. Maximum viscosity occurred at DT25-PE75 which was dependent on the type of cross-linkers in the polymer structure. The Flory-Rehner equation (from swelling ratio data and rubber elasticity theory (from rheometry data were used to discuss the network structure of the polymer. Increasing density of the network was shown by a sample containing high percentage of a four-functional cross-linker. The rheological properties of the cross-linked polymers were measured to determine storage modulus (strength network. The rheological behaviors demonstrated that the synthesized polymer containing a high amount of four-functional cross-linker had higher storage modulus (G′ than other samples. In addition the consistency coefficient (m and flow behavior index (n parameters of Ostwald equation were investigated as well. As a result, n values in each sample were found to be smaller than 1 and these results were fitted clearly with the pseudoplastic model. Apparent and rotational viscosities were used to determine the optimal cross-linker type (synthesized sample contained a high percentage of long-chain cross-linker.

  12. Oral peptide delivery: in-vitro evaluation of thiolated alginate/poly(acrylic acid) microparticles.

    Science.gov (United States)

    Greimel, Alexander; Werle, Martin; Bernkop-Schnürch, Andreas

    2007-09-01

    The purpose of this study was to develop an oral thiomer-based microparticulate delivery system for insulin by ionic gelation. The microparticulate matrix consisted of either poly(acrylic acid)-cysteine (PAA-Cys) and alginate-cysteine (Alg-Cys) or the corresponding unmodified polymers (PAA, Alg). Two different viscosities of alginates were provided for the study, low and medium. Three different types of microparticles were prepared via ionic gelation with calcium (Alg, AlgPAA and AlgPAA-Cys) and their different properties evaluated in-vitro (particle size and shape, drug loading and release profile, swelling and stability). The mean particle size of all formulations ranged from 400 to 600 microm, revealing the lowest for thiolated microparticles. SEM micrographs showed different morphological profiles for the three different types of microparticles. Encapsulation efficiency of insulin increased within the following rank order: Alg (15%) Alginate and AlgPAA microparticles displayed a burst release after 30 min, whereas the thiolated particles achieved a controlled release of insulin over 3 h. The swelling ratio was pH dependent: in simulated intestinal fluid microparticles exhibited a much higher water uptake compared with simulated gastric fluid. Due to the formation of intraparticulate disulfide bonds during the preparation process, thiolated particles revealed a higher stability. It was also observed that the viscosity of the two alginates used had no influence on the properties of the particles. According to these results AlgPAA-Cys microparticles obtained by ionic gelation and stabilized via disulfide bonds might be an alternative tool for the oral administration of therapeutic peptides.

  13. Acrylates in contact dermatitis.

    Science.gov (United States)

    Sasseville, Denis

    2012-01-01

    Acrylates are plastic materials that are formed by the polymerization of monomers derived from acrylic or methacrylic acid. They have found numerous applications in paints, varnishes and adhesives, in the printing industry, in the medical and dental professions, and in artificial nails. Beginning in the 1950s, many reports of occupational and nonoccupational allergic contact dermatitis to (meth)acrylate monomers have been published. These molecules are strong irritants, and patch testing can induce active sensitization. When patch tested, acrylate-allergic patients often display multiple positive tests. These reactions may represent cross-reactions, or concomitant reactions due to the presence, in the products responsible for sensitization, of impurities not disclosed in material safety data sheets. (Meth)acrylates are volatile and unstable chemicals, as demonstrated by their rapid disappearance from commercially available patch test allergens when exposed to air for more than a few hours.

  14. Tuning of thermally induced sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid).

    Science.gov (United States)

    Jin, Naixiong; Zhang, Hao; Jin, Shi; Dadmun, Mark D; Zhao, Bin

    2012-03-15

    We report in this article a method to tune the sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers that consist of two blocks exhibiting distinct lower critical solution temperatures (LCSTs) in water. A small amount of weak acid groups is statistically incorporated into the lower LCST block so that its LCST can be tuned by varying solution pH. Well-defined diblock copolymers, poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid) (PTEGMA-b-P(DEGEA-co-AA)), were prepared by reversible addition-fragmentation chain transfer polymerization and postpolymerization modification. PTEGMA and PDEGEA are thermosensitive water-soluble polymers with LCSTs of 58 and 9 °C, respectively, in water. A 25 wt % aqueous solution of PTEGMA-b-P(DEGEA-co-AA) with a molar ratio of DEGEA to AA units of 100:5.2 at pH = 3.24 underwent multiple phase transitions upon heating, from a clear, free-flowing liquid (<15 °C) to a clear, free-standing gel (15-46 °C) to a clear, free-flowing hot liquid (47-56 °C), and a cloudy mixture (≥57 °C). With the increase of pH, the sol-to-gel transition temperature (T(sol-gel)) shifted to higher values, while the gel-to-sol transition (T(gel-sol)) and the clouding temperature (T(clouding)) of the sample remained essentially the same. These transitions and the tunability of T(sol-gel) originated from the thermosensitive properties of two blocks of the diblock copolymer and the pH dependence of the LCST of P(DEGEA-co-AA), which were confirmed by dynamic light scattering and differential scanning calorimetry studies. Using the vial inversion test method, we mapped out the C-shaped sol-gel phase diagrams of the diblock copolymer in aqueous buffers in the moderate concentration range at three different pH values (3.24, 5.58, and 5.82, all measured at ~0 °C). While the upper temperature boundaries overlapped, the lower temperature boundary

  15. Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.

    Science.gov (United States)

    Ruiz, Sara Melisa Arciniegas; Olvera, Lilia Gutiérrez; Chacón, Sara del Carmen Caballero; Estrada, Dinorah Vargas

    2015-04-01

    To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices. 30 healthy adult dogs. In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment. Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment. Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 μg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.

  16. Comparison of the swelling kinetics of a partially neutralized poly(acrylic acid) hydrogel in distilled water and physiological solution

    OpenAIRE

    ALEKSANDAR KOSTIC; BORIVOJ ADNADJEVIC; ALEKSANDAR POPOVIC; JELENA JOVANOVIC

    2007-01-01

    The isothermal kinetics curves of the swelling of a poly(acrylic acid) hydrogel in distilled water and physiological solution at temperatures ranging from 20 to 40 ºC were determined. The possibility of applying both the Fick’s kinetics model and kinetics model of the first order chemical reaction to the swelling kinetics of the PAA hydrogel in distilled water and physiological solution were examined. It was found that the possibilities of applying these models were limited. The new model of ...

  17. Biocompatibility of poly(ethylene glycol) and poly(acrylic acid) interpenetrating network hydrogel by intrastromal implantation in rabbit cornea

    OpenAIRE

    Zheng, Luo Luo; Vanchinathan, Vijay; Dalal, Roopa; Noolandi, Jaan; Waters, Dale J.; Hartmann, Laura; Cochran, Jennifer R.; Frank, Curtis W.; Yu, Charles Q.; Ta, Christopher N.

    2015-01-01

    We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 m...

  18. Preparation of Superabsorbent Resin from Carboxymethyl Cellulose Grafted with Acrylic Acid by Low-temperature Plasma Treatment

    OpenAIRE

    Li Jie Huang; Ying Yang; Yuan Yuan Cai; Ming Liu; Ting Xu; Guang Zai Nong; Shuang Fei Wang

    2014-01-01

    A superabsorbent resin (SAR) synthesized from carboxymethyl cellulose (CMC) by grafting acrylic acid (AA) was studied using single-factor analysis. The optimum preparation conditions were as follows: plasma discharge power of 250 W, processing time of 90 s, pressure of 300 Pa, m(CMC):m(AA) ratio of 1:9, m(K2S2O8):m(CMC) ratio of 1:4, and neutralization degree of 40%. Under these conditions, the resin has a salt water absorbency of 38.5 g/g and a stable chlorine dioxide solution absorbency of ...

  19. Molecularly imprinted films of acrylonitrile/methyl methacrylate/acrylic acid terpolymers: influence of methyl methacrylate in the binding performance of L-ephedrine imprinted films.

    Science.gov (United States)

    Brisbane, Carrie; McCluskey, Adam; Bowyer, Michael; Holdsworth, Clovia I

    2013-05-07

    Molecularly imprinted polymeric films (MIPFs) highly selective to 1R,2S(-)ephedrine (L-ephedrine, EPD) were produced by phase inversion post-polymerization imprinting on poly(acrylonitrile-co-methyl methacrylate-co-acrylic acid) (PAMA) terpolymers. The inclusion of methyl methacrylate (MMA) to the polymer formulation resulted in enhanced EPD selectivity which appears to be dictated by polymer composition to achieve the necessary balance between polymer rigidity and porosity. Substitution of MMA with methyl acrylate, ethyl acrylate and n-butyl acrylate resulted in a loss of EPD selectivity and EPD entrapment within the polymer matrix not observed in PAMA MIPFs. MMA, by virtue of its methyl group, is able to provide the scaffolding and rigidity necessary for stability and preservation of imprinted cavities within the PAMA MIPF leading to high EPD selectivity.

  20. Chemically Cross-Linked Poly(acrylic-co-vinylsulfonic Acid Hydrogel for the Delivery of Isosorbide Mononitrate

    Directory of Open Access Journals (Sweden)

    Talib Hussain

    2013-01-01

    Full Text Available We report synthesis, characterization, and drug release attributes of a series of novel pH-sensitive poly(acrylic-co-vinylsulfonic acid hydrogels. These hydrogels were prepared by employing free radical polymerization using ethylene glycol dimethacrylate (EGDMA and benzyl peroxide (BPO as cross-linker and initiator, respectively. Effect of acrylic acid (AA, polyvinylsulfonic acid (PVSA, and EGDMA on prepared hydrogels was investigated. All formulations showed higher swelling at high pHs and vice versa. Formulations containing higher content of AA and EGDMA show reduced swelling, but one with higher content of PVSA showed increased swelling. Hydrogel network was characterized by determining structural parameters and loaded with isosorbide mononitrate. FTIR confirmed absence of drug polymer interaction while DSC and TGA demonstrated molecular dispersion of drug in a thermally stable polymeric network. All the hydrogel formulations exhibited a pH dependent release of isosorbide mononitrate which was found to be directly proportional to pH of the medium and PVSA content and inversely proportional to the AA contents. Drug release data were fitted to various kinetics models. Results indicated that release of isosorbide mononitrate from poly(AA-co-VSA hydrogels was non-Fickian and that the mechanism was diffusion-controlled.

  1. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes.

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; Foster, Nicholas; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2017-10-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such as styrene maleic acid (SMA) for the solubilisation, purification and characterisation of integral membrane proteins in the form of protein/lipid nanodiscs. Here we survey the effectiveness of various commercially-available formulations of the SMA copolymer in solubilising Rhodobacter sphaeroides reaction centres (RCs) from photosynthetic membranes. We find that formulations of SMA with a 2:1 or 3:1 ratio of styrene to maleic acid are almost as effective as detergent in solubilising RCs, with the best solubilisation by short chain variants (membranes was uniformly low, but could be increased through a variety of treatments to increase the lipid:protein ratio. However, proteins isolated from such membranes comprised clusters of complexes in small membrane patches rather than individual proteins. We conclude that short-chain 2:1 and 3:1 formulations of SMA are the most effective in solubilising integral membrane proteins, but that solubilisation efficiencies are strongly influenced by the size of the target protein and the density of packing of proteins in the membrane. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Poly (acrylic acid sodium) grafted carboxymethyl cellulose as a high performance polymer binder for silicon anode in lithium ion batteries

    Science.gov (United States)

    Wei, Liangming; Chen, Changxin; Hou, Zhongyu; Wei, Hao

    2016-01-01

    The design of novel binder systems is required for the high capacity silicon (Si) anodes which usually undergo huge volume change during the charge/discharge cycling. Here, we introduce a poly (acrylic acid sodium)-grafted-carboxymethyl cellulose (NaPAA-g-CMC) copolymer as an excellent binder for Si anode in lithium ion batteries (LIBs). The NaPAA-g-CMC copolymer was prepared via a free radical graft polymerization method by using CMC and acrylic acid as precursors. Unlike the linear, one-dimensional binders, the NaPAA-g-CMC copolymer binder is expected to present multi-point interaction with Si surface, resulting in enhanced binding ability with Si particles as well as with the copper (Cu) current collectors, and building a stable solid electrolyte interface (SEI) layer on the Si surface. The NaPAA-g-CMC based Si anode shows much better cycle stability and higher coulombic efficiency than those made with the well-known linear polymeric binders such as CMC and NaPPA. PMID:26786315

  3. Developing the potential ophthalmic applications of pilocarpine entrapped into polyvinylpyrrolidone-poly(acrylic acid) nanogel dispersions prepared by γ radiation.

    Science.gov (United States)

    Abd El-Rehim, Hassan A; Swilem, Ahmed E; Klingner, Anke; Hegazy, El-Sayed A; Hamed, Ashraf A

    2013-03-11

    The aim of this study was to improve the stability and bioavailability of pilocarpine in order to maintain an adequate concentration of the pilocarpine at the site of action for prolonged period of time. Thus, pH-sensitive polyvinylpyrrolidone-poly(acrylic acid) (PVP/PAAc) nanogels prepared by γ radiation-induced polymerization of acrylic acid (AAc) in an aqueous solution of polyvinylpyrrolidone (PVP) as a template polymer were used to encapsulate pilocarpine. Factors affecting size and encapsulation efficiency were optimized to obtain nanogel suitable for entrapping drug efficiently. The PVP/PAAc nanogel particles were characterized by dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), and their size can be controlled by the feed composition and concentration as well as the irradiation dose. Pilocarpine was loaded into the nanogel particles through electrostatic interactions where the AAc-rich nanogels exhibited the highest loading efficiency. The transmittance, mucoadhesion, and rheological characteristics of the nanogel particles were studied to evaluate their ocular applicability. The in vitro release study conducted in simulated tear fluid showed a relatively long sustained release of pilocarpine from the prepared PVP/PAAc nanogel particles if compared with pilocarpine in solution.

  4. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  5. Physicochemical properties of poly(lactic acid-co-glycolic acid film modified via blending with poly(butyl acrylate-co-methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Guoquan Zhu

    2013-01-01

    Full Text Available A series of poly(lactic acid-co-glycolic acid (PLGA/poly(butyl acrylate-co-methyl methacrylate (P(BA-co-MMA blend films with different P(BA-co-MMA mole contents were prepared by casting the polymer blend solution in chloroform. Surface morphologies of the PLGAP(BA-co-MMA blend films were studied by scanning electron microscopy (SEM. Thermal, mechanical, and chemical properties of PLGAP(BA-co-MMA blend films were investigated by differential scanning calorimeter (DSC, thermogravimetric analysis (TGA, tensile tests, and surface contact angle tests. The introduction of P(BA-co-MMA could modify the properties of PLGA films.

  6. Ion-exclusion chromatographic behavior of aliphatic carboxylic acids and benzenecarboxylic acids on a sulfonated styrene--divinylbenzene co-polymer resin column with sulfuric acid containing various alcohols as eluent.

    Science.gov (United States)

    Ohta, Kazutoku; Towata, Atsuya; Ohashi, Masayoshi

    2003-05-16

    The addition of C1-C7 alcohols (methanol, ethanol, propanol, butanol, heptanol, hexanol and heptanol) to dilute sulfuric acid as eluent in ion-exclusion chromatography using a highly sulfonated styrene-divinylbenzene co-polymer resin (TSKgel SCX) in the H+ form as the stationary phase was carried out for the simultaneous separations of both (a) C1-C7 aliphatic carboxylic acids (formic, acetic, propionic, isobutyric, butyric, isovaleric, valeric, 2-methylvaleric, isocaproic, caproic, 2,2-dimethyl-n-valeric, 2-methylhexanoic, 5-methylhexanoic and heptanoic acids) and (b) benzenecarboxylic acids (pyromellitic, hemimellitic, trimellitic, o-phthalic, m-phthalic, p-phthalic, benzoic and salicylic acids and phenol). Heptanol was the most effective modifier in ion-exclusion chromatography for the improvement of peak shapes and a reduction in retention volumes for higher aliphatic carboxylic acids and benzenecarboxylic acids. Excellent simultaneous separation and relatively highly sensitive conductimetric detection for these C1-C7 aliphatic carboxylic acids were achieved on the TSKgel SCX column (150 x 6 mm I.D.) in 30 min using 0.5 mM sulfuric acid containing 0.025% heptanol as eluent. Excellent simultaneous separation and highly sensitive UV detection at 200 nm for these benzenecarboxylic acids were also achieved on the TSKgel SCX column in 30 min using 5 mM sulfuric acid containing 0.075% heptanol as eluent.

  7. Improved homopolymer separation to enable the application of H-1 NMR and HPLC for the determination of the reaction parameters of the graft copolymerization of acrylic acid onto starch

    NARCIS (Netherlands)

    Witono, Judy R.; Marsman, Jan Henk; Noordergraaf, Inge-Willem; Heeres, Hero J.; Janssen, Leon P. B. M.

    2013-01-01

    Graft copolymers of starch with acrylic acid are a promising green, bio based material with many potential applications. The grafting of acrylic acid onto cassava starch in an aqueous medium initiated by Fenton's reagent has been studied. Common grafting result parameters are add-on (yield) and

  8. Poly(acrylic acid) grafted montmorillonite as novel fillers for dental adhesives: synthesis, characterization and properties of the adhesive.

    Science.gov (United States)

    Solhi, Laleh; Atai, Mohammad; Nodehi, Azizollah; Imani, Mohammad; Ghaemi, Azadeh; Khosravi, Kazem

    2012-04-01

    This work investigates the graft polymerization of acrylic acid onto nanoclay platelets to be utilized as reinforcing fillers in an experimental dental adhesive. Physical and mechanical properties of the adhesive and its shear bond strength to dentin are studied. The effect of the modification on the stability of the nanoparticle dispersion in the dilute adhesive is also investigated. Poly(acrylic acid) (PAA) was grafted onto the pristine Na-MMT nanoclay (Cloisite(®) Na(+)) through the free radical polymerization of acylic acid in an aqueous media. The resulting PAA-g-nanoclay was characterized using FTIR, TGA and X-ray diffraction (XRD). The modified nanoclays were added to an experimental dental adhesive in different concentrations and the morphology of the nanoclay layers in the photocured adhesive matrix was studied using TEM and XRD. Shear bond strength of the adhesives containing different filler contents was tested on the human premolar teeth. The stability of nanoclay dispersion in the dilute adhesive was also studied using a separation analyzer. The results were then statistically analyzed and compared. The results confirmed the grafting reaction and revealed a partially exfoliated structure for the PAA-g-nanoclay. Incorporation of 0.2 wt.% of the modified nanoclay into the experimental adhesive provided higher shear bond strength. The dispersion stability of the modified nanoparticles in the dilute adhesive was also enhanced more than 25 times. Incorporation of the modified particles as reinforcing fillers into the adhesive resulted in higher mechanical properties. The nanofiller containing bonding agent also showed higher shear bond strength due to the probable interaction of the carboxylic acid functional groups on the surface of the modified particles with hydroxyapatite of dentin. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  9. Preparation, characterization and thermal properties of styrene maleic anhydride copolymer (SMA)/fatty acid composites as form stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet; Alkan, Cemil; Karaipekli, Ali; Oenal, Adem [Department of Chemistry, Gaziosmanpasa University, 60240, Tokat (Turkey)

    2008-02-15

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA) and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the major drawback of them, limiting their utility area in thermal energy storage. The use of fatty acids as form stable PCMs will increase their feasibilities in practical applications due to the reduced cost of the LHTES system. In this regard, a series of styrene maleic anhydride copolymer (SMA)/fatty acid composites, SMA/SA, SMA/PA, SMA/MA, and SMA/LA, were prepared as form stable PCMs by encapsulation of fatty acids into the SMA, which acts as a supporting material. The encapsulation ratio of fatty acids was as much as 85 wt.% and no leakage of fatty acid was observed even when the temperature of the form stable PCM was over the melting point of the fatty acid in the composite. The prepared form stable composite PCMs were characterized using optic microscopy (OM), viscosimetry and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the SMA was physically and chemically compatible with the fatty acids. In addition, the thermal characteristics such as melting and freezing temperatures and latent heats of the form stable composite PCMs were measured by using the differential scanning calorimetry (DSC) technique, which indicated they had good thermal properties. On the basis of all the results, it was concluded that form stable SMA/fatty acid composite PCMs had important potential for practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floors impregnated with a form stable PCM due to their satisfying thermal properties, easy preparation in desired dimensions, direct usability without needing additional encapsulation thereby eliminating the thermal resistance caused by the shell and, thus, reducing the cost of

  10. Controlled Release of Indomethacin from Smart Starch-Based Hydrogels Prepared Acrylic Acid and b-Cyclodextrin as a Nanocarrier

    Directory of Open Access Journals (Sweden)

    Hossein Ghasemzadeh Mohammadi

    2017-01-01

    Full Text Available Controlled release of drugs can reduce the undesired effects of drug level fluctuations, and diminish the side effects as well as improve the therapeutic outcome of the drugs. In recent year, the scope of the drug delivery systems has been greatly expanded by the development of various hydrogels. The present work has focused on the design of a pH sensitive drug delivery system (DDS based on starch, acrylic acid (AA and β-cyclodextrins for controlled delivery of indomethacin. The hydrogels were prepared via graft polymerization of acrylic acid (AA onto starch and β-cyclodextrins backbones by a free radical polymerization technique. Cyclodextrins are able to form water-soluble complexes with many lipophilic water-insoluble drugs. In aqueous solutions, the drug molecules located in the central cavity of the cyclodextrin are in a dynamic equilibrium with free drug molecules. The interaction of drug with the polymer was evidenced by FTIR spectroscopy and thermal gravimetric analysis (TGA. The morphology of the samples was examined by scanning electron microscopy (SEM. The results showed that the hydrogels have good porosity and provided high surface area for the loading and release of drugs. Drug release behavior was carried out at physiological conditions of phosphate buffer, pH 8. In basic pH (like the intestine medium the hydrogels released the indomethacin, but in acidic pH (like the stomach medium there was no tendency to drug release. By increasing the amount of cyclodextrin, the rate of drug loading and release increased due to the dynamic equilibrium and interaction between the loaded drug and the cyclodextrin. This study has demonstrated that the hydrogel matrices are potentially suitable for controlled-release systems.

  11. Graft copolymerization of acrylic acid to cassava starch-Evaluation of the influences of process parameters by an experimental design method

    NARCIS (Netherlands)

    Witono, J. R.; Noordergraaf, I. W.; Heeres, H. J.; Janssen, L. P. B. M.

    2012-01-01

    The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe2+/H2O2 redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this

  12. Detection system for Saccharomyces cerevisiae with phenyl acrylic acid decarboxylase gene (PAD1) and sulphur efflux gene (SSU1) by multiplex PCR.

    Science.gov (United States)

    Archana, K M; Anu-Appaiah, K A

    2017-10-16

    Production of wine with selected yeast strains is a common enological practice followed for the production of wine with desirable organoleptic properties and to guarantee the homogeneity of successive vintages. Sulphur dioxide tolerance and phenyl acrylic acid resistance are the enological traits essential for the survivability of the yeast during fermentation. The present study describes the detection of S. cerevisiae with enological traits, such as phenyl acrylic acid resistance and sulphur dioxide tolerance in a single test. Phenyl acrylic acid decarboxylase (PAD1) and sulphite efflux genes (SSU1) were detected by multiplex PCR, thus confirming the specificity of primers. A single cocktail of all reagents required for the simultaneous detection of both these genes was designed. The ready-to-use formulation optimized was stable at 4 and - 20 °C for 6 months. The amplification of phenyl acrylic acid decarboxylase and sulphite efflux genes, validated the suitability of the ready-to-use formulation for the detection of S. cerevisiae in food samples. The ready-to-use formulation optimized, minimizes the end user requirements for the detection of S. cerevisiae. Thus, the method was suitable for the identification of S. cerevisiae strains from a mixture of yeast prior to the sequencing analysis, thereby reducing the cost and time of screening.

  13. Chemically imaging the effects of the addition of nanofibrillated cellulose on the distribution of poly(acrylic acid) in poly(vinyl alcohol)

    Science.gov (United States)

    Craig Clemons; Julia Sedlmair; Barbara Illman; Rebecca Ibach; Carol Hirschmugl

    2013-01-01

    The distribution of poly(acrylic acid) (PAA) in model laminates of nanocellulose and poly(vinyl alcohol) (PVOH) was investigated by FTIR chemical imaging. The method was effective in spatially discerning the three components of the composite. PAA can potentially improve the performance of nanocellulose reinforced PVOH by not only crosslinking the PVOH matrix but also...

  14. In vivo and in vitro evaluation of the efficacy of a peracetic acid-based disinfectant for decontamination of acrylic resins.

    Science.gov (United States)

    Chassot, Ana Lúcia Campani; Poisl, Maria Inês Pereira; Samuel, Susana Maria Werner

    2006-01-01

    The purpose of this study was to assess the antimicrobial efficacy of a peracetic acid-based disinfectant for decontamination of heat-polymerized, chemically activated and microwave-polymerized acrylic resins. Resin plates were contaminated in vivo upon intraoral use by 10 volunteers for 7 nights and slabs were contaminated in vitro by contact with Bacillus subtilis and Bacillus stearothermophilus. The contaminated acrylic resin specimens were immersed in a 0.2% peracetic acid-based disinfectant (Sterilife; Lifemed) for 5 min or 10 min and placed in a BHI culture medium. After incubation at 37 degrees C for 48 h, bacterial growth was assessed by analyzing turbidity of the medium. For all types of acrylic resin, no turbidity of the medium was observed for any of the resin specimens immersed in the peracetic acid-based disinfectant for either 5 or 10 min. On the other hand, the media with specimens that were not immersed in the disinfectant (control) showed turbidity in 100% of the cases, indicating the presence of microorganisms in both tested conditions. In conclusion, immersion for at least 5 min in a 0.2% peracetic acid-based disinfectant promoted high-level disinfection of heat-polymerized, chemically activated and microwave-polymerized acrylic resins contaminated with either human saliva or Bacillus subtilis or Bacillus stearothermophilus.

  15. The use of dielectric spectroscopy for the characterisation of the precipitation of hydrophobically modified poly(acrylic-acid) with divalent barium ions

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2009-01-01

    The use of dielectric spectroscopy as a monitor for coagulation processes was investigated. Hydrophobically modified poly(acrylic-acid) polymers were used as model macromolecules and coagulated with barium ions. The coagulation process was quantified using a photometric dispersion analyser, thereby...

  16. A new coordination mode of (E)-3-(3-hydroxyl-phenyl)-acrylic acid in copper complex: Crystal structure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin; Zhou, Pei; Zheng, Chunying [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China); Li, Hui, E-mail: lihui@bit.edu [Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry, Beijing Institute of Technology, Beijing 100081 (China)

    2015-05-15

    A copper complex ([Cu(py){sub 2}(L){sub 2}]·2CH{sub 3}OH){sub n} (HL=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) (1) with acrylic acid ligand was synthesized and structurally analyzed by IR, elemental analysis, TGA and the single-crystal X-ray diffraction methods. It is the first time to find that phenolic hydroxyl of L coordinates to Cu(II). Complex 1 exhibits 1D chain by a double-bridge of ligands, and the 3D supramolecular framework in complex 1 is constructed by π–π stacking interactions and van der Waals Contacts among the 1D chains. The magnetic properties of complex 1 have been studied. - Graphical abstract: A copper complex based on (E)-3-(3-hydroxyl-phenyl)-acrylic acid in a novel coordinated way was synthesized and a ferromagnetic exchange interactions between neighboring Cu(II) ions has be achieved. - Highlights: • A new copper complex with acrylic acid ligand was synthesized and analyzed. • We find the phenolic hydroxyl of MCA ligand coordinates to metal ion firstly. • A ferromagnetic exchange interactions between Cu(II) ions has been achieved.

  17. Styrene exposure during the manufacturing of reinforced fiberglass pipe

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, K.E.

    1986-01-01

    Considering the large number of employees exposed to airborne styrene during the manufacturing of reinforced fiberglass pipe and the absence of appropriate information to define airborne styrene exposure and the resulting levels of urinary mandelic acid, it was necessary that these parameters be evaluated in an actual industrial setting in order to appropriately monitor and control health hazards in the work place. Styrene measurements were collected at eight work stations over a 5-year period at the world's largest manufacturer of styrenated reinforced fiberglass pipe. Pre- and post-shift urinary mandelic acid was measured for 16 employees for 3-consecutive days. The data obtained were statistically analyzed to determine the mean styrene exposure at each work station and the relationship between airborne styrene and pre-and post-shift urinary mandelic acid. The results of this study indicated that both the pre- and post-shift urinary mandelic acid measurements can be utilized to confirm human exposure to styrene. Post-shift measurements are more reflective of daily variations in styrene exposure, whereas pre-shift urinary mandelic acid was found to correlate best to the long-term airborne styrene concentrations (r = 0.787). The prediction equations of NIOSH and ACGIH for the arithmetic mean airborne styrene concentration from post-shift mandelic acid were not valid for the low levels of styrene exposure and urinary mandelic acid concentrations found in this study. Significant changes in the post-shift to pre-shift urinary mandelic acid concentrations were observed.

  18. A study on the swelling behavior of poly(acrylic acid) hydrogels obtained by electron beam crosslinking

    Energy Technology Data Exchange (ETDEWEB)

    Sheikh, N., E-mail: nasheikh@aeoi.org.i [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Jalili, L. [Polymer group, Technology and Engineering Department, Yazd University, Yazd (Iran, Islamic Republic of); Anvari, F. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Yazd (Iran, Islamic Republic of)

    2010-06-15

    Poly(acrylic acid) (PAA) hydrogels were prepared by using electron beam (EB) crosslinking of PAA homopolymer from its aqueous solutions. The swelling behavior of the hydrogels was studied as a function of the concentration of PAA solution, radiation dose, pH of the swelling medium and swelling time. Also the environmental pH effect on the water diffusion mode into hydrogels was investigated. These hydrogels clearly showed pH-sensitive swelling behavior with Fickian type of diffusion in the stomach-like pH medium (pH 1.3) and non-Fickian type in the intestine-like pH medium (pH 6.8).

  19. Thermoresponsive Photonic Crystal: Synergistic Effect of Poly(N-isopropylacrylamide)-co-acrylic Acid and Morpho Butterfly Wing.

    Science.gov (United States)

    Xu, Dongdong; Yu, Huanan; Xu, Qun; Xu, Guiheng; Wang, Kaixi

    2015-04-29

    In this work, we report a simple method to fabricate smart polymers engineered with hierarchical photonic structures of Morpho butterfly wing to present high performance that are capable of color tunability over temperature. The materials were assembled by combining functional temperature responsivity of poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAm-co-AAc) with the biological photonic crystal (PC) structure of Morpho butterfly wing, and then the synergistic effect between the functional polymer and the natural PC structure was created. Their cooperativity is instantiated in the phase transition of PNIPAm-co-AAc (varying with the change of temperature) that can alter the nanostructure of PCs, which further leads to the reversible spectrum response property of the modified hierarchical photonic structures. The cost-effective biomimetic technique presented here highlights the bright prospect of fabrication of more stimuli-responsive functional materials via coassembling smart polymers and biohierarchical structures, and it will be an important platform for the development of nanosmart biomaterials.

  20. Poly(acrylic acid)-directed synthesis of colloidally stable single domain magnetite nanoparticles via partial oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Altan, Cem L. [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Gurten, Berna [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sadza, Roel [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Yenigul, Elcin [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey); Sommerdijk, Nico A.J.M., E-mail: n.sommerdijk@tue.nl [Laboratory of Materials and Interface Chemistry & Soft Matter cryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Bucak, Seyda, E-mail: seyda@yeditepe.edu.tr [Department of Chemical Engineering, Yeditepe University, Istanbul 34755 (Turkey)

    2016-10-15

    Octahedral, single domain magnetite nanoparticles with average size of ~55 nm were synthesized through oxidative aging of a ferrous hydroxide (Fe(OH){sub 2}) precursor at high pH in water. The synthesis was also carried out in the presence of the hydrophilic polymer poly(acrylic acid). Presence of the polymer changed the particle morphology from octahedral to spherical while average size decreased to 40–50 nm. Although these particles have a tendency to precipitate due to their high magnetic moment, dispersions of these particles were obtained in the presence of this particular polymer which made the particles stable in water for several days making them suitable for various biotechnological applications such as cell separation owing to their low toxicity. - Highlights: • Stable, single domain magnetite nanoparticles are synthesized via partial oxidation. • Particles are readily stabilized in water by a biocompatible polymer. • Steric barrier is essential for the stabilization of large magnetite nanoparticles.

  1. Polydopamine-coated electrospun poly(vinyl alcohol)/poly(acrylic acid) membranes as efficient dye adsorbent with good recyclability.

    Science.gov (United States)

    Yan, Jiajie; Huang, Yunpeng; Miao, Yue-E; Tjiu, Weng Weei; Liu, Tianxi

    2015-01-01

    Free-standing poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) membranes with polydopamine (PDA) coating were prepared based on the combination of electrospinning and self-polymerization of dopamine. This is a facile, mild, controllable, and low-energy consumption process without any rigorous restriction to reactive conditions. Benefiting from the high specific surface area of electrospun membranes and the abundant "adhesive" functional groups of polydopamine, the as-prepared membranes exhibit efficient adsorption performance towards methyl blue with the adsorption capacity reaching up to 1147.6 mg g(-1). Moreover, compared to other nanoparticle adsorbents, the as-prepared self-standing membrane is highly flexible, easy to operate and retrieve, and most importantly, easy to elute, and regenerate, which enable its potential applications in wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Preparation and applications of novel fluoroalkyl end-capped acrylic acid oligomers/silica nanocomposites-encapsulated fullerenes.

    Science.gov (United States)

    Kasai, Remi; Yaegashi, Hideaki; Yokoyama, Hiroshi; Yamanaka, Masahiko; Sawada, Hideo

    2007-01-01

    Fluoroalkyl end-capped acrylic acid oligomers/fullerenes nanocomposites reacted smoothly with tetraethoxysilane (TEOS) and silica nanoparticles under alkaline conditions to give fluoroalkyl end-capped oligomers/silica composites-encapsulated fullerenes. Interestingly, these isolated fluorinated composites were found to afford nanometer size-controlled colloidal particles with a good dispersibility in a variety of organic solvents including water. More interestingly, these fluorinated silica nanocomposites-encapsulated fullerenes were applied to a new type of surface modification agent, and these nanocomposites were able to disperse well above the poly(methyl methacrylate) films to exhibit not only surface active property imparted by fluorine but also a unique characteristic related to fullerenes in the nanocomposites on the surface, effectively.

  3. BIODEGRADABLE PLASTICS FROM A MIXTURE OF LOW DENSITY POLYETHYLENE (LDPE AND CASSAVA STARCH WITH THE ADDITION OF ACRYLIC ACID

    Directory of Open Access Journals (Sweden)

    Susilawati Susilawati

    2013-05-01

    Full Text Available A research of preparation biodegradable plastics, from LDPE and cassava starch mixture with the addition of acrylic acid, had been conducted. This research purpose to  studied compatibility properties of the material and percent weight loss during the biodegradation test. Optimum weight loss (59,26% was showed after 60 days witches LDPE and starch composition ratio 6 : 4 (w/w  while tensile strength  equal to 0,38 Kgf/mm2.  SEM characterization showed that biodegradation has occurred by  formation of hole in the biodegradable plastic surface. DTA test gave Tg = 130 °C, Tm = 230 °C and Td = 370-450 °C while FT-IR analysis showed that the biodegradable plastics have a chemistry interaction.

  4. Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels for pH-sensitive photocatalytic degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Young-E; Jung, Gowun; Yun, Jumi; Kim, Hyung-Il, E-mail: hikim@cnu.ac.kr

    2013-10-01

    Graphical abstract: The photocatalytic removal of pollutants was improved by the two-step mechanism based on the adsorption of pollutants by hydrogel and the effective decomposition by combination of TiO{sub 2} and graphene oxide. -- Highlights: • pH sensitive PVA/PAAc hydrogels were prepared by radical polymerization and condensation reaction. • PVA/PAAc/TiO{sub 2}/graphene oxide nanocomposite hydrogels were used for treatment of basic waste water. • Photocatalytic acitivity of TiO{sub 2} was improved by incorporation of graphene oxide. • Photocatalytic decomposition by nanocomposite hydrogel was improved by increasing pH. -- Abstract: Poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were prepared using radical polymerization and condensation reaction for the photocatalytic treatment of waste water. Graphene oxide was used as an additive to improve the photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2} nanocomposite hydrogels. Both TiO{sub 2} and graphene oxide were immobilized in poly(vinyl alcohol)/poly(acrylic acid) hydrogel matrix for an easier recovery after the waste water treatment. The photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels was evaluated on the base of the degradation of pollutants by using UV spectrometer. The improved removal of pollutants was due to the two-step mechanism based on the adsorption of pollutants by nanocomposite hydrogel and the effective decomposition of pollutants by TiO{sub 2} and graphene oxide. The highest swelling of nanocomposite hydrogel was observed at pH 10 indicating that poly(vinyl alcohol)/poly(acrylic acid)/TiO{sub 2}/graphene oxide nanocomposite hydrogels were suitable as a promising system for the treatment of basic waste water.

  5. RAFT-Mediated Polymerization-Induced Self-Assembly of Poly(Acrylic Acid-b-Poly(Hexafluorobutyl Acrylate: Effect of the pH on the Synthesis of Self-Stabilized Particles

    Directory of Open Access Journals (Sweden)

    Jianhua Zhou

    2016-05-01

    Full Text Available This paper describes a very simple strategy towards self-stabilized poly(acrylic acid-block-poly(hexafluorobutyl acrylate (PAA-b-PHFBA block copolymer particles via reversible addition-fragmentation chain transfer (RAFT-mediated polymerization-induced self-assembly. Hexafluorobutyl acrylate (HFBA monomer conversion and number-average molar mass of PAA-b-PHFBA increased gradually with the increase in the pH value of the aqueous phase. When pH < 10, the molecular weight distributions of PAA-b-PHFBA were narrow, however, when the pH was raised to 11.55, PAA-b-PHFBA block copolymers had a broader distribution (ĐM = 1.82 with a serious trailing toward the low molecular weight. Furthermore, the morphology and size of PAA-b-PHFBA latex particles were measured by transmission electron microscopy and dynamic light scattering. The results indicated that the PAA-b-PHFBA latex particles had a clear spherical core-shell structure and the latex particles’ size increased with the increase of pH value.

  6. Two Players Make a Formidable Combination: In Situ Generated Poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) Cross-Linking Gel Polymer Electrolyte toward 5 V High-Voltage Batteries.

    Science.gov (United States)

    Ma, Yue; Ma, Jun; Chai, Jingchao; Liu, Zhihong; Ding, Guoliang; Xu, Gaojie; Liu, Haisheng; Chen, Bingbing; Zhou, Xinhong; Cui, Guanglei; Chen, Liquan

    2017-11-29

    Electrochemical performance of high-voltage lithium batteries with high energy density is limited because of the electrolyte instability and the electrode/electrolyte interfacial reactivity. Hence, a cross-linking polymer network of poly(acrylic anhydride-2-methyl-acrylic acid-2-oxirane-ethyl ester-methyl methacrylate) (PAMM)-based electrolyte was introduced via in situ polymerization inspired by "shuangjian hebi", which is a statement in a traditional Chinese Kungfu story similar to the synergetic effect of 1 + 1 > 2. A poly(acrylic anhydride) and poly(methyl methacrylate)-based system is very promising as electrolyte materials for lithium-ion batteries, in which the anhydride and acrylate groups can provide high voltage resistance and fast ionic conductivity, respectively. As a result, the cross-linking PAMM-based electrolyte possesses a significant comprehensive enhancement, including electrochemical stability window exceeding 5 V vs Li+/Li, an ionic conductivity of 6.79 × 10-4 S cm-1 at room temperature, high mechanical strength (27.5 MPa), good flame resistance, and excellent interface compatibility with Li metal. It is also demonstrated that this gel polymer electrolyte suppresses the negative effect resulting from dissolution of Mn2+ ions at 25 and 55 °C. Thus, the LiNi0.5Mn1.5O4/Li and LiNi0.5Mn1.5O4/Li4Ti5O12 cells using the optimized in situ polymerized cross-linking PAMM-based gel polymer electrolyte deliver stable charging/discharging profiles and excellent rate performance at room temperature and even at 55 °C. These findings suggest that the cross-linking PAMM is an intriguing candidate for 5 V class high-voltage gel polymer electrolyte toward high-energy lithium-on batteries.

  7. Selective catalytic oxidative-dehydrogenation of carboxylic acids-acrylate and crotonate formation at the Au/TiO2 interface.

    Science.gov (United States)

    McEntee, Monica; Tang, Wenjie; Neurock, Matthew; Yates, John T

    2014-04-02

    The oxidative-dehydrogenation of carboxylic acids to selectively produce unsaturated acids at the second and third carbons regardless of alkyl chain length was found to occur on a Au/TiO2 catalyst. Using transmission infrared spectroscopy (IR) and density functional theory (DFT), unsaturated acrylate (H2C═CHCOO) and crotonate (CH3CH═CHCOO) were observed to form from propionic acid (H3CCH2COOH) and butyric acid (H3CCH2CH2COOH), respectively, on a catalyst with ∼3 nm diameter Au particles on TiO2 at 400 K. Desorption experiments also show gas phase acrylic acid is produced. Isotopically labeled (13)C and (12)C propionic acid experiments along with DFT calculated frequency shifts confirm the formation of acrylate and crotonate. Experiments on pure TiO2 confirmed that the unsaturated acids were not produced on the TiO2 support alone, providing evidence that the sites for catalytic activity are at the dual Au-Ti(4+) sites at the nanometer Au particles' perimeter. The DFT calculated energy barriers between 0.3 and 0.5 eV for the reaction pathway are consistent with the reaction occurring at 400 K on Au/TiO2.

  8. Influence of the composition of hydroxypropyl cellulose/maleic acid-alt-styrene copolymer blends on their properties as matrix for drug release

    Directory of Open Access Journals (Sweden)

    2009-05-01

    Full Text Available Poly(carboxylic acid-polysaccharide compositions have been found suitable for obtaining drug formulations with controlled release, most formulations being therapeutically efficacious, stable, and non-irritant. The influence of the characteristics of the aqueous solutions from which the polymer matrix is prepared (i.e. the total concentration of polymer in solutions and the mixing ratio between the partners, hydroxypropyl cellulose, HPC and maleic acid-alternating-styrene copolymer, MAc-alt-S on the kinetics of some drugs release in acidic environment (pH = 2 has been followed by ‘in vitro’ dissolution tests. It has been established that the kinetics of procaine hydrochloride release from HPC/MAc-alt-S matrix depends on its composition; the diffusion exponent, n is close to 0.5 for matrices where one of the components is in large excess and n~0.02 for middle composition range. The lower value of diffusion exponent for middle composition range could be caused by the so called ‘burst effect’, therefore the kinetic evaluation is difficult.

  9. Synthesis and luminescent properties of the novel poly(ethylene-co-acrylic acid) films based on surface modification with lanthanide (Eu3+, Tb3+) complexes

    Science.gov (United States)

    Wu, Yuewen; Chu, Yang; Yu, Zhenjiang; Hao, Haixia; Wu, Qingyao; Xie, Hongde

    2017-10-01

    Two kinds of novel fluorescent films have been successfully synthesized by surface modification on the poly(ethylene-co-acrylic acid) films using the lanthanide (Eu3+, Tb3+) complexes. The process consists of three steps: conversion of carboxylic acid groups on the surface of the poly(ethylene-co-acrylic acid) films to acid chloride groups, synthesis of the lanthanide complexes bearing amino groups, and amidation to form the modified films. To characterize the modified films, Fourier transform infrared, thermogravimetric analysis, static water contact angle measurements and photoluminescence tests have been employed. Fourier transform infrared verifies the successful preparation of the lanthanide complexes and the modified poly(ethylene-co-acrylic acid) films. These films can emit strong characteristic red and green light under UV light excitation. In addition, the films both have short lifetime (1.14 ms and 1.21 ms), high thermal stability (Td = 408 °C and 411 °C) and, compared with unmodified ones, increased hydrophilicity. All these results suggest that the modified films have potential application as luminescent materials under high temperature.

  10. Diffusion coefficient, porosity measurement, dynamic and equilibrium swelling studies of Acrylic acid/Polyvinyl alcohol (AA/PVA hydrogels

    Directory of Open Access Journals (Sweden)

    Nazar Mohammad Ranjha

    2015-06-01

    Full Text Available Objective of the present work was to synthesize hydrogels of acrylic acid/polyvinyl alcohol (AA/PVA by free radical polymerization by using glutaradehyde (GA as crosslinkers. The hydrogels were evaluated for swelling, diffusion coefficient and network parameters like the average molecular weight between crosslink’s, polymer volume fraction in swollen state, number of repeating units between crosslinks and crosslinking density by using Flory-Huggins theory. It was found that the degree of swelling of AA/PVA hydrogels increases greatly within the pH range 5-7. The gel fraction and porosity increased by increasing the concentration of AA or PVA. Increase in degree of crosslinking, decreased the porosity and inverse was observed in gel fraction. Selected samples were loaded with metoprolol tartrate. Drug release was studied in USP hydrochloric acid solution of pH 1.2 and phosphate buffer solutions of pH 5.5 and 7.5. Various kinetics models like zero order, first order, Higuchi and Peppas model were used for in vitro kinetic studies. The results showed that the drug release followed concentration dependent effect (First order kinetics with non-Fickian diffusion. FTIR and SEM used to study the structure, crystallinity, compatibility, thermal stability and morphology of prepared and drug loaded hydrogels respectively.

  11. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2014-09-03

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  12. Vinyl ether/acrylic acid terpolymer hydrogels synthesized by {gamma}-radiation: characterization, thermosensitivity and pH-sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Guemuesderelioglu, Menemse [Hacettepe University, Chemical Engineering Department, Beytepe, Ankara 06532 (Turkey)]. E-mail: menemse@hacettepe.edu.tr; Topal, Ilknur Uysal [Hacettepe University, Chemical Engineering Department, Beytepe, Ankara 06532 (Turkey)

    2005-08-01

    The radiation copolymerization of hydrophilic ethylene glycol vinyl ether (EGVE), hydrophobic butyl vinyl ether (BVE) and/or acidic comonomer acrylic acid (AA) was realized in the presence of crosslinking agent diethylene glycol divinyl ether (DEGDVE). The swelling studies which were carried out at 4 and 37 deg. C in phosphate buffer solution (PBS, pH 7.4) showed that equilibrium swelling ratios of the hydrogels (except EGVE homopolymer hydrogel) decreases with increasing temperature and swelling process obeys non-Fickian diffusion mechanism. The pH-dependent swelling behaviour of the hydrogels was examined in buffered solutions at various pHs. The swelling process is reversible and pH-dependent for the AA-containing hydrogel. While this hydrogel shows a fully hydrated form at pH>6; it extensively dehydrates below pH 6. The gels are stable after the repeated swelling experiments. The molecular structure of the hydrogels was studied by Fourier Transform Infrared Spectroscopy and their thermal behaviour was investigated by Differential Scanning Calorimetry and Thermal Gravimetric Analysis. The surface and cross-section structures of the gels were examined by a Scanning Electron Microscope.

  13. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Science.gov (United States)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong; Khil, Myung-Seob; Lee, Deok-Won; Ahn, Sung-Jun

    2015-01-01

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  14. Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization.

    Science.gov (United States)

    Wang, Yawen; Song, Xiohui; Wang, Hong; Chen, Hongyu

    2015-07-09

    We present a template-free method for "polymerizing" nanoparticles into long chains without side branches. A variety of nanoparticles are encapsulated in polystyrene-block-poly(acrylic acid) (PSPAA) shells and then used as monomers for their self-assembly. Spherical PSPAA micelles upon acid treatment are known to assemble into cylindrical micelles. Exploiting this tendency, the core-shell nanoparticles are induced to aggregate, coalesce, and then transform into long chains. When more than one type of nanoparticles are used, random and block "copolymers" of nanoparticles can be obtained. Detailed procedures are reported for the PSPAA encapsulation of nanoparticles, homo- and co-polymerization of the core-shell nanoparticles, separation and purification of the resulting nanoparticle chains. Transformations of single-line chains into double- and triple-line chains are also presented. The synergy between the polymer shell and the embedded nanoparticles leads to an unusual chain-growth polymerization mode, giving long nanoparticle chains that are distinct from the products of the traditional step-growth aggregation process.

  15. Radiation-induced controlled polymerization of acrylic acid by RAFT and RAFT-MADIX methods in protic solvents

    Science.gov (United States)

    Sütekin, S. Duygu; Güven, Olgun

    2018-01-01

    The kinetic investigation of one-pot synthesis of poly(acrylic acid) (PAA) prepared via gamma radiation induced controlled polymerization was reported. PAA homopolymers were prepared by Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization in the presence of trithiocarbonate-based chain transfer agent (CTA) 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) and also by Reversible Addition-Fragmentation/Macromolecular Design by Inter-change of Xanthates (RAFT/MADIX) polymerization in the presence of a xanthate based CTA O-ethyl-S-(1-methoxycarbonyl) ethyl dithiocarbonate (RA1). The polymerizations were performed at room temperature by the virtue of ionizing radiation. Protic solvents were used for the RAFT polymerization of AA considering environmental profits. The linear first-order kinetic plot, close control of molecular weight by the monomer/CTA molar ratio supported that the polymerization proceeds in a living fashion. The linear increase in molecular weight with conversion monitored by Size Exclusion Chromatography (SEC) is another proof of controlling of polymerization. [Monomer]/[RAFT] ratio and conversion was controlled to obtain PAA in the molecular weight range of 6900-35,800 with narrow molecular weight distributions. Reaction kinetics and effect of the amount of RAFT agent were investigated in detail. Between two different types of CTA, trithiocarbonate based DDMAT was found to be more efficient in terms of low dispersity (Đ) and linear first-order kinetic behavior for the radiation induced controlled synthesis of PAA homopolymers.

  16. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Khil, Myung-Seob [Chonbuk National University, Jeonju (Korea, Republic of); Lee, Deok-Won [Maxillofacial Surgery Dental Hospital, Seoul (Korea, Republic of); Ahn, Sung-Jun [JADAM Co., LTD., Seogwipo (Korea, Republic of)

    2015-01-15

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  17. Optimal Design for Reactivity Ratio Estimation: A Comparison of Techniques for AMPS/Acrylamide and AMPS/Acrylic Acid Copolymerizations

    Directory of Open Access Journals (Sweden)

    Alison J. Scott

    2015-11-01

    Full Text Available Water-soluble polymers of acrylamide (AAm and acrylic acid (AAc have significant potential in enhanced oil recovery, as well as in other specialty applications. To improve the shear strength of the polymer, a third comonomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS, can be added to the pre-polymerization mixture. Copolymerization kinetics of AAm/AAc are well studied, but little is known about the other comonomer pairs (AMPS/AAm and AMPS/AAc. Hence, reactivity ratios for AMPS/AAm and AMPS/AAc copolymerization must be established first. A key aspect in the estimation of reliable reactivity ratios is design of experiments, which minimizes the number of experiments and provides increased information content (resulting in more precise parameter estimates. However, design of experiments is hardly ever used during copolymerization parameter estimation schemes. In the current work, copolymerization experiments for both AMPS/AAm and AMPS/AAc are designed using two optimal techniques (Tidwell-Mortimer and the error-in-variables-model (EVM. From these optimally designed experiments, accurate reactivity ratio estimates are determined for AMPS/AAm (rAMPS = 0.18, rAAm = 0.85 and AMPS/AAc (rAMPS = 0.19, rAAc = 0.86.

  18. Denitrification with acrylonitrile as a substrate using pure bacteria cultures isolated from acrylonitrile-butadiene-styrene wastewater.

    Science.gov (United States)

    Wang, C C; Lee, C M

    2001-04-01

    This study attempted to isolate and identify the denitrifying bacteria that utilize acrylonitrile as a substrate from acrylonitrile-butadiene-styrene (ABS) resin wastewater. The performance of the denitrifying bacteria for treating different initial acrylonitrile concentrations was also investigated under anoxic conditions. The results showed that seven strains of denitrifying bacteria that can use acrylonitrile or acrylic acid as a substrate were isolated from the denitrification tank of a wastewater treatment plant in a ABS resin manufacturing plant and a lab-scale anoxic granular activated carbon-fluidized bed. The bacteria strains Acidovorax facilis B and Pseudomonas nautica could utilize acrylonitrile up to 279 mg/l as a substrate for denitrification. For complete nitrate removal, an adequate supply of acrylonitrile was necessary. Under the assumption that the acrylic acid would be completely removed, the removal of 1 mg/l nitrate by A. facilis B or P. nautica, about 0.64-0.74 mg/l acrylonitrile or 0.87-1 mg/l acrylic acid was needed. Because strains A. facilis B and P. nautica could utilize acrylonitrile for denitrification, they are expected to play an important role in the treatment of acrylonitrile in the wastewater treatment plant (denitrification and nitrification processes) and lab-scale granular activated carbon-fluidized bed.

  19. Synthesis and Swelling Behavior of pH-Sensitive Semi-IPN Superabsorbent Hydrogels Based on Poly(acrylic acid Reinforced with Cellulose Nanocrystals

    Directory of Open Access Journals (Sweden)

    Lim Sze Lim

    2017-11-01

    Full Text Available pH-sensitive poly(acrylic acid (PAA hydrogel reinforced with cellulose nanocrystals (CNC was prepared. Acrylic acid (AA was subjected to chemical cross-linking using the cross-linking agent MBA (N,N-methylenebisacrylamide with CNC entrapped in the PAA matrix. The quantity of CNC was varied between 0, 5, 10, 15, 20, and 25 wt %. X-ray diffraction (XRD data showed an increase in crystallinity with the addition of CNC, while rheology tests demonstrated a significant increase in the storage modulus of the hydrogel with an increase in CNC content. It was found that the hydrogel reached maximum swelling at pH 7. The potential of the resulting hydrogels to act as drug carriers was then evaluated by means of the drug encapsulation efficiency test using theophylline as a model drug. It was observed that 15% CNC/PAA hydrogel showed the potential to be used as drug carrier system.

  20. Surface Structure of Acrylate Polymer Adhesives.

    Science.gov (United States)

    Roy, Sandra; Freiberg, Stephan; Leblanc, Claude; Hore, Dennis K

    2017-02-28

    Total internal reflection infrared (IR) absorption and visible-IR sum-frequency spectroscopies were used to study the role of acrylic acid in the evolution of surface structure in a poly(butyl acrylate)-based pressure-sensitive adhesive during the drying process. By monitoring these spectral responses and calculating the heterospectral correlation coefficients, we established that acrylic acid alters the nature of the molecular interactions at the surface. In the absence of acrylic acid, butyl acrylate orientation is driven by the packing of the polymer as the water evaporates. When acrylic acid is present, a rapid ordering of the copolymer takes place as a result of favorable hydrogen-bonding interactions with the surface.

  1. Injectable biocompatible and biodegradable pH-responsive hollow particle gels containing poly(acrylic acid): the effect of copolymer composition on gel properties.

    Science.gov (United States)

    Halacheva, Silvia S; Adlam, Daman J; Hendow, Eseelle K; Freemont, Tony J; Hoyland, Judith; Saunders, Brian R

    2014-05-12

    The potential of various pH-responsive alkyl (meth)acrylate ester- and (meth)acrylic acid-based copolymers, including poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) and poly(n-butyl acrylate-co-methacrylic acid) (PBA-MAA), to form pH-sensitive biocompatible and biodegradable hollow particle gel scaffolds for use in non-load-bearing soft tissue regeneration have been explored. The optimal copolymer design criteria for preparation of these materials have been established. Physical gels which are both pH- and redox-sensitive were formed only from PMMA-AA copolymers. MMA is the optimal hydrophobic monomer, whereas the use of various COOH-containing monomers, e.g., MAA and AA, will always induce a pH-triggered physical gelation. The PMMA-AA gels were prepared at physiological pH range from concentrated dispersions of swollen, hollow, polymer-based particles cross-linked with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP). A linear relationship between particle swelling ratios, gel elasticity, and ductility was observed. The PMMA-AA gels with lower AA contents feature lower swelling ratios, mechanical strengths, and ductilities. Increasing the swelling ratio (e.g., through increasing AA content) decreased the intraparticle elasticity; however, intershell contact and gel elasticity were found to increase. The mechanical properties and performance of the gels were tuneable upon varying the copolymers' compositions and the structure of the cross-linker. Compared to PMMA-AA/CYS, the PMMA-AA/DTP gels were more elastic and ductile. The biodegradability and cytotoxicity of the new hollow particle gels were tested for the first time and related to their composition, mechanical properties, and morphology. The new PMMA-AA/CYS and PMMA-AA/DTP gels have shown good biocompatibility, biodegradability, strength, and interconnected porosity and therefore have good potential as a tissue repair agent.

  2. Synthesis of perm-selective membranes by grafting acrylic acid into air-irradiated Teflon-FEP films

    Energy Technology Data Exchange (ETDEWEB)

    Bozzi, Annick; Chapiro, Adolphe

    1988-01-01

    Grafting acrylic acid into air-irradiated Teflon-FEP films was investigated. Pre-irradiation doses ranged from 0.5 to 10 kGy. Grafting occurred at 45 or 60/sup 0/C. Homopolymerization inhibitors, ferrous ions or methylene blue, were added to the system. It was found that after completion of the reaction, within 40-100 min, membranes were obtained with very low electric resistivities. The influence of added inhibitors, pre-irradiation dose and grafting temperature was studied. From the results it is concluded that the initiating centers in air-irradiated Teflon-FEP are, on the one hand, peroxides of structure POOP', in which P is a polymeric radical and P' a small fragment, and on the other hand trapped PO/sub 2/sup(center dot) radicals. The latter only react after losing their oxygen. In the presence of polymerization inhibitors, initiation involves a redox process which reduces the overall activation energy.

  3. Plasma-induced grafting of acrylic acid on bentonite for the removal of U(VI) from aqueous solution

    Science.gov (United States)

    Hongshan, ZHU; Shengxia, DUAN; Lei, CHEN; Ahmed, ALSAEDI; Tasawar, HAYAT; Jiaxing, LI

    2017-11-01

    Fabrication of reusable adsorbents with satisfactory adsorption capacity and using environment-friendly preparation processes is required for the environment-related applications. In this study, acrylic acid (AA) was grafted onto bentonite (BT) to generate an AA-graft-BT (AA-g-BT) composite using a plasma-induced grafting technique considered to be an environment-friendly method. The as-prepared composite was characterized by scanning electron microscopy, x-ray powder diffraction, thermal gravity analysis, Fourier transform infrared spectroscopy and Barrett-Emmett-Teller analysis, demonstrating the successful grafting of AA onto BT. In addition, the removal of uranium(VI) (U(VI)) from contaminated aqueous solutions was examined using the as-prepared composite. The influencing factors, including contact time, pH value, ionic strength, temperature, and initial concentration, for the removal of U(VI) were investigated by batch experiments. The experimental process fitted best with the pseudo-second-order kinetic and the Langmuir models. Moreover, thermodynamic investigation revealed a spontaneous and endothermic process. Compared with previous adsorbents, AA-g-BT has potential practical applications in treating U(VI)-contaminated solutions.

  4. Ultrasensitive Biosensor for the Detection of Vibrio cholerae DNA with Polystyrene-co-acrylic Acid Composite Nanospheres

    Science.gov (United States)

    Rahman, Mahbubur; Heng, Lee Yook; Futra, Dedi; Ling, Tan Ling

    2017-08-01

    An ultrasensitive electrochemical biosensor for the determination of pathogenic Vibrio cholerae ( V. cholerae) DNA was developed based on polystyrene-co-acrylic acid (PSA) latex nanospheres-gold nanoparticles composite (PSA-AuNPs) DNA carrier matrix. Differential pulse voltammetry (DPV) using an electroactive anthraquninone oligonucleotide label was used for measuring the biosensor response. Loading of gold nanoparticles (AuNPs) on the DNA-latex particle electrode has significantly amplified the faradaic current of DNA hybridisation. Together with the use of a reported probe, the biosensor has demonstrated high sensitivity. The DNA biosensor yielded a reproducible and wide linear response range to target DNA from 1.0 × 10-21 to 1.0 × 10-8 M (relative standard deviation, RSD = 4.5%, n = 5) with a limit of detection (LOD) of 1.0 × 10-21 M ( R 2 = 0.99). The biosensor obtained satisfactory recovery values between 91 and 109% ( n = 3) for the detection of V. cholerae DNA in spiked samples and could be reused for six consecutive DNA assays with a repeatability RSD value of 5% ( n = 5). The electrochemical biosensor response was stable and maintainable at 95% of its original response up to 58 days of storage period.

  5. A drug-loaded gel based on polyelectrolyte complexes of poly (acrylic acid) with poly (vinylpyrrolidone) and chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Jin Shuping [Key Laboratory of Resources and Environmental Chemistry of West China, Department of Chemistry, Hexi University, Zhangye 734000 (China); Liu Mingzhu, E-mail: mzliu@lzu.edu.cn [Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China); Chen Shilan [Department of Chemistry, Chongqing University of Science and Technology, Chongqing 401331 (China); Gao Chunmei [Department of Chemistry and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000 (China)

    2010-10-01

    A drug-loaded gel (CSPP) based on ionic crosslinked chitosan (CS) and polyelectrolyte complexes of poly (acrylic acid) (PAA) with poly (vinylpyrrolidone) (PVP) was prepared by dropping CS solution containing suitable amount of PVP into PAA and trisodium citrate co-existing gelling solution. The surface and cross-section morphology of the gel was observed using scanning electron microscopy, and the observation showed that the CSPP gel had more compact structure than CS gel. In vitro release profiles of model drug from the CSPP gel, which was prepared under different conditions, were investigated in simulative gastric fluid (pH 1.8) using an UV/vis spectrophotometer. The results showed that the rapid release of the model was restrained due to the complex of PVP and PAA, and the CSPP gel could serve as a suitable candidate in drug delivery system such as the site-specific controlled release of the drug in stomach. In addition, the release mechanism of drug was analyzed by fitting the amount of drug released into Peppa's potential equation.

  6. Bacterial cellulose/acrylic acid hydrogel synthesized via electron beam irradiation: accelerated burn wound healing in an animal model.

    Science.gov (United States)

    Mohamad, Najwa; Mohd Amin, Mohd Cairul Iqbal; Pandey, Manisha; Ahmad, Naveed; Rajab, Nor Fadilah

    2014-12-19

    Natural polymer-based hydrogels are of interest to health care professionals as wound dressings owing to their ability to absorb exudates and provide hydration for healing. The aims of this study were to develop and characterize bacterial cellulose/acrylic acid (BC/AA) hydrogels synthesized by electron beam irradiation and investigate its wound healing potential in an animal model. The BC/AA hydrogels were characterized by SEM, tensile strength, water absorptivity, and water vapor transmission rate (WVTR). The cytotoxicity of the hydrogels was investigated in L929 cells. Skin irritation and wound healing properties were evaluated in Sprague-Dawley rats. BC/AA hydrogels had a macroporous network structure, high swelling ratio (4000-6000% at 24h), and high WVTR (2175-2280 g/m(2)/day). The hydrogels were non-toxic in the cell viability assay. In vivo experiments indicated that hydrogels promoted faster wound-healing, enhanced epithelialization, and accelerated fibroblast proliferation compared to that in the control group. These results suggest that BC/AA hydrogels are promising materials for burn dressings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Preparation and swelling behavior of a novel self-assembled β-cyclodextrin/acrylic acid/sodium alginate hydrogel.

    Science.gov (United States)

    Huang, Zhanhua; Liu, Shouxin; Zhang, Bin; Wu, Qinglin

    2014-11-26

    A novel biodegradable β-cyclodextrin/acrylic acid/sodium alginate (CSA) hydrogel with a three-dimensional network structure was self-assembled by inverse suspension copolymerization. The CSA resin was pH sensitive and had good water absorption properties in pH 6-8 buffer solutions. At a β-CD:AA:SA mass ratio of 1:9:3 the CSA water absorbency was found to be 1403 g/g and the CSA hydrogel strength was 4.968 N. In 0.005-0.1 mol/L chloride salt and sulfate salt solutions the CSA water absorbencies increased as follows: NaCl>KCl>MgCl2>CaCl2>FeCl3, and Na2SO4>K2SO4>FeSO4>Al2(SO4)3, respectively. The release of water from the CSA hydrogel occurred slowly over 120 h. The biodegradation efficiency of the resin reached 85.3% for Lentinula edodes. The super water absorbency, good salt resistance and excellent water retention properties of CSA make it suitable for application as an agricultural water retention agent in saline soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Biocompatibility of poly(ethylene glycol) and poly(acrylic acid) interpenetrating network hydrogel by intrastromal implantation in rabbit cornea.

    Science.gov (United States)

    Zheng, Luo Luo; Vanchinathan, Vijay; Dalal, Roopa; Noolandi, Jaan; Waters, Dale J; Hartmann, Laura; Cochran, Jennifer R; Frank, Curtis W; Yu, Charles Q; Ta, Christopher N

    2015-10-01

    We evaluated the biocompatibility of a poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) interpenetrating network hydrogel designed for artificial cornea in a rabbit model. PEG/PAA hydrogel measuring 6 mm in diameter was implanted in the corneal stroma of twelve rabbits. Stromal flaps were created with a microkeratome. Randomly, six rabbits were assigned to bear the implant for 2 months, two rabbits for 6 months, two rabbits for 9 months, one rabbit for 12 months, and one rabbit for 16 months. Rabbits were evaluated monthly. After the assigned period, eyes were enucleated, and corneas were processed for histology and immunohistochemistry. There were clear corneas in three of six rabbits that had implantation of hydrogel for 2 months. In the six rabbits with implant for 6 months or longer, the corneas remained clear in four. There was a high rate of epithelial defect and corneal thinning in these six rabbits. One planned 9-month rabbit developed extrusion of implant at 4 months. The cornea remained clear in the 16-month rabbit but histology revealed epithelial in-growth. Intrastromal implantation of PEG/PAA resulted in a high rate of long-term complications. © 2015 Wiley Periodicals, Inc.

  9. Synthesis of a Nanostructured Molecularly Imprinted Acrylic acid-Based Network Copolymer as a Solid Sorbentforthe Quercetinextraction

    Directory of Open Access Journals (Sweden)

    A. Amiri

    2014-07-01

    Full Text Available A straightforward approach for the extraction of the quercetin was carried out by a nanoporous molecularly imprinted acrylic acid-based network copolymer as asolid sorbent. This technique involves a molecular template (quercetin which is surrounded by functional monomers and are subsequently co-polymerized in the presence of an excess of the cross linkers. In this process, three-dimensional binding sites are generated that are complementary to the quercetin template in terms of size, shape and position of functional groups. After removal of the imprinting quercetin template, the nanostructured polymer can therefore specifically recognize and re-bind the same or structurally very similar molecules. The synthesized MIP by bulk polymerization was exhibited a good tendency to absorb the quercetin template in a solid phase extraction (SPE system. The prepared MIP achieved a binding capacity of 169 mg/grfor the quercetin in acetonitrile-water (1:1 v/v solvent. Imaging by scanning electron microscope (SEM was carried out to determine the surface morphology of the prepared MIP.

  10. Determination of Monomers Reactivity Ratios in Ethyl Acrylate-Methacrylic Acid Copolymerization by Off-Line 1H NMR

    Directory of Open Access Journals (Sweden)

    Samaneh Ashenagar

    2017-03-01

    Full Text Available The physical, chemical and mechanical properties of polymer systems depend on the micro-structural characteristics of their macromolecular chains. Along with the most characteristic kinetic parameters in copolymerization reactions are the reactivity ratios, which give a clear idea of the average composition and the monomer sequence distribution in copolymer systems. This research studies the solution radical copolymerization of methacrylic acid (MAA-ethyl acrylate (EA system at low conversion with 2,2'-azobisisobutyronitrile (AIBN as thermal initiator at 60°C in deuterated dimethyl sulfoxide (DMSO-d6 as a reaction solvent. In this case, the monomer reactivity ratios were determined using linear off-line 1H nuclear magnetic resonance spectroscopy (1H NMR methods such as Mayo-Louis, Finemann-Ross, Inverted Finemann-Ross , Ezrielev-Brokhina-Roskin, Joshi-Joshi, Kelen-Tudos, extended Kelen- Tudos, Mao-Huglin at low and high conversions. The next estimation process in off-line 1H NMR methods were performed by applying techniques based on ordinary least square (OLS and generalized least square (GLS. The results showed that the GLS approach compared to the OLS increased regression coefficients (R2 and the order of magnitude of parameter variances obtained from GLS was many times lower than that obtained from OLS. In addition, the monomer reactivity ratios obtained by the Mao-Huglin method and the GLS approach showed the best linear estimation.

  11. A quantitative study of the enzymatic activity of horseradish peroxidase at a planar poly(acrylic acid) brush.

    Science.gov (United States)

    Reichhart, Christian; Czeslik, Claus

    2010-02-01

    The enzymatic activity of horseradish peroxidase (HRP) has been quantified at a planar poly(acrylic acid) (PAA) brush. A PAA brush is known to exhibit an unusual protein binding affinity, since proteins adsorb at low ionic strength only. At elevated ionic strengths of a few 100 mM proteins desorb, and the PAA brush becomes largely protein resistant. In this study, HRP was used to catalyze the oxidation of Amplex Red to resorufin by hydrogen peroxide. The fluorescence of resorufin was recorded using a microplate reader. As compared to a bare silica surface, the enzymatic activity of HRP is higher by more than one order of magnitude at a PAA brush. This increase results from a higher degree of adsorption and a reasonable preservation of the HRP activity. Upon adsorption at a PAA brush from a 20 mU/mL (0.1 microg/mL) solution, the molecular enzymatic activity of HRP is reduced to about 11%. However, when a HRP molecule is desorbed from a PAA brush by increasing the ionic strength, a gain of the molecular enzymatic activity by only 52% can be observed. Overall, this study illustrates the potential applicability of a PAA brush as a biocompatible material coating.

  12. Preparation of anion exchanger by amination of acrylic acid grafted polypropylene nonwoven fiber and its ion-exchange property.

    Science.gov (United States)

    Park, Hyun-Ju; Na, Choon-Ki

    2006-09-01

    To develop the polymeric adsorbent that possess anionic exchangeable function, PP-g-AA-Am fibers were prepared by photoinduced grafting of acrylic acid (AA) onto polypropylene (PP) nonwoven fibers and subsequent conversion of carboxyl group in grafted AA to an amine (Am) group by reaction with diethylene triamine (DETA). The amination of grafted AA increased with increase in the degree of grafting, the reaction time and temperature of the chemical modification process. Catalytic effect of metal chlorides such as AlCl(3) and FeCl(3) on the amination of grafted AA was significant but not essential to lead the amination. FT-IR and solid (13)C NMR data indicate that amine group was introduced into PP-g-AA fiber through amide linkage between grafted AA and DETA. The anion exchange capacity of PP-g-AA-Am fiber increased with increase in the degree of amination, but reached maximum value at about 60% amination of 150% grafted AA. PP-g-AA-Am fiber showed much higher maximum capacity for PO(4)-P and a similar capacity for NO(3)-N compared to commercial anion resins. Furthermore, the PP-g-AA-Am fiber also has adsorption ability for cations because of unaminated residual carboxyl group.

  13. Effects Of Environmental Factors On The Dispersion Behavior Of Iron Oxide In Aqueous Solutions With Poly Acrylic Acid

    Directory of Open Access Journals (Sweden)

    Lee E.-H.

    2015-06-01

    Full Text Available After preparing aqueous suspensions from magnetite particles with a poly-acrylic acid, we investigated the effects of several experimental parameters. We characterized the stability of the suspensions using visual inspection, sedimentation, adsorption, and thermal stability of the dispersant. The dispersion stability is affected by the solution pH, the concentrations of magnetite particles, the molecular weight, the concentration of the dispersants, and the temperature. The stability of the suspensions increased as the concentration of the dispersant and the temperature increased. In terms of the molecular weights of the dispersant, the suspensions with dispersant of low-molecular weight (1800 were more stable than those of high-molecular weight (250000 at room temperature. However, at high temperature the suspensions with high-molecular weight showed stability. The adsorption efficiency of the dispersant was very low. The dispersant of high-molecular weight showed a higher thermal integrity than that of low-molecular weight. From this work, we obtained the optimum conditions for stable aqueous suspensions of magnetite particles.

  14. Superabsorbent nanocomposite synthesis of cellulose from rice husk grafted poly(acrylate acid-co-acrylamide)/bentonite

    Science.gov (United States)

    Helmiyati; Abbas, G. H.; Kurniawan, S.

    2017-04-01

    Superabsorbent nanocomposite synthesis of cellulose rice husk as the backbone with free radical polymerization method in copolymerization grafted with acrylic acid and acrylamide monomer. The cellulose was isolated from rice husk with mixture of toluene and ethanol and then hemicellulose and lignin were removed by using potassium hydroxide 4% and hydrogen peroxide 2%. The obtained cellulose rendement was 37.85%. The functional group of lignin analyzed by FTIR spectra was disappeared at wavenumber 1724 cm-1. Crystal size of the obtained isolated cellulose analyzed by XRD diffraction pattern was 34.6 nm, indicated the nanocrystal structure. Copolymerization was performed at temperature of 70°C with flow nitrogen gas. Initiator and crosslinking agent used were potassium persulfate and N‧N-methylene-bis-acrylamide. The swelling capacity of water and urea showed the results was quite satisfactory, the maximum swelling capacity in urea and water were 611.700 g/g and 451.303 g/g, respectively, and can be applied in agriculture to absorb water and urea fertilizer.

  15. Preparation of mesoporous poly (acrylic acid)/SiO2 composite nanofiber membranes having adsorption capacity for indigo carmine dye

    Science.gov (United States)

    Xu, Ran; Jia, Min; Li, Fengting; Wang, Hongtao; Zhang, Bingru; Qiao, Junlian

    2012-03-01

    Mesoporous poly (acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber membranes functionalized with mercapto groups were fabricated by a sol-gel electrospinning method, and their adsorption capacity for indigo carmine was investigated. The membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray powder diffraction (XRD), and nitrogen adsorption-desorption measurement. SEM and TEM observation results showed that the PAA/SiO2 fibers had diameters between 400-800 nm and mesopores with an average pore size of 3.88 nm. The specific surface area of the mesoporous nanofiber membranes was 514.89 m2/g. The characteristic peaks for mercapto group vibration in FTIR and Raman spectra demonstrated that the mercapto groups have been incorporated into the silica skeleton. The adsorption isotherm data of indigo carmine on the membranes fit well with Redlich-Peterson model, and the maximum adsorption capacity calculated was 523.11 mg/g. It was found that the removal rate of indigo carmine by the membranes reached a maximum of 98% in 90 min and the adsorption kinetics followed a pseudo-second-order model. The high adsorption capacity of PAA/SiO2 nanofiber membrane makes it a promising adsorbent for indigo carmine removal from the wastewater.

  16. Highly hydrophilic ultra-high molecular weight polyethylene powder and film prepared by radiation grafting of acrylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Honglong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xu, Lu; Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Pang, Lijuan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Hu, Jiangtao; Wang, Mouhua [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong, E-mail: wuguozhong@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-09-30

    Highlights: • Hydrophilic UHMWPE powder and film were obtained by γ-ray pre-irradiation grafting of AA. • A low concentration of AA solution was used for surface modification of UHMWPE. • A small grafting yield of AA sufficiently improved hydrophilicity of UHMWPE powder and film. - Abstract: The surface properties of ultra-high molecular weight polyethylene (UHMWPE) are very important for its use in engineering or composites. In this work, hydrophilic UHMWPE powder and film were prepared by γ-ray pre-irradiation grafting of acrylic acid (AA) and further neutralization with sodium hydroxide solution. Variations in the chemical structure, grafting yield and hydrophilicity were investigated and compared. FT-IR and XPS analysis results showed that AA was successfully grafted onto UHMWPE powder and film; the powder was more suitable for the grafting reaction in 1 wt% AA solution than the film. Given a dose of 300 kGy, the grafting yield of AA was ∼5.7% for the powder but ∼0.8% for the film under identical conditions. Radiation grafting of a small amount of AA significantly improved the hydrophilicity of UHMWPE. The water contact angle of the UHMWPE-g-PAA powder with a grafting yield of AA at ∼5.7% decreased from 110.2° to 68.2°. Moreover, the grafting powder (UHMWPE-g-PAA) exhibited good dispersion ability in water.

  17. Graphene oxide/poly(acrylic acid)/gelatin nanocomposite hydrogel: experimental and numerical validation of hyperelastic model.

    Science.gov (United States)

    Faghihi, Shahab; Karimi, Alireza; Jamadi, Mahsa; Imani, Rana; Salarian, Reza

    2014-05-01

    Owing to excellent thermal and mechanical properties, graphene-based nanomaterials have recently attracted intensive attention for a wide range of applications, including biosensors, bioseparation, drug release vehicle, and tissue engineering. In this study, the effects of graphene oxide nanosheet (GONS) content on the linear (tensile strength and strain) and nonlinear (hyperelastic coefficients) mechanical properties of poly(acrylic acid) (PAA)/gelatin (Gel) hydrogels are evaluated. The GONS with different content (0.1, 0.3, and 0.5 wt.%) is added into the prepared PAA/Gel hydrogels and composite hydrogels are subjected to a series of tensile and stress relaxation tests. Hyperelastic strain energy density functions (SEDFs) are calibrated using uniaxial experimental data. The potential ability of different hyperelastic constitutive equations (Neo-Hookean, Yeoh, and Mooney-Rivlin) to define the nonlinear mechanical behavior of hydrogels is verified by finite element (FE) simulations. The results show that the tensile strength (71%) and elongation at break (26%) of composite hydrogels are significantly increased by the addition of GONS (0.3 wt.%). The experimental data is well fitted with those predicted by the FE models. The Yeoh material model accurately defines the nonlinear behavior of hydrogels which can be used for further biomechanical simulations of hydrogels. This finding might have implications not only for the improvement of the mechanical properties of composite hydrogels but also for the fabrication of polymeric substrate materials suitable for tissue engineering applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    Directory of Open Access Journals (Sweden)

    M. Golzar

    2014-01-01

    Full Text Available Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA prevents iron nanoparticles from forming large flocs that may cause sedimentation and so increases transport distance of the nanoparticles. In this study, the transport of iron oxide nanoparticles (Fe3O4 stabilized with PAA in a one-dimensional porous media (column was investigated. The slurries with concentrations of 20,100 and 500 (mg/L were injected into the bottom of the column under hydraulic gradients of 0.125, 0.375, and 0.625. The results obtained from experiments were compared with the results obtained from numerical solution of advection-dispersion equation based on the classical colloid filtration theory (CFT. The experimental and simulated breakthrough curves showed that CFT is able to predict the transport and fate of iron oxide nanoparticles stabilized with PAA (up to concentration 500 ppm in a porous media.

  19. Chitosan-modified poly(acrylonitrile-co-acrylic acid) nanofibrous membranes for the immobilization of concanavalin A.

    Science.gov (United States)

    Che, Ai-Fu; Liu, Zhen-Mei; Huang, Xiao-Jun; Wang, Zhen-Gang; Xu, Zhi-Kang

    2008-12-01

    Lectin affinity membranes have been receiving much attention for the separation and detection of various glycoconjugates. In this work, we present a simple and efficient method for the preparation of lectin affinity nanofibrous membranes. Chitosan-modified poly(acrylonitrile-co-acrylic acid) (PANCAA) nanofibrous membranes were first prepared by a coupling reaction between the primary amino groups of chitosan and the carboxyl groups of PANCAA electrospun membranes. Surface characterizations by attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM) confirm the chemical and morphological changes of the studied nanofibrous membranes. Fluorescence-labeled concanavalin A (FL-Con A) was then immobilized on these membranes via noncovalent binding. Analyses by fluorescence spectrophotometer (FS) and confocal laser scanning microscopy (CLSM) reveal that the immobilization of Con A onto the modified nanofibrous membranes has been successfully achieved on the basis of the electrostatic interaction and the specific recognition between Con A and chitosan. The results show that the amount of adsorbed FL-Con A increases dramatically with the increasing coupling degree of chitosan (CDC) on the nanofibrous membrane. Moreover, Con A immobilized on the chitosan-modified nanofibrous membranes (CMNMs) can remain relatively stable at pH 5.3. Therefore, it is believed that this work may provide a new kind of material for affinity application.

  20. Characterization and Antimicrobial Property of Poly(Acrylic Acid Nanogel Containing Silver Particle Prepared by Electron Beam

    Directory of Open Access Journals (Sweden)

    Jong-Bae Choi

    2013-05-01

    Full Text Available In this study, we developed a one step process to synthesize nanogel containing silver nanoparticles involving electron beam irradiation. Water-soluble silver nitrate powder is dissolved in the distilled water and then poly(acrylic acid (PAAc and hexane are put into this silver nitrate solution. These samples are irradiated by an electron beam to make the PAAc nanogels containing silver nanoparticles (Ag/PAAc nanogels. The nanoparticles were characterized by scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS. In addition, the particle size and zeta-potential were confirmed by a particle size analyzer (PSA. The antibacterial properties of the nanogels were evaluated by paper diffusion test. The Ag/PAAc nanogels had an antibacterial effect against Escherichia coli and Staphylococcus aureus. The nanogels also demonstrated a good healing effect against diabetic ulcer. The size of the Ag/PAAc nanogels decreased with increasing irradiation doses, and the absolute value of the zeta potential increased with increasing irradiation doses. Also, the Ag/PAAc nanogels exhibited good antibacterial activity against both Gram-negative and Gram-positive bacteria. In in vivo wound healing, the Ag/PAAc nanogels have a good healing effect.

  1. Synthesis of bioadhesive poly(acrylic acid) nano- and microparticles using an inverse emulsion polymerization method for the entrapment of hydrophilic drug candidates.

    Science.gov (United States)

    Kriwet, B; Walter, E; Kissel, T

    1998-12-04

    Bioadhesive latices of water-swollen poly(acrylic acid) nano-and microparticles were synthesized using an inverse (W/O) emulsion polymerization method. They are stabilized by a co-emulsifier system consisting of SpanTM 80 and TweenTM 80 dispersed in aliphatic hydrocarbons. The initial polymerization medium contains emulsion droplets and inverse micelles which solubilize a part of the monomer solution. The polymerization is initiated by free radicals, and particle dispersions with a narrow size distribution are obtained. The particle size is dependent on the type of radical initiator used. With water-soluble initiators, for example ammonium persulfate, microparticles were obtained in the size range of 1 to 10 micrometer indicating that these microparticles originate from the emulsion droplets since the droplet sizes of the W/O emulsion show similar distribution. When lipophilic radical initiators, such as azobis-isobutyronitrile, are used, almost exclusively nanoparticles are generated with diameters in the range of 80 to 150 nm, due to the limited solubility of oligomeric poly(acrylic acid) chains in the lipophilic continuous phase. These poly(acrylic acid) micro- and nanoparticles yielded excellent bioadhesive properties in an in-vitro assay and may, therefore, be suitable for the encapsulation of peptides and other hydrophilic drugs.

  2. DMFC Performance of Polymer Electrolyte Membranes Prepared from a Graft-Copolymer Consisting of a Polysulfone Main Chain and Styrene Sulfonic Acid Side Chains

    Directory of Open Access Journals (Sweden)

    Nobutaka Endo

    2016-08-01

    Full Text Available Polymer electrolyte membranes (PEMs for direct methanol fuel cell (DMFC applications were prepared from a graft-copolymer (PSF-g-PSSA consisting of a polysulfone (PSF main chain and poly(styrene sulfonic acid (PSSA side chains with various average distances between side chains (Lav and side chain lengths (Lsc. The polymers were synthesized by grafting ethyl p-styrenesulfonate (EtSS on macro-initiators of chloromethylated polysulfone with different contents of chloromethyl (CM groups, and by changing EtSS content in the copolymers by using atom transfer radical polymerization (ATRP. The DMFC performance tests using membrane electrode assemblis (MEAs with the three types of the PEMs revealed that: a PSF-g-PSSA PEM (SF-6 prepared from a graft copolymer with short average distances between side chains (Lav and medium Lsc had higher DMFC performance than PEMs with long Lav and long Lsc or with short Lav and short Lsc. SF-6 had about two times higher PDmax (68.4 mW/cm2 than Nafion® 112 at 30 wt % of methanol concentration. Furthermore, it had 58.2 mW/cm2 of PDmax at 50 wt % of methanol concentration because of it has the highest proton selectivity during DMFC operation of all the PSF-g-PSSA PEMs and Nafion® 112.

  3. Styrene maleic acid-encapsulated RL71 micelles suppress tumor growth in a murine xenograft model of triple negative breast cancer.

    Science.gov (United States)

    Martey, Orleans; Nimick, Mhairi; Taurin, Sebastien; Sundararajan, Vignesh; Greish, Khaled; Rosengren, Rhonda J

    2017-01-01

    Patients with triple negative breast cancer have a poor prognosis due in part to the lack of targeted therapies. In the search for novel drugs, our laboratory has developed a second-generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71), that exhibits potent in vitro cytotoxicity. To improve the clinical potential of this drug, we have encapsulated it in styrene maleic acid (SMA) micelles. SMA-RL71 showed improved biodistribution, and drug accumulation in the tumor increased 16-fold compared to control. SMA-RL71 (10 mg/kg, intravenously, two times a week for 2 weeks) also significantly suppressed tumor growth compared to control in a xenograft model of triple negative breast cancer. Free RL71 was unable to alter tumor growth. Tumors from SMA-RL71-treated mice showed a decrease in angiogenesis and an increase in apoptosis. The drug treatment also modulated various cell signaling proteins including the epidermal growth factor receptor, with the mechanisms for tumor suppression consistent with previous work with RL71 in vitro. The nanoformulation was also nontoxic as shown by normal levels of plasma markers for liver and kidney injury following weekly administration of SMA-RL71 (10 mg/kg) for 90 days. Thus, we report clinical potential following encapsulation of a novel curcumin derivative, RL71, in SMA micelles.

  4. Styrene maleic acid-encapsulated paclitaxel micelles: antitumor activity and toxicity studies following oral administration in a murine orthotopic colon cancer model.

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Norton, Samuel E; Highton, Andrew J; Taurin, Sebastien; Kemp, Roslyn A; Greish, Khaled

    2016-01-01

    Oral administration of paclitaxel (PTX), a broad spectrum anticancer agent, is challenged by its low uptake due to its poor bioavailability, efflux through P-glycoprotein, and gastrointestinal toxicity. We synthesized PTX nanomicelles using poly(styrene-co-maleic acid) (SMA). Oral administration of SMA-PTX micelles doubled the maximum tolerated dose (60 mg/kg vs 30 mg/kg) compared to the commercially available PTX formulation (PTX [Ebewe]). In a murine orthotopic colon cancer model, oral administration of SMA-PTX micelles at doses 30 mg/kg and 60 mg/kg reduced tumor weight by 54% and 69%, respectively, as compared to the control group, while no significant reduction in tumor weight was observed with 30 mg/kg of PTX (Ebewe). In addition, toxicity of PTX was largely reduced by its encapsulation into SMA. Furthermore, examination of the tumors demonstrated a decrease in the number of blood vessels. Thus, oral delivery of SMA-PTX micelles may provide a safe and effective strategy for the treatment of colon cancer.

  5. Styrene maleic acid micelles as a nanocarrier system for oral anticancer drug delivery – dual uptake through enterocytes and M-cells

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Müller, Philipp; Taurin, Sebastien; Greish, Khaled

    2015-01-01

    Drug delivery systems could potentially overcome low bioavailability and gastrointestinal toxicity, which are the major challenges for the development of oral anticancer drugs. Herein, we demonstrate the ability of styrene maleic acid (SMA) nanomicelles encapsulating epirubicin to traverse in vitro and ex vivo models of the intestinal epithelium without affecting the tissue integrity. Further, SMA micelles encapsulating a fluorescent dye dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) showed twofold higher accumulation in the liver and spleen, 15-fold higher accumulation in the tumor, and sixfold higher accumulation in the lung as compared with the free DiI, following oral administration in a mice xenograft breast cancer model. Additionally, SMA micelles showed colocalization with microfold (M)-cells and accumulation in Peyer’s patches, which together confirms the M-cell mediated uptake and transport of SMA micelles. Our results indicate that SMA micelles, showing dual uptake by enterocytes and M-cells, are a potential tool for safe oral anticancer drug delivery. PMID:26229468

  6. Styrene maleic acid micelles as a nanocarrier system for oral anticancer drug delivery - dual uptake through enterocytes and M-cells.

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Müller, Philipp; Taurin, Sebastien; Greish, Khaled

    2015-01-01

    Drug delivery systems could potentially overcome low bioavailability and gastrointestinal toxicity, which are the major challenges for the development of oral anticancer drugs. Herein, we demonstrate the ability of styrene maleic acid (SMA) nanomicelles encapsulating epirubicin to traverse in vitro and ex vivo models of the intestinal epithelium without affecting the tissue integrity. Further, SMA micelles encapsulating a fluorescent dye dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) showed twofold higher accumulation in the liver and spleen, 15-fold higher accumulation in the tumor, and sixfold higher accumulation in the lung as compared with the free DiI, following oral administration in a mice xenograft breast cancer model. Additionally, SMA micelles showed colocalization with microfold (M)-cells and accumulation in Peyer's patches, which together confirms the M-cell mediated uptake and transport of SMA micelles. Our results indicate that SMA micelles, showing dual uptake by enterocytes and M-cells, are a potential tool for safe oral anticancer drug delivery.

  7. The Use of Styrene Maleic Acid Nanomicelles Encapsulating the Synthetic Cannabinoid Analog WIN55,212-2 for the Treatment of Cancer.

    Science.gov (United States)

    Xian, Susan; Parayath, Neha N; Nehoff, Hayley; Giles, Niroshini M; Greish, Khaled

    2015-09-01

    Synthetic cannabinoid WIN55,212-2 (WIN) has shown a promise as an anticancer agent but causes psychoactive side-effects. In the present study, nano-micelles of styrene maleic acid (SMA)-conjugated WIN were synthesized to reduce side-effects and increase drug efficacy. SMA-WIN micelles were characterised and their in vitro cytotoxic effect was compared to that of free WIN against triple-negative breast cancer (MDA-MB-231), hormone receptor-positive breast cancer (MCF-7) and castration-resistant prostate cancer (PC3) cell lines. SMA-WIN micelles were synthesised with a ~15% loading, 132.7 nm average diameter, -0.0388 mV charge, and pH-dependent release rate. A dose-dependent inhibition of cell growth was observed in all three cell lines treated with both free and micellar WIN, with both formulations demonstrating equal cytotoxicity. SMA-WIN demonstrated characteristics theorized to improve in vivo drug biodistribution. Potent cytotoxicity was found against breast and prostate cancer cells in vitro, showing promise as a novel treatment against breast and prostate cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  8. Antimicrobial efficacy of gentamicin-loaded acrylic bone cements with fusidic acid or clindamycin added

    NARCIS (Netherlands)

    Neut, D; Hendriks, JGE; van Horn, [No Value; Kowalski, RSZ; van der Mei, HC; Busscher, HJ

    The increasing gentamicin resistance among bacteria in septic joint arthroplasty has stimulated interest in adding a second antibiotic into gentamicin-loaded bone cement. A first aim of this in vitro study is to investigate whether addition of fusidic acid or clindamycin to gentamicin-loaded bone

  9. (Z)-2-Hydr-oxy-3-(4-methoxy-phen-yl)acrylic acid.

    Science.gov (United States)

    Ouyang, Hui; Tian, Qi-Jian; Jiang, Yong-Dong; Tian, Chun-Lian

    2009-11-28

    In the structure of the title compound, C(10)H(10)O(4), inversion dimers linked by pairs of O-H⋯O hydrogen bonds link the carboxylic acid groups. Further O-H⋯O links cross-link the dimers into sheets running along the b-axis direction.

  10. Investigation on Au-nano incorporated pH-sensitive (itaconic acid/acrylic acid/triethylene glycol) based polymeric biocompatible hydrogels.

    Science.gov (United States)

    Sakthivel, M; Franklin, D S; Sudarsan, S; Chitra, G; Guhanathan, S

    2017-06-01

    The pH-sensitive gold nano hydrogel based on itaconic acid, acrylic acid and triethylene glycol (GIAT) has been prepared by free radical polymerization viz. organic solventless approach with different monomer ratios. The nature of bonding and structural identification of GIAT hydrogels were characterized by FT-IR spectroscopy. The surface morphology of gold gel was examined using scanning electron microscopy (SEM). In addition, transmission electron microscopy (TEM) was used to identify the size of gold nano particles. The in vitro biocompatibility of GIAT hydrogel has been evaluated in 3T3 fibroblast cell lines. The obtained results show that gold nano particle incorporated hydrogel possess ~99% of cell proliferation. Followed by, the impact of gold nano particles on swelling, surface morphology was studied. The consecutive preparation of hydrogel, effect of different pH conditions, and stoichiometry of monomeric units have also been discussed. The degree of swelling was measured in carbonate buffer solutions for 24h period with varying pH such as 1.2, 6.0, 7.4 and 10.0. The obtained results showed that the stoichiometry of itaconic acid and gold nano particles plays an essential role in modifying the nature of GIAT polymeric hydrogels. In conclusion, promising Au-nano incorporated pH-sensitive bio polymeric hydrogels were prepared and characterized. The unique properties of these Au-nano hydrogel make them attractive use in biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Magnetic pH-responsive poly(methacrylic acid-co-acrylic acid)-co-polyvinylpyrrolidone magnetic nano-carrier for controlled delivery of fluvastatin.

    Science.gov (United States)

    Amoli-Diva, Mitra; Pourghazi, Kamyar; Mashhadizadeh, Mohammad Hossein

    2015-02-01

    A novel pH-responsive polymer, poly(methacrylic acid-co-acrylic acid)-co-polyvinyl-pyrrolidone (polymeric nano-carrier) was synthesized and used for encapsulation of 3-aminopropyl triethoxysilane modified Fe3O4 nanoparticles to prepare a new magnetic nano-carrier. The loading and release characteristics of both polymeric and magnetic nano-carriers were investigated using fluvastatin as the model drug. The loading behavior of the carriers was studied by varying concentration of fluvastatin in aqueous medium at 25°C and their release was followed spectrophotometrically (at 304 nm) at 37°C in three different solutions (buffered at pH1.2, 5.5 and 7.2) to simulate gastric and intestine medium. The effect of different parameters on the release of fluvastatin such as the amount of methacrylic acid monomer, cross-linker amount, initiator amount, and magnetic nanoparticles content was also studied. Considering the release kinetics and mechanism of the magnetic nanocarrier besides swelling behavior study of the polymeric nano-carrier reveal Fickian pattern and diffusion controlled mechanism for delivery of fluvastatin. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Electron beam curing of dimer acid-based urethane acrylates for pressure sensitive adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takashi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Takeda, Satoe; Shiraishi, Katsutoshi

    1995-03-01

    Polyester urethane diacrylate prepolymers prepared from dimer acids (DUA) were cured with low energy electron beams to investigate adhesive properties of cured films. Among various type monomers added, monofunctional methacrylates such as isobornyl methacrylate (IBXMA) were effective for higher peel strength cured films although the dose-to-cure for the mixtures increased to 100 kGy or more. The increase in the molecular weight of prepolymers resulted in lower curing rates but higher peel strength. Aging tests up to 80degC for four weeks proved good stability in peel strength of the stored products. (author).

  13. Oral drug delivery system based on interpolymer complex formation between poly(acrylic acid) and poly(vinyl pyrrolidone-co-vinyl acetate)

    CSIR Research Space (South Africa)

    Germishuizen, A

    2005-07-01

    Full Text Available as it passes through the acidic medium of the stomach (pH 1-2) square4 The drug is released upon entering the basic medium of the lower intestines (pH 6.2-7.4) square4 The delivery system should thus be pH- sensitive square4 A system based on inter... system based on interpolymer complex formation between poly(acrylic acid) and poly(vinyl pyrrolidone-co-vinyl acetate) 13 July 2005 André Germishuizen Supporting the Manufacturing and Materials Industry in its quest for global competitiveness CSIR...

  14. Cytotoxicity and metal ions removal using antibacterial biodegradable hydrogels based on N-quaternized chitosan/poly(acrylic acid).

    Science.gov (United States)

    Mohamed, Riham R; Elella, Mahmoud H Abu; Sabaa, Magdy W

    2017-05-01

    Physically crosslinked hydrogels resulted from interaction between N,N,N-trimethyl chitosan chloride (N-Quaternized Chitosan) (NQC) and poly(acrylic acid) (PAA) were synthesized in different weight ratios (3:1), (1:1) and (1:3) taking the following codes Q3P1, Q1P1 and Q1P3, respectively. Characterization of the mentioned hydrogels was done using several analysis tools including; FTIR, XRD, SEM, TGA, biodegradation in simulated body fluid (SBF) and cytotoxicity against HepG-2 liver cancer cells. FTIR results proved that the prepared hydrogels were formed via electrostatic and H-bonding interactions, while XRD patterns proved that the prepared hydrogels -irrespective to their ratios- were more crystalline than both matrices NQC and PAA. TGA results, on the other hand, revealed that Q1P3 hydrogel was the most thermally stable compared to the other two hydrogels (Q3P1 and Q1P1). Biodegradation tests in SBF proved that these hydrogels were more biodegradable than the native chitosan. Examination of the prepared hydrogels for their potency in heavy metal ions removal revealed that they adsorbed Fe (III) and Cd (II) ions more than chitosan, while they adsorbed Cr (III), Ni (II) and Cu (II) ions less than chitosan. Moreover, testing the prepared hydrogels as antibacterial agents towards several Gram positive and Gram negative bacteria revealed their higher antibacterial activity as compared with NQC when used alone. Evaluating the cytotoxic effect of these hydrogels on an in vitro human liver cancer cell model (HepG-2) showed their good cytotoxic activity towards HepG-2. Moreover, the inhibition rate increased with increasing the hydrogels concentration in the culture medium. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Chitosan-decorated polystyrene-b-poly(acrylic acid) polymersomes as novel carriers for topical delivery of finasteride.

    Science.gov (United States)

    Caon, Thiago; Porto, Ledilege Cucco; Granada, Andréa; Tagliari, Monika Piazzon; Silva, Marcos Antonio Segatto; Simões, Cláudia Maria Oliveira; Borsali, Redouane; Soldi, Valdir

    2014-02-14

    In view of the fact that the oral administration of finasteride (FIN) has resulted in various undesirable systemic side effects, the topical application of polystyrene and poly(acrylic acid)-based polymersomes (underexplored system) was investigated. Undecorated PS139-b-PAA17 and PS404-b-PAA63 vesicles (C3 and C7, respectively) or vesicles decorated with chitosan samples of different molecular weight (C3/CS-oligo, C7/CS-oligo, C3/CS-37 and C7/CS-37) were prepared by the co-solvent self-assembly method and characterized by small-angle X-ray scattering,transmission electron microscopy and dynamic light scattering techniques. In vitro release experiments and ex vivo permeation using Franz diffusion cells were carried out (through comparison with hydroethanolic finasteride solution). The ideal system should provide high finasteride retention in the dermis and epidermis while allowing some control of the drug release. The particle size and in vitro release were negatively correlated with the permeation coefficient and skin retention in both the epidermis and dermis. The findings that the longest lag time was obtained for the hydroethanolic drug solution and lowest permeation for the systems able to release the drug faster support the hypothesis that nanostructured systems may be required to enhance the penetration and permeation of the drug. Chitosan-decorated polymersomes interacted more strongly with the skin components than non-decorated samples, probably due to the positive surface charge, which increased the FIN retention and reduced the lag time. C7 polymersomes decorated with chitosan were more appropriate for topical applications (high retention in the dermis and epidermis and controlled drug delivery). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Nanoclays reinforced glass ionomer cements: dispersion and interaction of polymer grade (PG) montmorillonite with poly(acrylic acid).

    Science.gov (United States)

    Fareed, Muhammad A; Stamboulis, Artemis

    2014-01-01

    Montmorillonite nanoclays (PGV and PGN) were dispersed in poly(acrylic acid) (PAA) for utilization as reinforcing filler in glass ionomer cements (GICs). Chemical and physical interaction of PAA and nanoclay (PGV and PGN) was studied. PAA–PGV and PAA–PGN solutions were prepared in different weight percent loadings of PGV and PGN nanoclay (0.5-8.0 wt%) via exfoliation-adsorption method. Characterization was carried out by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and fourier transform infrared (FTIR) spectroscopy. XRD results of PAA–PGN demonstrated that the interlayer space expanded from 12.83 to 16.03 Å indicating intercalation whereas the absence of the peak at d(001) in PAA–PGV indicated exfoliation. XPS scans of PGV and PGN nanoclays depicted the main peak of O 1s photoelectron due to Si–O–M (M = Mg, Al, Fe) whereas, Si–O–Al linkages were identified by Si 2p or Si 2s and Al 2p or Al 2s peaks. The disappearance of the Na peak confirmed that PAA molecules exchanged sodium ions present on surface of silicate layers and significantly reduced the electrostatic van-der-Waals forces between silicate plates resulting in intercalation or exfoliation. FTIR spectra of PAA–nanoclay suspensions demonstrated the presence of a new peak at 1,019 cm(-1) associated with Si–O– stretching vibrations which increased with increasing nanoclays concentration. Information concerning the dispersion of nanoclay in PAA aqueous solutions, chemical reaction and increase interlayer space in montmorillonite nanoclay is particularly useful regarding dispersion and reinforcement of nanoclay in PAA.

  17. Synthesis of Potato Starch-Acrylic-Acid Hydrogels by Gamma Radiation and Their Application in Dye Adsorption

    Directory of Open Access Journals (Sweden)

    Md. Murshed Bhuyan

    2016-01-01

    Full Text Available Several kinds of acrylic-acid-grafted-starch (starch/AAc hydrogels were prepared at room temperature (27°C by applying 5, 10, 15, 20, and 25 kGy of gamma radiation to 15% AAc aqueous solutions containing 5, 7.5, and 15% of starch. With increment of the radiation dose, gel fraction became higher and attained the maximum (96.5% at 15 kGy, above which the fraction got lowered. On the other hand, the gel fraction monotonically increased with the starch content. Swelling ratios were lower for the starch/AAc hydrogels prepared with higher gamma-ray doses and so with larger starch contents. Significant promotions of the swelling ratios were demonstrated by hydrolysis with NaOH: 13632±10% for 15 kGy radiation-dosed [5% starch/15% AAc] hydrogel, while the maximum swelling ratio was ~200% for those without the treatment. The authors further investigated the availability of the starch/AAc hydrogel as an adsorbent recovering dye waste from the industrial effluents by adopting methylene blue as a model material; the hydrogels showed high dye-capturing coefficients which increase with the starch ratio. The optimum dye adsorption was found to be 576 mg per g of the hydrogel having 7.5 starch and 15% AAc composition. Two kinetic models, (i pseudo-first-order and (ii pseudo-second-order kinetic models, were applied to test the experimental data. The latter provided the best correlation of the experimental data compared to the pseudo-first-order model.

  18. Otoacoustic emission sensitivity to exposure to styrene and noise.

    Science.gov (United States)

    Sisto, R; Cerini, L; Gatto, M P; Gherardi, M; Gordiani, A; Sanjust, F; Paci, E; Tranfo, G; Moleti, A

    2013-11-01

    The ototoxic effect of the exposure to styrene is evaluated, also in the presence of simultaneous exposure to noise, using otoacoustic emissions as biomarkers of mild cochlear damage. Transient-evoked and distortion product otoacoustic emissions were recorded and analyzed in a sample of workers (15 subjects) exposed to styrene and noise in a fiberglass manufacturing facility and in a control group of 13 non-exposed subjects. Individual exposure monitoring of the airborne styrene concentrations was performed, as well as biological monitoring, based on the urinary concentration of two styrene metabolites, the Mandelic and Phenylglyoxylic acids. Noise exposure was evaluated using wearable phonometers, and hearing loss with pure tone audiometry. Due to their different job tasks, one group of workers was exposed to high noise and low styrene levels, another group to higher styrene levels, close to the limit of 20 ppm, and to low noise levels. A significant negative correlation was found between the otoacoustic emission levels and the concentration of the styrene urinary metabolites. Otoacoustic emissions, and particularly distortion products, were able to discriminate the exposed workers from the controls, providing also a rough estimate of the slope of the dose-response relation between otoacoustic levels and styrene exposure.

  19. Neurobehavioral effects of acute styrene exposure in fiberglass boatbuilders

    Energy Technology Data Exchange (ETDEWEB)

    Letz, R.; Mahoney, F.C.; Hershman, D.L.; Woskie, S.; Smith, T.J. (Mount Sinai School of Medicine, New York, NY (USA))

    1990-11-01

    A field investigation of the effects of acute exposure to styrene among fiberglass boatbuilders was performed. Personal samples of styrene in breathing zone air and postshift urinary mandelic acid were collected for 105 workers exposed and not exposed to styrene in 6 fiberglass boatbuilding companies in New England. Three tests from the computerized Neurobehavioral Evaluation System (NES) were performed by the subjects in the morning before exposure to styrene, near midday, and at the end of the work day. Duration of exposure averaged 2.9 years (SD = 4.6), 8-hour TWA styrene exposure averaged 29.9 ppm (SD = 36.2), and urinary mandelic acid averaged 347 mg/g creatinine (SD = 465). Regression analyses indicated a statistically significant relationship between postshift performance on the Symbol-Digit test and both acute styrene exposure and mandelic acid. Other analyses comparing workers exposed to less than 50 ppm and greater than 50 ppm styrene also showed a significant effect on Symbol-Digit performance. All three NES tests showed test-retest correlation coefficients above .80, and ease of use for collection of neurobehavioral data under field conditions was demonstrated.

  20. Incorporation of bactericidal poly-acrylic acid modified copper iodide particles into adhesive resins.

    Science.gov (United States)

    Sabatini, Camila; Mennito, Anthony S; Wolf, Bethany J; Pashley, David H; Renné, Walter G

    2015-05-01

    This study aimed to investigate incorporation of polyacrylic acid (PAA) coated copper iodide (CuI) nanoparticles into dental adhesives, and to evaluate for the first time, their antibacterial properties, bond strength and cytotoxicity. PAA-CuI nanoparticles were synthesized and incorporated into commercially available adhesives Optibond XTR (1.0mg/ml) and XP Bond (0.5 and 1.0mg/ml). The antibacterial properties of experimental and control specimens were evaluated (n=8), after ageing for 18h or 1 year, against Streptococcus mutans (1×10(8)cells/ml). Bond strength to human dentine of the control and experimental adhesives was evaluated by shear bond strength (n=10). For cytotoxicity evaluation, HGF cells were cultured with gingival fibroblast media and exposed to control and experimental adhesive blends (n=3). An MTT cell viability assay was used to assess cell metabolic function. A one-way analysis of variance followed by Tukey's test was used for data analysis. Significantly greater antibacterial properties were demonstrated for PAA-CuI containing adhesives after ageing for 18h or 1 year relative to all control groups. A reduction in Streptococcus mutans viable cell count of 99.99%, 99.99% and 79.65% was shown for XP Bond - 0.5mg/ml, XP Bond - 1.0mg/ml and Optibond XTR - 1.0mg/ml PAA-CuI after ageing for 18h, and 99.99% for both XP Bond - 0.5mg/ml and XP Bond - 1.0mg/ml PAA-CuI after ageing for 1 year. No significant variations in shear bond strength or cytotoxicity were detected between the experimental resins and their corresponding controls. PAA-CuI nanoparticles are an effective additive to adhesive blends as it renders them antibacterial without adversely affecting their bond strength or cytotoxicity. The incorporation of PAA-coated copper iodide particles into adhesive resins renders the adhesive antibacterial to S. mutans for at least 1 year in vitro. This may prevent or delay bacterial invasion and the consequent development of caries lesions if the

  1. Scanning thermal lithography of tailored tert-butyl ester protected carboxylic acid functionalized (meth)acrylate polymer platforms.

    Science.gov (United States)

    Duvigneau, Joost; Schönherr, Holger; Vancso, G Julius

    2011-10-01

    In this paper, we report on the development of tailored polymer films for high-resolution atomic force microscopy based scanning thermal lithography (SThL). In particular, full control of surface chemical and topographical structuring was sought. Thin cross-linked films comprising poly(tert-butyl methacrylate) (MA(20)) or poly(tert-butyl acrylate) (A(20)) were prepared via UV initiated free radical polymerization. Thermogravimetric analysis (TGA) and FTIR spectroscopy showed that the heat-induced thermal decomposition of MA(20) by oxidative depolymerization is initially the primary reaction followed by tert-butyl ester thermolysis. By contrast, no significant depolymerization was observed for A(20). For A(20) and MA(20) (at higher temperatures and/or longer reaction times) the thermolysis of the tert-butyl ester liberates isobutylene and yields carboxylic acid groups, which react further intramolecularly to cyclic anhydrides. The values of the apparent activation energies (E(a)) for the thermolysis were calculated to be 125 ± 13 kJ mol(-1) and 116 ± 7 kJ mol(-1) for MA(20) and A(20), respectively. Both MA(20) and A(20) films showed improved thermomechanical stability during SThL compared to non cross-linked films. Carboxylic acid functionalized lines written by SThL in A(20) films had a typically ~10 times smaller width compared to those written in MA(20) films regardless of the tip radius of the heated probe and did not show any evidence for thermochemically or thermomechanically induced modification of film topography. These observations and the E(a) of 45 ± 3 kJ mol(-1) for groove formation in MA(20) estimated from the observed volume loss are attributed to oxidative thermal depolymerization during SThL of MA(20) films, which is considered to be the dominant reaction mechanism for MA(20). The smallest line width values obtained for MA(20) and A(20) films with SThL were 83 ± 7 nm and 21 ± 2 nm, whereas the depth of the lines was below 1 nm, respectively.

  2. Folic acid conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel for site specific delivery of hydrophobic drugs to cancer cells.

    Science.gov (United States)

    Pillai, Jisha Jayadevan; Thulasidasan, Arun Kumar Theralikattu; Anto, Ruby John; Chithralekha, Devika Nandan; Narayanan, Ashwanikumar; Kumar, Gopalakrishnapillai Sankaramangalam Vinod

    2014-07-15

    The hydrogel based system is found to be rarely reported for the delivery of hydrophobic drug due to the incompatibility of hydrophilicity of the polymer network and the hydrophobicity of drug. This problem can be solved by preparing semi-interpenetrating network of cross-linked polymer for tuning the hydrophilicity so as to entrap the hydrophobic drugs. The current study is to develop a folic acid conjugated cross-linked pH sensitive, biocompatible polymeric hydrogel to achieve a site specific drug delivery. For that, we have synthesized a folic acid conjugated PEG cross-linked acrylic polymer (FA-CLAP) hydrogel and investigated its loading and release of curcumin. The formed polymer hydrogel was then conjugated with folic acid for the site specific delivery of curcumin to cancer cells and then further characterized and conducted the cell uptake and cytotoxicity studies on human cervical cancer cell lines (HeLa). In this study, we synthesized folic acid conjugated cross-linked acrylic hydrogel for the delivery of hydrophobic drugs to the cancer site. Poly (ethyleneglycol) (PEG) diacrylate cross-linked acrylic polymer (PAA) was prepared via inverse emulsion polymerization technique and later conjugated it with folic acid (FA-CLAP). Hydrophobic drug curcumin is entrapped into it and investigated the entrapment efficiency. Characterization of synthesized hydogel was done by using Fourier Transform-Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC). Polymerization and folate conjugation was confirmed by FT-IR spectroscopy. The release kinetics of drug from the entrapped form was studied which showed initial burst release followed by sustained release due to swelling and increased cross-linking. In vitro cytotoxicity and cell uptake studies were conducted in human cervical cancer (HeLa) cell lines. Results showed that curcumin entrapped folate conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel showed

  3. Preparation and characterization of nanocomposites of natural rubber with polystyrene and styrene-methacrylic acid copolymer nanoparticles

    Directory of Open Access Journals (Sweden)

    T. Nuruk

    2012-06-01

    Full Text Available Composites of natural rubber (NR/vinyl polymer nanoparticles as polystyrene (PS and poly(styrenemethacrylic acid (P(S-MAA were prepared by heterocoagulation technique. The polymer nanoparticles were prepared by emulsifier-free emulsion polymerizations at 70°C using potassium persulfate as initiator. Under acidic condition where positive charge was present on the NR latex (NRL surface, the nanoparticles having negative charge mainly from sulfate group of initiator were able to adsorb on the NRL surface, the electrostatic interaction being the driving force. The scanning electron micrographs showed that the polymer nanoparticles are homogenously distributed throughout NR matrix as nanoclusters with an average size of about 500 and 200 nm for PS and P(S-MAA, respectively. The mechanical properties of NR/PS and NR/P(S-MAA composite films were compared with the NR host. The nanocomposites, particularly when the polymer nanoparticles are uniformly dispersed, possess significantly enhanced mechanical properties strongly depending on the morphology of the nanocomposites.

  4. Formation of High-Capacity Protein-Adsorbing Membranes Through Simple Adsorption of Poly(acrylic acid)-Containing Films at low pH

    OpenAIRE

    Bhattacharjee, Somnath; Dong, Jinlan; Ma, Yiding; Hovde, Stacy; Geiger, James H.; Baker, Gregory L.; Bruening, Merlin L

    2012-01-01

    Layer-by-layer polyelectrolyte adsorption is a simple, convenient method for introducing ion-exchange sites in porous membranes. This study demonstrates that adsorption of poly(acrylic acid) (PAA)-containing films at pH 3 rather than pH 5 increases the protein-binding capacity of such polyelectrolyte-modified membranes 3- to 6-fold. The low adsorption pH generates a high density of –COOH groups that function as either ion-exchange sites or points for covalent immobilization of metal-ion compl...

  5. Effect Of Sodium Hypochlorite And Peracetic Acid On The Surface Roughness Of Acrylic Resin Polymerized By Heated Water For Short And Long Cycles.

    OpenAIRE

    Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

    2015-01-01

    Objective: To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). Materials and Methods: The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, di...

  6. Studies on the Electrical Properties of Graphene Oxide-Reinforced Poly (4-Styrene Sulfonic Acid) and Polyvinyl Alcohol Blend Composites

    Science.gov (United States)

    Deshmukh, Kalim; Sankaran, Sowmya; Basheer Ahamed, M.; Khadheer Pasha, S. K.; Sadasivuni, Kishor Kumar; Ponnamma, Deepalekshmi; Al-Ali Almaadeed, Mariam; Chidambaram, K.

    In the present study, graphene oxide (GO)-reinforced poly (4-styrenesulfonic acid) (PSSA)/polyvinyl alcohol (PVA) blend composite films were prepared using colloidal blending technique at various concentrations of GO (0-3wt.%). The morphological investigations of the prepared composites were carried out using polarized optical microscopy and scanning electron microscopy. The electrical properties of composites were evaluated using an impedance analyzer in the frequency range 50Hz to 20MHz and temperature in the range 40-150∘C. Morphological studies infer that GO was homogeneously dispersed in the PSSA/PVA blend matrix. Investigations of electrical property indicate that the incorporation of GO into PSSA/PVA blend matrix resulted in the enhancement of the impedance (Z) and the quality factor (Q-factor) values. A maximum impedance of about 4.32×106Ω was observed at 50Hz and 90∘C for PSSA/PVA/GO composites with 3wt.% GO loading. The Q-factor also increased from 8.37 for PSSA/PVA blend to 59.8 for PSSA/PVA/GO composites with 3wt.% GO loading. These results indicate that PSSA/PVA/GO composites can be used for high-Q capacitor applications.

  7. Surface modification of aramid fiber by plasma induced vapor phase graft polymerization of acrylic acid. I. Influence of plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Du, M. [College of Textiles and Clothing, Yancheng Institute of Industry Technology, Jiangsu 224000 (China); Lv, J.C.; Zhou, Q.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Liu, G.L.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2015-09-15

    Highlights: • Aramid fiber surface was modified by PIVPGP of AA to improve wettability, adhesion. • Surface modification effect by PIVPGP of AA increased and then decreased with time. • Surface modification effect increased and then stayed unaltered with output power. • Ar plasma was the most effective in PIVPGP of AA on aramid fiber surface. • In studied range, optimum technology of PIVPGP of AA: Ar plasma, 15 min, 300 W. - Abstract: Plasma induced vapor phase graft polymerization (PIVPGP) method was applied to modify aramid fiber surface. In this study, aramid fibers were pretreated under various plasma conditions such as different treatment times, output powers and working gases to see how these plasma processing parameters influenced the PIVPGP of acrylic acid (AA) on aramid fiber surface and its surface structure and properties. The analysis results of atomic force microscope (AFM) and X-ray photoelectron spectroscope (XPS) showed the increase of surface roughness and the introduction of O=C−OH, which confirmed that the PIVPGP of AA on aramid fiber surface was achieved. The contact angle and interfacial shear strength (IFSS) of the aramid fibers modified by PIVPGP of AA prominently decreased and increased, respectively, indicating the obvious improvements of surface wettability and adhesion between aramid fiber and matrix. The surface modification effects of aramid fiber by PIVPGP of AA firstly increased and then after 15 min slightly decreased with the increasing plasma treatment time, and but firstly increased and then after 300 W nearly remained unchanged with the increasing output power, respectively. Among different working gases, Ar plasma occupied first place, O{sub 2} plasma and N{sub 2} plasma came second and third in the aspect of PIVPGP of AA on aramid fiber surface, respectively. It could be concluded that the PIVPGP of AA on aramid fiber surface could effectively improve surface wettability and adhesion. Plasma conditions had signally

  8. Curcumin delivery from poly(acrylic acid-co-methyl methacrylate) hollow microparticles prevents dopamine-induced toxicity in rat brain synaptosomes.

    Science.gov (United States)

    Yoncheva, Krassimira; Kondeva-Burdina, Magdalena; Tzankova, Virginia; Petrov, Petar; Laouani, Mohamed; Halacheva, Silvia S

    2015-01-01

    The potential of poly(methyl methacrylate-co-acrylic acid) (PMMA-AA) copolymers to form hollow particles and their further formulation as curcumin delivery system have been explored. The particles were functionalized by crosslinking the acrylic acid groups via bis-amide formation with either cystamine (CYS) or 3,3'-dithiodipropionic acid dihydrazide (DTP) which simultaneously incorporated reversibility due to the presence of disulfide bonds within the crosslinker. Optical micrographs showed the formation of spherical hollow microparticles with a size ranging from 1 to 7 μm. Curcumin was loaded by incubation of its ethanol solution with aqueous dispersions of the cross-linked particles and subsequent evaporation of the ethanol. Higher loading was observed in the microparticles with higher content of hydrophobic PMMA units indicating its influence upon the loading of hydrophobic molecules such as curcumin. The in vitro release studies in a phosphate buffer showed no initial burst effect and sustained release of curcumin that correlated with the swelling of the particles under these conditions. The capacity of encapsulated and free curcumin to protect rat brain synaptosomes against dopamine-induced neurotoxicity was examined. The encapsulated curcumin showed greater protective effects in rat brain synaptosomes as measured by synaptosomal viability and increased intracellular levels of glutathione. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Polystyrene cups and containers: styrene migration.

    Science.gov (United States)

    Tawfik, M S; Huyghebaert, A

    1998-07-01

    The level of styrene migration from polystyrene cups was monitored in different food systems including: water, milk (0.5, 1.55 and 3.6% fat), cold beverages (apple juice, orange juice, carbonated water, cola, beer and chocolate drink), hot beverages (tea, coffee, chocolate and soup (0.0, 0.5, 1, 2, and 3.6% fat), take away foods (yogurt, jelly, pudding and ice-cream), as well as aqueous food simulants (3% acetic acid, 15, 50, and 100% ethanol) and olive oil. Styrene migration was found to be strongly dependent upon the fat content and storage temperature. Drinking water gave migration values considerably lower than all of the fatty foods. Ethanol at 15% showed a migration level equivalent to milk or soup containing 3.6% fat. Maximum observed migration for cold or hot beverages and take-away foods was 0.025% of the total styrene in the cup. Food simulants were responsible for higher migration (0.37% in 100% ethanol). A total of 60 food samples (yogurt, rice with milk, fromage, biogardes, and cheese) packed in polystyrene containers were collected from retail markets in Belgium, Germany, and the Netherlands. The level of styrene detected in the foods was always fat dependent.

  10. Removal of Copper Ions from Aqueous Solution with a Weak Cation Exchanger by Radiation-Induction Grafting Acrylic Acid onto Polypropylene Fiber

    Directory of Open Access Journals (Sweden)

    Zhongxin Ji

    2011-01-01

    Full Text Available A carboxylic acid chelating fiber with high adsorption capacity for copper ions was prepared by grafting acrylic acid onto polypropylene fiber using pre-irradiation method. Effects of reaction conditions such as pH, initial copper concentration and adsorption time were discussed. The results showed that carboxylic acid chelating fiber is effective for the removal of copper ions in the range of pH=4.0-7.0. The chelating fiber also showed much higher capacities for copper, the equilibrium adsorption amount could be 24.35 mg/g for copper adsorption This chelating fibers exhibited good potential application in removal of copper ions in aqueous solution.

  11. Temperature-, pH- and CO2-Sensitive Poly(N-isopropylacryl amide-co-acrylic acid Copolymers with High Glass Transition Temperatures

    Directory of Open Access Journals (Sweden)

    Yeong-Tarng Shieh

    2016-12-01

    Full Text Available A series of poly(N-isopropylacrylamide-co-acrylic acid (PNIPAAm-co-PAA random copolymers were synthesized through free radical copolymerization in MeOH. The incorporation of the acrylic acid units into PNIPAAm tended to enhance the glass transition temperature (Tg, due to strong intermolecular hydrogen bonding between the amide groups of PNIPAAm and the carboxyl groups of PAA, as observed using 1H nuclear magnetic resonance (NMR and Fourier transform infrared (FTIR spectroscopic analyses. The lower critical solution temperature (LCST increased upon increasing the pH of the aqueous solution containing PNIPAAm-co-PAA because the COOH groups of the PAA segment dissociated into COO− groups, enhancing the solubility of the copolymer. In addition, high-pressure differential scanning calorimetry revealed that the LCSTs of all the aqueous solutions of the copolymers decreased upon increasing the pressure of CO2, suggesting that CO2 molecules had displaced H2O molecules around the polar CONH and COOH groups in PNIPAAm-co-PAA, thereby promoting the hydrophobicity of the copolymers in the aqueous solution. In addition, the values of Tg of a film sample increased upon treatment with supercritical CO2, implying that intermolecular interactions in the copolymer had been enhanced after such treatment.

  12. Magnetic Solid-Phase Extraction Based on β-Cyclodextrins/Acrylic Acid Modified Magnetic Gelatin for Determination of Moxidectin in Milk Samples

    Directory of Open Access Journals (Sweden)

    Yinzhu Shang

    2016-01-01

    Full Text Available β-Cyclodextrins/acrylic acid modified magnetic gelatin was prepared and then employed as the magnetic solid-phase extraction (MSPE sorbent for extraction of moxidectin in milk samples. Due to the rigidity of hydrophobic cavity of β-cyclodextrins and carboxyl groups of acrylic acid, magnetic composites are prepared to form a complex with target molecules through various kinds of chemical reactions and then showed excellent extraction performance. This method exhibits the advantages of simplicity of implementation, short extraction time (5 min, low solvent consumption, and high extraction efficiency. A rapid, simple, and effective method for the analysis of moxidectin in milk samples was established by MSPE coupled with liquid chromatography-fluorescence detection. The limit of detection was 0.1 ng·mL−1 and the recoveries from milk samples were in the range of 93.8%–112.5%. The relative standard deviation was not higher than 6.4%. In conclusion, magnetic solid-phase extraction is a simple and robust preconcentration technique that can be coupled to other analytical methods for the quantitative determination of target molecules in complex samples.

  13. Mucoadhesive drug carrier based on interpolymer complex of poly(vinyl pyrrolidone) and poly(acrylic acid) prepared by template polymerization.

    Science.gov (United States)

    Chun, Myung Kwan; Cho, Chong Su; Choi, Hoo Kyun

    2002-06-17

    To develop a new mucoadhesive drug carrier, poly(vinyl pyrrolidone) (PVP)/poly(acrylic acid) (PAA) interpolymer complexes were prepared by the template polymerization of acrylic acid using PVP as a template polymer. Fourier transform infrared results showed that the interpolymer complexes were formed by hydrogen bonds between the carboxyl groups of PAA and the carbonyl groups of PVP. The adhesive forces of the PVP/PAA interpolymer complexes were higher than that of commercial Carbopol 971. Moreover, the adhesive force and the release rate can be controlled by changing the mole ratios of PVP and PAA. The release rates of ketoprofen from the PVP/PAA interpolymer complexes showed pH-dependency, and were slower at lower pH. The release rate of ketoprofen from the complex seemed to be mainly controlled by the dissolution rate of the complex above a pK(a) of PAA (4.75) and by the diffusion rate below the pK(a). The prepared complex appears to be an adequate carrier for the mucoadhesive drug delivery system.

  14. Synthesis of lithium iron phosphate/carbon microspheres by using polyacrylic acid coated iron phosphate nanoparticles derived from iron(III) acrylate.

    Science.gov (United States)

    Xu, Dongwei; He, Yan-Bing; Chu, Xiaodong; Ding, Zhaojun; Li, Baohua; He, Jianfu; Du, Hongda; Qin, Xianying; Kang, Feiyu

    2015-03-01

    Lithium iron phosphate/carbon (LiFePO4 /C) microspheres with high rate and cycling performance are synthesized from iron phosphate/polyacrylic acid (FePO4 /PAA) nanoparticles. Iron(III) acrylate is used as a precursor for both the iron and carbon sources. FePO4 nanoparticles are first produced by a coprecipitation reaction. The byproduct, acrylic acid ions, is polymerized in situ to form a uniform PAA layer on the surface of the FePO4 nanoparticles. The as-prepared LiFePO4 /C microspheres are composed of primary nanoparticles with sizes of 40-50 nm. The nanoparticles are fully coated with a thin, uniform carbon layer derived from the decomposition of the PAA layer. The uniform carbon-coating layer cooperates with interstitial and boundary carbon derived from sucrose successfully to construct an excellent interconnecting conductive network in the microspheres. As a result of the unique structure, the as-prepared LiFePO4 /C microspheres display both high electronic and ionic conductivities, which contribute to their high rate performance (162.9 mAh g(-1) at 0.1C and 126.1 mAh g(-1) at 5C) and excellent cycling stability (97.1% of capacity retention after 500 cycles at 5C/5C). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Accurate quantification of mercapturic acids of styrene (PHEMAs) in human urine with direct sample injection using automated column-switching high-performance liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Reska, M; Ochsmann, E; Kraus, T; Schettgen, T

    2010-08-01

    Styrene is one of the most important industrial chemicals, with an enormously high production volume worldwide. The urinary mercapturic acids of its metabolite styrene-7,8-oxide, namely N-acetyl-S-(2-hydroxy-1-phenylethyl)-L-cysteine (PHEMA 1) and N-acetyl-S-(2-hydroxy-2-phenylethyl)-L-cysteine (PHEMA 2), are specific biomarkers for the determination of individual internal exposure to this highly reactive intermediate of styrene. We have developed and validated a fast, specific and very sensitive method for the accurate determination of the sum of phenylhydroxyethyl mercapturic acids (PHEMAs) in human urine with an automated multidimensional liquid chromatography-tandem mass spectrometry method using (13)C(6)-labelled PHEMAs as internal standards. Analytes were stripped from the urinary matrix by online extraction on a restricted access material, transferred to the analytical column and subsequently determined by tandem mass spectrometry. The limit of quantification (LOQ) for the sum of PHEMAs was 0.3 microg/L urine and allowed us to quantify the background exposure of the (smoking) general population. Precision within series and between series ranged from 1.5 to 6.8% at three concentrations ranging from 3 to 30 microg/L urine; the mean accuracy was between 104 and 110%. We applied the method to spot urine samples from 40 subjects of the general population with no known occupational exposure to styrene. The median levels (range) for the sum of PHEMAs in urine of non-smokers (n = 22) were less than 0.3 microg/L (less than 0.3 to 1.1 microg/L), whereas in urine of smokers (n = 18), the median levels were 0.46 microg/L (less than 0.3 to 2.8 microg/L). Smokers showed a significantly higher excretion of the sum of PHEMAs (p = 0.02). Owing to its automation and high sensitivity, our method is well suited for application in occupational or environmental studies.

  16. Preliminary study of styrene grafting on polyethylene films

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Gilberto de O.; Geraldes, Adriana N.; Zen, Heloisa A.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: gibamaclarenn@hotmail.com

    2007-07-01

    Grafting of styrene on polyethylene was carried out as a preliminary study. The experiments covered a range from 5 to 20 kGy and intended to evaluate the absorbed dose that led to the best degree of grafting (DOG) under industrial dose rate. PE films 0,065 mm thick were exposed several times to radiation at room temperature and nitrogen atmosphere. The films were immersed in the solution content styrene/solvent then irradiated (5 to 20 kGy) dose. As an exploratory experiment, styrene grafting was gravimetrically evaluated and characterized by infrared spectroscopy (FTIR).The degree of grafting (DOG) was calculated. Concentrations of methanol/ Styrene at the rate of 80:20 were favorable at low dose of 10 kGy. In presence of acid, best result was achieved at 15 kGy in the range of 5 to 20 kGy. (author)

  17. Chromosomal aberrations in lymphocytes of workers exposed to low levels of styrene

    Energy Technology Data Exchange (ETDEWEB)

    Nordenson, I.; Beckman, L.

    1984-01-01

    Chromosomal aberrations were studied in lymphocytes of 15 workers exposed to styrene and 13 controls. The average styrene concentration in the work room air was 24 ppm, and the levels of urinary mandelic acid were below 2 mmol/l. No significant increase in the rates of gaps and breaks was found. However, the rate of micronuclei was significantly increased, which indicates that the mitotic spindle mechanism may be more sensitive to styrene and its metabolites than DNA.

  18. Denitrification with acrylamide by pure culture of bacteria isolated from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.

    Science.gov (United States)

    Wang, C C; Lee, C M

    2001-08-01

    Acrylamide is widely used in industrial applications as cement binder and solidification agent. Due to its carcinogenicity and toxicity, discharge of acrylamide to the natural water and soil systems may lead to an adverse environmental impact on water quality and thus endanger public health and welfare. This study attempts to isolate and identify the denitrifying bacteria, which utilize acrylamide as the substrate from the acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system. The performance of the denitrifying bacteria for treating different initial acrylamide concentrations was also investigated under aerobic and anaerobic conditions. The test results indicated that the Pseudomonas stutzeri could remove acrylamide at concentrations below 440 mg/l under aerobic conditions. The acrylic acid and ammonia intermediates were used as carbon and nitrogen sources, respectively. However, P. stutzeri did not show the capability of metabolizing acrylonitrile under aerobic conditions. Furthermore, the P. stutzeri could utilize both acrylamide and acrylic acid in the presence of nitrate (denitrification) and acrylamide could be removed completely from the wastewater.

  19. Enhanced Swelling and Responsive Properties of Pineapple Peel Carboxymethyl Cellulose-g-poly(acrylic acid-co-acrylamide) Superabsorbent Hydrogel by the Introduction of Carclazyte.

    Science.gov (United States)

    Dai, Hongjie; Huang, Huihua

    2017-01-25

    The superabsorbent hydrogels were synthesized by grafting acrylic acid and acrylamide onto pineapple peel carboxymethyl cellulose and effect of carclazyte introduction was compared. The structure and morphology of the superabsorbents were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. Swelling behaviors of the superabsorbents were investigated in distilled water, 0.9% NaCl solution, various salt and pH solutions, as well as surfactant solutions and simulated physiological fluids. The swelling dynamic mechanism of the superabsorbents was explained well by Fickian diffusion and Schott's pseudo-second-order models. The introduction of carclazyte effectively improved the swelling capacity of the superabsorbents in various solutions as well as its salt- and pH-sensitivity. The prepared superabsorbents also exhibited excellent sensitivities to various surfactant solutions and simulated physiological fluids, showing potential applications in the biomaterials field.

  20. Influence of the degree of neutralization of acrylic acid and cross-linking agent on optical properties and swelling of sodium polyacrylate

    Science.gov (United States)

    Gredyukhina, I. V.; Plotnikova, L. V.; Balbekin, N. S.; Kulya, M. S.; Petrov, N. V.; Nechiporenko, A. P.; Uspenskaya, M. V.

    2017-06-01

    Optical characteristics of polymerization products under variable degrees of neutralization of acrylic acid (AA) and cross-linking agent and at a fixed content of redox components have been studied by IR spectroscopy of frustrated total internal reflection and THz spectroscopy. The results of the analysis show that absorption of IR radiation and dispersion of THz radiation for the samples under study depend on the degree of AA neutralization, which predetermines the mechanism of structure formation of hydrogels, refractive index, and degree of their limited swelling. It is found that the dependences of the refractive index of dry compact hydrogels and the degree of limited swelling of ground polymer samples on the content of neutralizing agent in solutions of the reaction systems have a symbatic character.

  1. Preparation and characterization of electrically conductive composites of poly(vinyl alcohol–g–poly(acrylic acid hydrogels impregnated with polyaniline (PANI

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available Novel electrically conducting composite materials consisting of poly(aniline (PANI nanoparticles dispersed in a poly(vinyl alcohol (PVA-g-poly(acrylic acid (PAA hydrogels were prepared within the polymer matrix by in situ polymerization of aniline. The conversion yield of aniline into PANI particles was determined gravimetrically while structural confirmation of the synthesized polymer was sought by Fourier Transform Infrared (FTIR, UV-visible analysis and X-ray diffraction (XRD technique. Morphology and dimension of PANI particles embedded into the colored optically semi-transparent hydrogels were evaluated by Scanning Electron Microscopy (SEM analysis. Electrical conductivity of composite hydrogels of different composition was determined by LCR meter while electroactive behavior of composite hydrogels swollen in electrolyte solution was investigated by Effective Bend Angle (EBA measurements.

  2. Preparation of porous carboxymethyl chitosan grafted poly (acrylic acid) superabsorbent by solvent precipitation and its application as a hemostatic wound dressing.

    Science.gov (United States)

    Chen, Yu; Zhang, Yong; Wang, Fengju; Meng, Weiwei; Yang, Xinlin; Li, Peng; Jiang, Jianxin; Tan, Huimin; Zheng, Yongfa

    2016-06-01

    The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Structural changes of polyacids initiated by their neutralization with various alkali metal hydroxides. Diffusion studies in poly(acrylic acid)s.

    Science.gov (United States)

    Masiak, Michal; Hyk, Wojciech; Stojek, Zbigniew; Ciszkowska, Malgorzata

    2007-09-27

    The changes in the three-dimensional structure of the poly(acrylic acid), PAA, induced by incorporation of various alkali-metal counterions have been evaluated by studying diffusion of an uncharged probe (1,1'-ferrocenedimethanol) in the polymeric media. The studies are supported by the measurements of conductivity and viscosity of the polymeric media. Solutions of linear PAA of four different sizes (molecular weights: 450,000, 750,000, 1,250,000, 4,000,000) were neutralized with hydroxides of alkali metals of group 1 of the periodic table (Li, Na, K, Rb, Cs) to the desired neutralization degree. The transport properties of the obtained polyacrylates were monitored by measuring the changes in the probe diffusion coefficient during the titration of the polyacids. The probe diffusivity was determined from the steady-state current of the probe voltammetric oxidation at disk microelectrodes. Diffusivity of the probe increases with the increase in the degree of neutralization and with the increase in viscosity. It reaches the maximum value at about 60-80% of the polyacid neutralization. The way the probe diffusion coefficients change is similar in all polyacid solutions and gels. The increase in the size of a metal cation causes, in general, an enhancement in the transport of probe molecules. The biggest differences in the probe diffusivities are between lithium and cesium polyacrylates. The differences between the results obtained for cesium and rubidium are not statistically significant due to lack of good precision of the voltammetric measurements. The measurements of the electric conductivity of polyacrylates and the theoretical predictions supplemented the picture of electrostatic interactions between the polyanionic chains and the metal cations of increasing size. In all instances of the PAAs, the viscosity of the solutions rapidly increases in the 0-60% range of neutralization and then becomes constant in the 60-100% region. With the exception of the shortest

  4. Surface characterization of poly(vinyl chloride) urinary catheters functionalized with acrylic acid and poly(ethylene glycol) methacrylate using gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Islas, Luisa [Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F. 04510 (Mexico); Ruiz, Juan-Carlos [División de Ciencias Básicas e Ingeniería, Depto. de Ingeniería de Procesos e Hidráulica, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, 09340 México D.F. (Mexico); Muñoz-Muñoz, Franklin [Facultad de Ingeniería, Arquitectura y Diseño, Universidad Autónoma de Baja California, Carretera Transpeninsular Ensenada-Tijuana 3917, Ensenada, B.C. C.P 22860 (Mexico); Isoshima, Takashi [Nano Medical Engineering Laboratory, RIKEN, 2-1Hirosawa, Wako, Saitama 351-0198 (Japan); Burillo, Guillermina, E-mail: burillo@nucleares.unam.mx [Departamento de Química de Radiaciones y Radioquímica, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F. 04510 (Mexico)

    2016-10-30

    Highlights: • Polymer grafting using gamma-radiation allowed for acrylic acid and poly(ethylene glycol) methacrylate to graft on the inner and outer surface of poly(vinyl chloride) urinary catheters. • HR-XPS revealed the different compositional percentages of the compounds present on the surface of the catheter. • Catheters that were grafted with PEGMA had the roughest surface as observed using scanning electron microscopy (SEM) and confocal laser microscopy (CLM). - Abstract: Poly(vinyl chloride) (PVC) urinary catheters were modified with either a single or binary graft of acrylic acid (AAc) and/or poly(ethylene glycol) methacrylate (PEGMA) using gamma-radiation from {sup 60}Co to obtain PVC-g-AAc, PVC-g-PEGMA, [PVC-g-AAc]-g-PEGMA, and [PVC-g-PEGMA]-g-AAc copolymers. The outer and inner surfaces of the modified catheters were characterized using scanning electron microscopy (SEM), confocal laser microscopy (CLM) and X-ray photoelectron spectroscopy (XPS). The XPS analyses, by examining the correlation between the variation of the C{sub 1s} and O{sub 1s} content at the catheter’s surface, revealed that the catheter’s surfaces were successfully grafted with the chosen compounds, with those that were binary grafted showing a slightly more covered surface as was evidenced by the disappearance of PVC’s Cl peak. The SEM and CLM analyses revealed that catheters that had been grafted with PEGMA had a rougher outer surface as compared to those that had only been grafted with AAc. In addition, these imaging techniques showed that the inner surface of the singly grafted catheters, whether they had been grafted with AAc or PEGMA, retained some smoothness at the analyzed grafting percentages, while the binary grafted catheters showed many protuberances and greater roughness on both outer and inner surfaces.

  5. A new style for synthesis of thermo-responsive Fe3O4/poly (methylmethacrylate-b-N-isopropylacrylamide-b-acrylic acid) magnetic composite nanosphere and theranostic applications.

    Science.gov (United States)

    Ghamkhari, Aliyeh; Massoumi, Bakhshali; Salehi, Roya

    2017-12-01

    In this work, a novel thermo-responsive Fe3O4/poly(methylmethacrylate-b-N-isopropylacrylamide-b-acrylic acid) magnetic composite nanosphere was synthesized for anticancer drug delivery applications. For this propose, the poly(methylmethacrylate-b-N-isopropylacrylamide-b-acrylic acid) [poly (MMA-b-NIPAAm-b-AAc)] was synthesized via reversible addition-fragmentation transfer method. The physic-chemical characterization of the Fe3O4/poly(MMA-b-NIPAAm-b-AAc) magnetic composite nanosphere was investigated by FTIR, HNMR spectroscopies and GPC, FESEM, XRD, VSM and DLS. The thermo-sensitivity of the Fe3O4/P(MMA-b-NIPAAm-b-AAc) magnetic composite nanosphere was confirmed via DLS at 40 °C. DOX encapsulation efficiency was calculated to be 98.2%. The effect of temperature and pH on release behaviors of stimuli responsive DOX-loaded Fe3O4/P(MMA-b-NIPAAm-b-AAc)] magnetic composite nanosphere were investigated. The release rate at pH 7.4, 5.4 and 4 (T = 37 °C) was reached about 24.4, 42.4 and 57.5 wt%, after 4-5 day. The release rate improved at tumor simulated environment (t:40 °C and pH ≤ 5.4). The cytotoxic effects of the magnetic composite nanosphere were appraised by MTT assay and the results indicated that novel developed smart nanocomposite here was nontoxic to MCF-7 cells and can be applied as anti-cancer drug delivery system. Also, the results of the Cellular uptake of MCF7 cells treated with rhodamine labeled DOX-loaded nanocarrier for 2 h have indicated that DOX can be applied as cytotoxic agent and targeting ligand.

  6. Photocurable bioactive bone cement based on hydroxyethyl methacrylate-poly(acrylic/maleic) acid resin and mesoporous sol gel-derived bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Hesaraki, S., E-mail: S-hesaraki@merc.ac.ir

    2016-06-01

    This paper reports on strong and bioactive bone cement based on ternary bioactive SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass particles and a photocurable resin comprising hydroxyethyl methacrylate (HEMA) and poly(acrylic/maleic) acid. The as-cured composite represented a compressive strength of about 95 MPa but it weakened during soaking in simulated body fluid, SBF, qua its compressive strength reached to about 20 MPa after immersing for 30 days. Biodegradability of the composite was confirmed by reducing its initial weight (~ 32%) as well as decreasing the molecular weight of early cured resin during the soaking procedure. The composite exhibited in vitro calcium phosphate precipitation in the form of nanosized carbonated hydroxyapatite, which indicates its bone bonding ability. Proliferation of calvarium-derived newborn rat osteoblasts seeded on top of the composite was observed during incubation at 37 °C, meanwhile, an adequate cell supporting ability was found. Consequently, it seems that the produced composite is an appropriate alternative for bone defect injuries, because of its good cell responses, high compressive strength and ongoing biodegradability, though more in vivo experiments are essential to confirm this assumption. - Highlights: • Light cure cement based on SiO{sub 2}-CaO-P{sub 2}O{sub 5} glass and polymer-like matrix was formed. • The matrix includes poly(acrylic/maleic acid) and poly(hydroxyethyl methacrylate). • The cement is as strong as polymethylmethacrylate bone cement. • The cement exhibits apatite formation ability in simulated body fluid. • The cement is biodegradable and supports proliferation of osteoblastic cells.

  7. Properties of Eco-friendly Acrylic Resin/Clay Nanocomposites Prepared by Non-aqueous Dispersion (NAD) Polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeongho; Lee, Minho; Jeon, Hyeon Yeol; Min, Byong Hun; Kim, Jeong Ho [Univ. of Suwon, Hwaseong (Korea, Republic of); Lee, Young Chul [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2016-02-15

    Eco-friendly acrylic resin/clay nanocomposites containing pristine montmorillonite (PM) or modified clays (30B and 25A) were prepared from acrylic and styrenic monomers using non-aqueous dispersion (NAD) polymerization. Effect of nanoclays on physical properties of polymerization product and resulting nanocomposites was investigated. In view of NAD particle stability, addition of nanoclay at the beginning of polymerization is proved to be good. Results of gel fraction, acid value and viscosity of the NAD product showed that nanocomposites containing clay 25A showed better physical properties than the ones with other clays. GPC results exhibit the increase in molecular weight and decrease in polydispersity index for the 25A nanocomposite. Increase in layer distance confirmed from XRD analysis showed good dispersion of 25A in the nanocomposite. Thermal and dynamic mechanical analysis showed that highest glass transition temperature and storage modulus for 25A nanocomposites. These results indicate that 25A nanoclay gives the best properties in the process of non-aqueous dispersion polymerization of acrylic resin/nanoclay nanocomposites.

  8. Organocopper reactions with allylic acrylates. The preparation of {gamma},{delta}-unsaturated acids and the subsequent transformation to {gamma}-lactones

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, M.; Nilsson, M.; Olsson, T. [Chalmers Univ. of Technology, Goeteborg (Sweden)

    1995-12-31

    The conjugate addition of organocopper reagents to {alpha},{beta}-unsaturated ketones and esters is a commonly used method for carbon-carbon bond formation. When this is applied on allylic enoates, the primary ester enolates/silyl ketene acetals from the addition undergo Claisen rearrangement at room temperature to afford diastereomeric mixtures of {gamma},{delta}-unsaturated acids after hydrolytic work-up. The E/Z ratio for the primary ester enolates/silyl ketene acetals controls the erythro:threo ratio for the {gamma},{delta}-unsaturated acids. The present work is an investigation of different organocopper reagents (e.g. RCu(LiI)-TMSI) in reactions with crotyl and cinnamyl acrylate. The diastereomeric ratio is strongly influenced by the organocopper reagent (RCu(LiI) vs R{sub 2}CuLi(LiI)) as well as the additive (TMSCl vs TMSI). Subsequent iodolactonization of the {gamma},{delta}-unsaturated acids followed by reduction give trisubstituted {gamma}-lactones in good overall yields.

  9. Effects of the peracetic acid and sodium hypochlorite on the colour stability and surface roughness of the denture base acrylic resins polymerised by microwave and water bath methods.

    Science.gov (United States)

    Fernandes, Flavio H C N; Orsi, Iara A; Villabona, Camilo A

    2013-03-01

    This study evaluated the surface roughness (Ra) and color stability of acrylic resin colors (Lucitone 550, QC-20 and Vipi-Wave) used for fabricating bases for complete, removable dentures, overdentures and prosthetic protocol after immersion in chemical disinfectants (1% sodium hypochlorite and 2% peracetic acid) for 30 and 60 minutes. Sixty specimens were made of each commercial brand of resin composite, and divided into 2 groups according to the chemical disinfectants. Specimens had undergone the finishing and polishing procedures, the initial color and roughness measurements were taken (t=0), and after this, ten test specimens of each commercial brand of resin composite were immersed in sodium hypochlorite and ten in peracetic acid, for 30 and 60 minutes, with measurements being taken after each immersion period. These data were submitted to statistical analysis. There was evidence of an increase in Ra after 30 minutes immersion in the disinfectants in all the resins, with QC-20 presenting the highest Ra values, and Vipi-Wave the lowest. After 60 minutes immersion in the disinfectants all the resins presented statistically significant color alteration. Disinfection with 1% sodium hypochlorite and peracetic acid altered the properties of roughness and color of the resins. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  10. Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles.

    Science.gov (United States)

    Sczepanski, Felipe; Sczepanski, Claudia Roberta Brunnquell; Berger, Sandrine Bittencourt; Consani, Rafael Leonardo Xediek; Gonini-Júnior, Alcides; Guiraldo, Ricardo Danil

    2014-10-01

    To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

  11. Fibronectin fixation on poly(ethyl acrylate)-based copolymers.

    Science.gov (United States)

    Briz, N; Antolinos-Turpin, C M; Alió, J; Garagorri, N; Ribelles, J L Gómez; Gómez-Tejedor, J A

    2013-08-01

    The aim of this paper is to quantify the adhered fibronectin (FN; by adsorption and/or grafting) and the exposure of its cell adhesive motifs (RGD and FNIII7-10) on poly(ethyl acrylate) (PEA) copolymers whose chemical composition has been designed to increase wettability and to introduce acid functional groups. FN was adsorbed to PEA, poly(ethyl acrylate-co-hydroxyethyl acrylate), poly(ethyl acrylate-co-acrylic acid), and poly(ethyl acrylate-co-methacrylic acid) copolymers, and covalently cross-linked to poly(ethyl acrylate-co-acrylic acid) and poly(ethyl acrylate-co-methacrylic acid) copolymers. Amount of adhered FN and exhibition of RGD and FNIII7- 10 fragments involved in cell adhesion were quantified with enzyme-linked immunosorbent assay tests. Even copolymers with a lower content of the hydrophilic component showed a decrease in water contact angle. In addition, FN was successfully fixed on all surfaces, especially on the hydrophobic surfaces. However, it was demonstrated that exposure of its cell adhesion sequences, which is the key factor in cell adhesion and proliferation, was higher for hydrophilic surfaces. Copyright © 2013 Wiley Periodicals, Inc.

  12. Human exposure to styrene. IV. Industrial hygiene investigations and biological monitoring in the polyester industry

    Energy Technology Data Exchange (ETDEWEB)

    Guillemin, M.P.; Bauer, D.; Martin, B.; Marazzi, A.

    1982-01-01

    An industrial hygiene study of 10 glassfiber reinforced polyester plants (including 90 workers) was undertaken to investigate the styrene exposure in this industry and to estimate biological limit values (BLV's) for the urinary metabolites of styrene: mandelic (MA) and phenylglyoxylic acids (PGA). Time weighted average (TWA) styrene exposures were found ranging from 2 to 200 ppm. The urinary elimination of metabolites correlated well with exposure and the BLV's corresponding to an 8-h exposure at 100 ppm were consistent with earlier laboratory findings (end-of-shift sample: MA 1640, PGA 510, MA + PGA 2150; next-morning sample: MA 330, PGA 330, MA + PGA 660 mg/g creat.). Total metabolites (MA + PGA) in the next-morning sample or mandelic acid in the end-of-shift sample are recommended for routine monitoring of exposure to styrene. The study revealed the need for further research on how to reduce styrene exposure in this industry.

  13. No acute behavioral effects of exposure to styrene: a safe level of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Edling, C.; Ekberg, K.

    1985-05-01

    To determine whether exposure to low levels of styrene (below 110 mg/m3) causes acute behavioral effects and symptoms that may be related to concentrations of styrene in air or urinary mandelic acid or both, 12 men occupationally exposed to styrene were studied and compared with a reference group of 10 unexposed men. Simple reaction time was measured before and after work and information about symptoms was obtained by questionnaire. Active and passive sampling of airborne styrene was carried out and urinary mandelic acid concentrations were measured. Although the size of the study groups is small, the results indicate that exposure to styrene below 110 mg/m3 does not cause any acute adverse effects on the central nervous system.

  14. A study of the swelling and model protein release behaviours of radiation-formed poly(N-vinyl 2-pyrrolidone-co-acrylic acid) hydrogels

    Science.gov (United States)

    Wang, David; Hill, David J. T.; Rasoul, Firas; Whittaker, Andrew K.

    2011-02-01

    Hydrogels were prepared from poly(acrylic acid-co-N-vinyl pyrrolidone), poly(AA-co-VP) and mixtures of poly(AA-co-VP) and poly(ethylene oxide), PEO, by gamma radiolysis of aqueous solutions of the AA and VP monomers containing ethylene glycol dimethacrylate, EGDMA, as crosslinker and PEO. The AA/VP composition range of the poly(AA-co-VP) was XAA 0.7-0.9. The swelling behaviours of the hydrogels from the dry state were investigated in water (pH 6.5) and 50 mM 4-(2-hydroxyethyl)piperazine-1-ethylsulfonic acid buffer, HEPES buffer, at pH 7.4 and 295 K. The effects of poly(AA-co-VP) composition, crosslinker mole fraction and the presence of PEO on the equilibrium swelling ratio for the gels was examined. The kinetics of the release of a model protein, horseradish peroxidase, HRP, from the hydrogels in water were also studied at 295 K.

  15. Physically cross-linked polymer binder based on poly(acrylic acid) and ion-conducting poly(ethylene glycol-co-benzimidazole) for silicon anodes

    Science.gov (United States)

    Lim, Sanghyun; Lee, Kukjoo; Shin, Inseop; Tron, Artur; Mun, Junyoung; Yim, Taeeun; Kim, Tae-Hyun

    2017-08-01

    The practical applications of Si electrodes in lithium-ion batteries are limited since they undergo large changes in volume during charge and discharge, and consequently become highly deteriorated. A novel binder system holding silicon particles together and preventing disintegration of the electrode during operation hence needs to be developed to enable reliable cycleability. In the current work, such a new polymer binder system, based on poly(acrylic acid) (PAA) and poly(ethylene glycol-co-benzimidazole) (PEGPBI), is developed for silicon anodes. The physical crosslinking using acid-base interactions between PAA and PBI, together with the ion-conducting PEG group, yields physical properties for the resulting PAA-PEGPBI-based anodes that are better than those of electrodes based on the currently available PAA binder, and yields good cell performances. A Si-based electrode with high loading levels of 1.0-1.3 mg cm-2 (0.7-0.91 Si mg cm-2) is reliably manufactured using specifically PAA-PEGPBI-2, which is made with 2 wt% of PEGPBI relative to PAA, and shows a very high capacity value of 1221 mAh g-1 at a rate of 0.5 C after 50 cycles, and a high capacity value of more than 1600 mAh g-1 at a high rate of 2 C.

  16. Microwave preservation method for DMSP, DMSO, and acrylate in unfiltered seawater and phytoplankton culture samples

    National Research Council Canada - National Science Library

    Kinsey, Joanna D; Kieber, David J

    2016-01-01

    ... T ), dimethylsulfoxide (DMSO T ), and acrylate (acrylate T ) concentrations in unfiltered samples to alleviate problems associated with the acidification method when applied to samples containing Phaeocystis . Microwave‐ and acid...

  17. Acute behavioral effects of styrene exposure: a further analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, N.; Rodgers, B.; Venables, H.; Waldron, H.A.; Wells, G.G.

    1981-11-01

    Studies were carried out on two groups to styrene-based resin. Early morning urinary mandelic acid concentrations after two days without exposure correlated with reaction time measured on arrival at work. Men were found to differ considerably in their rate of clearance of mandelic acid-those with slow reaction times. After some months at reduced exposure, a small group of men with previously high mandelic acid concentrations has speeded up on the reaction time task.

  18. Obtention and characterization of acrylic acid-i-polyethylene organometallic copolymers with Mo, Fe, Co, Zn, and Ni; Obtencion y caracterizacion de copolimeros organometalicos de acido acrilico-i-polietileno, con Mo, Fe, Co, Zn y Ni

    Energy Technology Data Exchange (ETDEWEB)

    Dorantes, G.; Urena, F.; Lopez, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Lopez, R. [Universidad Autonoma del Estado de Mexico (Mexico)

    1997-07-01

    In this study a graft acrylic acid (AA) in low density polyethylene (PEBD) copolymers were prepared, using as reaction initiator, gamma radiation at different doses. These copolymers were coordinated with molybdenum, cobalt, iron, zinc and nickel. the obtained polymeric materials were characterized by conventional analysis techniques. It was studied the measurement parameter variation of the positron annihilation when they inter activated with this type of materials and so obtaining information about microstructure of these polymers. (Author)

  19. Preparation of porous carboxymethyl chitosan grafted poly (acrylic acid) superabsorbent by solvent precipitation and its application as a hemostatic wound dressing

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu, E-mail: cylsy@163.com [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Zhang, Yong [School of Life Science, Beijing Institute of Technology, Beijing 100081 (China); Wang, Fengju [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Meng, Weiwei; Yang, Xinlin [School of Life Science, Beijing Institute of Technology, Beijing 100081 (China); Li, Peng [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Jiang, Jianxin [State Key Laboratory of Trauma Burns and Combined Injury, The Third Military Medical University, Chongqing 400042 (China); Tan, Huimin [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Zheng, Yongfa [Guangdong Fuyang Biotechnology Co., Ltd., Heyuan, Guangdong 517000 (China)

    2016-06-01

    The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed. - Highlights: • The novel solvent precipitation method was developed to prepare the porous superabsorbent polymer. • The swelling rate was promoted and the harmful residual monomer was leached after modification. • The modified polymer showed good biological safety. • It showed good hemostasis to arterial hemorrhage model of the animal. • The hemostatic mechanism of the modified superabsorbent polymer was discussed.

  20. In vitro release dynamics of model drugs from psyllium and acrylic acid based hydrogels for the use in colon specific drug delivery.

    Science.gov (United States)

    Singh, Baljit; Bala, Ritu; Chauhan, Nirmala

    2008-08-01

    Psyllium is medicinally important gel forming polysaccharides. Keeping in view, the pharmacological importance of psyllium and drug delivery devices based on hydrogels, psyllium, if suitably tailored to prepare the hydrogels, can act as the double potential candidates for the novel drug delivery systems. Therefore, it is an attempt to prepared psyllium and acrylic acid based pH sensitive novel hydrogels by using N,N'-methylenebisacrylamide (N,N-MBAAm) as crosslinker and ammonium persulfate (APS) as initiator for the use in colon specific drug delivery. The present paper discusses the swelling kinetics of the hydrogels and release dynamics of model drugs (tetracycline hydrochloride, insulin and tyrosine) from drug-loaded hydrogels, for the evaluation of the swelling mechanism and drug release mechanism from the polymeric networks .The effect of pH on the swelling kinetics and release pattern of drugs have been studied by varying the pH of the release medium. It has been observed that swelling and release of drugs from the hydrogels occurred through non-Fickian or anomalous diffusion mechanism in distilled water and pH 7.4 buffer. It shows that the rate of polymer chain relaxation and the rate of drug diffusion from these hydrogels are comparable.

  1. COLLAPSE KINETIC OF COMPOSITES BASED ON COPOLYMERS OF ACRYLIC ACID AND ACRYLAMIDE FILLED WITH BENTONITE IN AQUEOUS SOLUTIONS OF POLYVALENT METALS

    Directory of Open Access Journals (Sweden)

    V. E. Sitnikova

    2017-01-01

    Full Text Available Polymer polyelectrolyte hydrogel composites of acrylic acid and acrylamide copolymer filled with different amounts of bentonite (from 1 to 5 wt.% were synthesized. Collapse kinetics of hydrogel composites was studied in solutions of different concentrations of polyvalent metal salts at a constant temperature of 25 °C. The mass of water given away from hydrogels into the solution was determined by gravimetric method. It has been found that the presence of bentonite in the polyelectrolyte hydrogel composites prevents to some extent collapse in electrolyte solutions, due to steric and electrostatic interactions between the filler particles. These interactions preclude further collapse of hydrogels. The Peleg's kinetic model, most precisely describing experimental data, was applied to calculation of kinetic constants of polymer hydrogels collapse. It is shown that the initial collapse rate and the kinetic constant of collapse and swelling depend non-monotonically on the concentration (ionic strength in the electrolyte solution. At the identical concentration of salts in the solution the kinetic constant of hydrogel collapse is independent of the radius of ions of metals of the studied salts.

  2. "Stable-on-the-Table" Biosensors: Hemoglobin-Poly (Acrylic Acid) Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity.

    Science.gov (United States)

    Ghimire, Ananta; Zore, Omkar V; Thilakarathne, Vindya K; Briand, Victoria A; Lenehan, Patrick J; Lei, Yu; Kasi, Rajeswari M; Kumar, Challa V

    2015-09-18

    In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb) is stabilized by wrapping it in high molecular weight poly(acrylic acid) (PAA, M(W) 450k), and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17-20 psi) without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at -0.279 and -0.334 V in cyclic voltammetry (CV) and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications.

  3. Modification of thermal and rheological behavior of asphalt binder by the addition of an ethylene-methyl acrylate-glycidyl methacrylate terpolymer and polyphosphoric acid

    Directory of Open Access Journals (Sweden)

    Gerson da Silva Pereira

    Full Text Available Abstract This study evaluated the modification effects of adding ethylene-methyl acrylate-glycidyl methacrylate terpolymer (EMGMA in the presence of polyphosphoric acid (PPA to an asphalt binder graded as 50/70 (0.1mm in the Brazilian penetration grade specification (AC 50/70. The EMGMA terpolymer has been presented as a new alternative to modify asphalt binders properties, as scientific literature is scarce on its usage in this context and also on the role of PPA when used in combination with reactive polymers. The characteristics of the modified binder were analyzed by standard and rheological testing, including Multiple Stress Creep Recovery test (MSCR and Fourier Transform Infrared Spectroscopy (FTIR analysis. The MSCR test showed that the modified binder presented lower values of non-recoverable compliances (Jnr and a higher percent recovery, when compared to the conventional binder. This behavior indicates that addition of EMGMA and PPA in asphalt binders could enhance the resistance to rutting of asphalt mixtures. The statistical evaluation showed that EMGMA had greater influence on the studied properties of Jnr (0.1kPa, MSCR recovery, softening point and elastic recovery at 25°C and that the PPA had also significant influence on these properties. FTIR analysis showed that chemical reactions occurred between the asphalt binder and EMGMA, forming a three-dimensional polymeric network, which promotes improved characteristics.

  4. The existence of optimal molecular weight for poly(acrylic acid) binders in silicon/graphite composite anode for lithium-ion batteries

    Science.gov (United States)

    Hu, Bin; Shkrob, Ilya A.; Zhang, Shuo; Zhang, Linghong; Zhang, Jingjing; Li, Yan; Liao, Chen; Zhang, Zhengcheng; Lu, Wenquan; Zhang, Lu

    2018-02-01

    Poly(acrylic acid) (PAA) based binders have been widely used for the high capacity silicon anodes of lithium-ion batteries. While numerous promising progress has been reported, there is no general guideline for choosing the right PAA binders for optimized cycling performance. In this report, aiming to optimize the cycling performance of the Si/graphite composite anodes (15 wt% Si), we systemically investigated a series of PAA binders by validating their molecular weights (MWs) and correlating them to the cycling performance of the anodes fabricated with such binders. The gel permeation chromatography (GPC) was used to validate the MWs of six PAA binders (PAA1 to PAA6). Those binders then underwent a series of characterizations, including rheology study, half-cell cycling, scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR). It is observed that the MWs of PAA binders not only affected the viscosities of the binder solutions but also impacted the cycling performance, possibly due to the cohesion changes. A range of 24-150 kDa is found to be optimal for minimizing the rate and extent of capacity fade and maintaining the cohesion in the electrode matrix despite the dramatic volumetric changes due to Si alloying.

  5. pH Triggered Recovery and Reuse of Thiolated Poly(acrylic acid) Functionalized Gold Nanoparticles with Applications in Colloidal Catalysis.

    Science.gov (United States)

    Ansar, Siyam M; Fellows, Benjamin; Mispireta, Patrick; Mefford, O Thompson; Kitchens, Christopher L

    2017-08-08

    Thiolated poly(acrylic acid) (PAA-SH) functionalized gold nanoparticles were explored as a colloidal catalyst with potential application as a recoverable catalyst where the PAA provides pH-responsive dispersibility and phase transfer capability between aqueous and organic media. This system demonstrates complete nanoparticle recovery and redispersion over multiple reaction cycles without changes in nanoparticle morphology or reduction in conversion. The catalytic activity (rate constant) was reduced in subsequent reactions when recovery by aggregation was employed, despite unobservable changes in morphology or dispersibility. When colloidal catalyst recovery employed a pH induced phase transfer between two immiscible solvents, the catalytic activity of the recovered nanoparticles was unchanged over four cycles, maintaining the original rate constant and 100% conversion. The ability to recover and reuse colloidal catalysts by aggregation/redispersion and phase transfer methods that occur at low and high pH, respectively, could be used for different gold nanoparticle catalyzed reactions that occur at different pH conditions.

  6. In situ synthesis of silver nanoparticles on the cotton fabrics modified by plasma induced vapor phase graft polymerization of acrylic acid for durable multifunction

    Science.gov (United States)

    Wang, C. X.; Ren, Y.; Lv, J. C.; Zhou, Q. Q.; Ma, Z. P.; Qi, Z. M.; Chen, J. Y.; Liu, G. L.; Gao, D. W.; Lu, Z. Q.; Zhang, W.; Jin, L. M.

    2017-02-01

    A practical and ecological method for preparing the multifunctional cotton fabrics with excellent laundering durability was explored. Cotton fabrics were modified by plasma induced vapor phase graft polymerization (PIVPGP) of acrylic acid (AA) and subsequently silver nanoparticles (AgNPs) were in situ synthesized on the treated cotton fabrics. The AgNP loaded cotton fabrics were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), antibacterial activity, self-cleaning activity, thermal stability and laundering durability, respectively. SEM observation and EDX, XPS and XRD analysis demonstrated the much more AgNPs deposition on the cotton fabrics modified by PIVPGP of AA. The AgNP loaded cotton fabrics also exhibited better antibacterial activity, self-cleaning activity, thermal stability and laundering durability. It was concluded that the surface modification of the cotton fabrics by PIVPGP of AA could increase the loading efficiency and binding fastness of AgNPs on the treated cotton fabrics, which could fabricate the cotton fabrics with durable multifunction. In addition, the mechanism of in situ synthesis of AgNPs on the cotton fabrics modified by PIVPGP of AA was proposed.

  7. Study of the adhesive properties versus stability/aging of hernia repair meshes after deposition of RF activated plasma polymerized acrylic acid coating.

    Science.gov (United States)

    Rivolo, Paola; Nisticò, Roberto; Barone, Fabrizio; Faga, Maria Giulia; Duraccio, Donatella; Martorana, Selanna; Ricciardi, Serena; Magnacca, Giuliana

    2016-08-01

    In order to confer adhesive properties to commercial polypropylene (PP) meshes, a surface plasma-induced deposition of poly-(acrylic acid) (PPAA) is performed. Once biomaterials were functionalized, different post-deposition treatments (i.e. water washing and/or thermal treatments) were investigated with the aim of monitoring the coating degradation (and therefore the loss of adhesion) after 3months of aging in both humid/oxidant (air) and inert (nitrogen) atmospheres. A wide physicochemical characterization was carried out in order to evaluate the functionalization effectiveness and the adhesive coating homogeneity by means of static water drop shape analysis and several spectroscopies (namely, FTIR, UV-Visible and X-ray Photoemission Spectroscopy). The modification of the adhesion properties after post-deposition treatments as well as aging under different storage atmospheres were investigated by means of Atomic Force Microscopy (AFM) used in Force/Distance (F/D) mode. This technique confirms itself as a powerful tool for unveiling the surface adhesion capacity as well as the homogeneity of the functional coatings along the fibers. Results obtained evidenced that post-deposition treatments are mandatory in order to remove all oligomers produced during the plasma-treatment, whereas aging tests evidenced that these devices can be simply stored in presence of air for at least three months without a meaningful degradation of the original properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

    Science.gov (United States)

    Dang, Xugang; Chen, Hui; Shan, Zhihua

    2017-07-01

    One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

  9. Poly(acrylic acid)-coated iron oxide nanoparticles: quantitative evaluation of the coating properties and applications for the removal of a pollutant dye.

    Science.gov (United States)

    Fresnais, J; Yan, M; Courtois, J; Bostelmann, T; Bée, A; Berret, J-F

    2013-04-01

    In this work, 6-12 nm iron oxide nanoparticles were synthesized and coated with poly(acrylic acid) chains of molecular weight 2100 g mol(-1). Based on a quantitative evaluation of the dispersions, the bare and coated particles were thoroughly characterized. The number densities of polymers adsorbed at the particle surface and of available chargeable groups were found to be 1.9±0.3 nm(-2) and 26±4 nm(-2), respectively. Occurring via a multi-site binding mechanism, the electrostatic coupling leads to a solid and resilient anchoring of the chains. To assess the efficacy of the particles for pollutant remediation, the adsorption isotherm of methylene blue molecules, a model of pollutant, was determined. The excellent agreement between the predicted and the measured amounts of adsorbed dyes suggests that most carboxylates participate to the complexation and adsorption mechanisms. An adsorption of 830 mg g(-1) was obtained. This quantity compares well with the highest values available for this dye. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Poly(acrylic acid)-regulated Synthesis of Rod-Like Calcium Carbonate Nanoparticles for Inducing the Osteogenic Differentiation of MC3T3-E1 Cells.

    Science.gov (United States)

    Yang, Wei; Yao, Chenxue; Cui, Zhengyang; Luo, Dandan; Lee, In-Seop; Yao, Juming; Chen, Cen; Kong, Xiangdong

    2016-05-06

    Calcium carbonate, especially with nanostructure, has been considered as a good candidate material for bone regeneration due to its excellent biodegradability and osteoconductivity. In this study, rod-like calcium carbonate nanoparticles (Rod-CC NPs) with desired water dispersibility were achieved with the regulation of poly (acrylic acid). Characterization results revealed that the Rod-CC NPs had an average length of 240 nm, a width of 90 nm with an average aspect ratio of 2.60 and a negative ζ-potential of -22.25 ± 0.35 mV. The degradation study illustrated the nanoparticles degraded 23% at pH 7.4 and 45% at pH 5.6 in phosphate-buffered saline (PBS) solution within three months. When cultured with MC3T3-E1 cells, the Rod-CC NPs exhibited a positive effect on the proliferation of osteoblast cells. Alkaline phosphatase (ALP) activity assays together with the osteocalcin (OCN) and bone sialoprotein (BSP) expression observations demonstrated the nanoparticles could induce the differentiation of MC3T3-E1 cells. Our study developed well-dispersed rod-like calcium carbonate nanoparticles which have great potential to be used in bone regeneration.

  11. “Stable-on-the-Table” Biosensors: Hemoglobin-Poly (Acrylic Acid) Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity

    Science.gov (United States)

    Ghimire, Ananta; Zore, Omkar V.; Thilakarathne, Vindya K.; Briand, Victoria A.; Lenehan, Patrick J.; Lei, Yu; Kasi, Rajeswari M.; Kumar, Challa V.

    2015-01-01

    In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb) is stabilized by wrapping it in high molecular weight poly(acrylic acid) (PAA, MW 450k), and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17–20 psi) without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at −0.279 and −0.334 V in cyclic voltammetry (CV) and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications. PMID:26393601

  12. Preparation of nanogels by radiation-induced cross-linking of interpolymer complexes of poly (acrylic acid) with poly (vinyl pyrrolidone) in aqueous medium

    Science.gov (United States)

    Ghaffarlou, Mohammadreza; Sütekin, S. Duygu; Güven, Olgun

    2018-01-01

    Functional nanogels were prepared from interpolymer complexes (IPC) of poly (vinyl pyrrolidone) and poly (acrylic acid) by gamma irradiation of their aqueous solutions. The coil size of IPCs prepared under different experimental conditions (polymer molecular weight, concentration, mixing ratios, pH and temperature) were measured by Dynamic Light Scattering (DLS) technique prior to irradiation. At relatively low absorbed doses of 5 and 10 kGy, IPC nanogels with a range of 30-250 nm diameters, -12 to -28 mV zeta potentials and polydispersities lower than 0.17 were obtained. The sizes of the nanogels were found to be smaller than the size of the precursor IPC coil sizes (40-300 nm) due to the formation of intra-chain crosslinks. Thus a recipe of preparing multifunctional nanogels with double amphiphilic properties carrying polyacidic and nonionic polymer structures with the range of above listed properties has been developed. These nanogels show narrow size distribution and high colloidal stability increasing their potential to be used as biocompatible drug carriers with controlled-release properties. PVP-PAA IPC nanogels were characterized by dynamic light scattering (DLS), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques.

  13. Preparation by Poly(Acrylic Acid) Sol-Gel Method and Thermoelectric Properties of γ-Na x CoO2 Bulk Materials

    Science.gov (United States)

    Li, Xiaoyu; Zhang, Li; Tang, Xinfeng

    2017-11-01

    γ-Na x CoO2 single-phase powders have been synthesized by a poly(acrylic acid) (PAA) sol-gel (SG) method, and γ-Na x CoO2 bulk ceramic fabricated using spark plasma sintering. The effects of the PAA concentration on the sample phase composition and morphology were investigated. The thermoelectric properties of the γ-Na x CoO2 bulk ceramic were also studied. The results show that the PAA concentration did not significantly affect the crystalline phase of the product. However, agglomeration of γ-Na x CoO2 crystals was suppressed by the steric effect of PAA. The Na x CoO2 bulk ceramic obtained using the PAA SG method had higher crystallographic anisotropy, better chemical homogeneity, and higher density than the sample obtained by solid-state reaction (SSR), leading to improved thermoelectric performance. The PAA SG sample had power factor (in-plane PF = σS 2) of 0.61 mW m-1 K-2 and dimensionless figure of merit ( ZT) along the in-plane direction of 0.19 at 900 K, higher than for the SSR sample (in-plane PF = 0.51 mW m-1 K-2, in-plane ZT = 0.17). These results demonstrate that a simple and feasible PAA SG method can be used for synthesis of Na x CoO2 ceramics with improved thermoelectric properties.

  14. Preparation and characterization of pH-sensitive and antifouling poly(vinylidene fluoride) microfiltration membranes blended with poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid).

    Science.gov (United States)

    Ju, Junping; Wang, Chao; Wang, Tingmei; Wang, Qihua

    2014-11-15

    Functional terpolymer of poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid) (P(MMA-HEMA-AA)) was synthesized via a radical polymerization method. The terpolymer could be directly blended with poly(vinylidene fluoride) (PVDF) to prepare the microfiltration (MF) membranes via phase separate process. The synthesized polymers were characterized by Fourier transform infrared (FTIR), the nuclear magnetic resonance proton spectra ((1)H NMR). The membrane had the typical asymmetric structure and the hydrophilic side chains tended to aggregate on the membrane surface. The surface enrichment of amphiphilic copolymer and morphology of MF membranes were characterized by Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). The contact angle (CA) and water uptake were also tested to assess the hydrophilicity and wetting characteristics of the polymer surface. The water filtration properties were measured. It was found the modified membranes showed excellent pH-sensitivity and pH-reversibility behavior. Furthermore, the hydrophilicity of the blended membranes increased, and the membranes showed good protein antifouling property. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Poly(acrylic acid-regulated Synthesis of Rod-Like Calcium Carbonate Nanoparticles for Inducing the Osteogenic Differentiation of MC3T3-E1 Cells

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2016-05-01

    Full Text Available Calcium carbonate, especially with nanostructure, has been considered as a good candidate material for bone regeneration due to its excellent biodegradability and osteoconductivity. In this study, rod-like calcium carbonate nanoparticles (Rod-CC NPs with desired water dispersibility were achieved with the regulation of poly (acrylic acid. Characterization results revealed that the Rod-CC NPs had an average length of 240 nm, a width of 90 nm with an average aspect ratio of 2.60 and a negative ζ-potential of −22.25 ± 0.35 mV. The degradation study illustrated the nanoparticles degraded 23% at pH 7.4 and 45% at pH 5.6 in phosphate-buffered saline (PBS solution within three months. When cultured with MC3T3-E1 cells, the Rod-CC NPs exhibited a positive effect on the proliferation of osteoblast cells. Alkaline phosphatase (ALP activity assays together with the osteocalcin (OCN and bone sialoprotein (BSP expression observations demonstrated the nanoparticles could induce the differentiation of MC3T3-E1 cells. Our study developed well-dispersed rod-like calcium carbonate nanoparticles which have great potential to be used in bone regeneration.

  16. Silicone/Acrylate Copolymers

    Science.gov (United States)

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  17. Organocatalytic chemo- and regioselective oxyarylation of styrenes via a cascade reaction: remote activation of hydroxyl groups.

    Science.gov (United States)

    Zhang, Yu-Chen; Jiang, Fei; Wang, Shu-Liang; Shi, Feng; Tu, Shu-Jiang

    2014-07-03

    The first organocatalytic oxyarylation of styrenes has been established through a cascade of vinylogous Michael addition/alkoxyl transfer reactions of o- or p-hydroxylstyrenes with quinone imine ketals. The process leads to a highly chemo- and regioselective oxyarylation of styrenes and provides access to m-alkylated anilines in generally high yields and excellent diastereoselectivity (up to 99% yield, >95:5 dr). An investigation of the reaction pathway revealed that the existence and position of the hydroxyl group of styrene played crucial roles in the cascade reaction, suggesting that the two reactants were simultaneously activated by binaphthyl-derived phosphoric acid via hydrogen bonding interactions and long-distance conjugative effects. In addition, the activating group of the hydroxyl functionality in the products can be easily removed or transformed, demonstrating the applicability and utility of this strategy in styrene oxyarylation and in the synthesis of styrene-based compounds.

  18. Synthesis and Characterization of Acrylic-Based Photopolymer as a Candidate for Denture Base Material

    Science.gov (United States)

    Wicaksono, S. T.; Rasyida; Ardhyananta, H.

    2017-05-01

    Denture base is a denture part that rests on the soft tissue covering the jawbone and becomes an anchor of a denture. The material that commonly used for this purpose is poly (methyl methacrylate). However, it lacks in mechanical properties due to high water absorption. The aim of this research was to improve the physical and mechanical properties of poly (methyl methacrylate) by making a copolymer with styrene via photopolymerization process. In this method was used the addition of styrene monomer at 10, 20, 30, 40, and 50 wt% into the acrylic resin to form copolymer materials via photopolymerization process. The amount of 1.5 wt% Irgacure 784’s photoinitiator was added as a photoinitiator. The results showed that the addition of 40% by weight of styrene copolymer is the best performance compare to the addition styrene of 10, 20, 30, and 50%. The samples with an addition styrene of 40 wt% showed excellent properties such as high water absorption value of 2.405 μg/mm3, the solubility of 0.434 μg/mm3, the flexural strength of 69.336 MPa, a flexural modulus of 1.236 GPa, and a hardness value of 82.583 HD. Poly (methyl methacrylate-co-styrene) copolymer with the addition of styrene 40 wt% has the closest value to the requirements for a denture base material.

  19. Trends in occupational exposure to styrene in the European glass fibre-reinforced plastics industry.

    Science.gov (United States)

    Van Rooij, J G M; Kasper, A; Triebig, G; Werner, P; Jongeneelen, F J; Kromhout, H

    2008-07-01

    This study presents temporal trends of styrene exposure for workers in the European glass fibre-reinforced plastics (GRP) industry during the period 1966-2002. Data of personal styrene exposure measurements were retrieved from reports, databases and peer-reviewed papers. Only sources with descriptive statistics of personal measurements were accepted. The styrene exposure data cover personal air samples and biological monitoring data, that is, urinary styrene metabolites (mandelic acid and/or phenylglyoxylic acid) and styrene in blood. Means of series of measurements were categorized by year, country, production process, job and sampling strategy. Linear mixed models were used to identify temporal trends and factors affecting exposure levels. Personal exposure measurements were available from 60 reports providing data on 24145 1-8-h time-weighted average shift personal air samples. Available data of biological exposure indicators included measurements of mandelic acid in post-shift urine (6361 urine samples being analysed). Trend analyses of the available styrene exposure data showed that the average styrene concentration in the breathing zone of open-mould workers in the European GRP industry has decreased on average by 5.3% per year during the period 1966-1990 and by only 0.4% annually in the period after 1990. The highest exposures were measured in Southern Europe and the lowest exposures in Northern Europe with Central Europe in between. Biological indicators of styrene (mandelic acid in post-shift urine) showed a somewhat steeper decline (8.9%), most likely because urine samples were collected in companies that showed a stronger decrease of styrene exposure in air than GRP companies where no biological measurements were carried out.

  20. Waterborne hyperbranched alkyd-acrylic resin obtained by miniemulsion polymerization

    Directory of Open Access Journals (Sweden)

    Edwin Murillo

    Full Text Available Abstract Four waterborne hyperbranched alkyd-acrylic resins (HBRAA were synthesized by miniemulsion polymerization from a hyperbranched alkyd resin (HBR, methyl methacrylate (MMA, butyl acrylate (BA and acrylic acid (AA, by using benzoyl peroxide (BPO and ammonium persulfate (AP as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC, nuclear magnetic resonance (NMR and gel permeation chromatography (GPC. The conversion percentage, glass transition temperature (Tg, content of acrylic polymer (determined by soxhlet extraction and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly monomodal. The film properties (gloss, flexibility, adhesion and drying time of the HBRAA were good.

  1. One-step routes from di- and triblock copolymer precursors to hydrophilic nanoporous poly(acrylic acid)-b-polystyrene

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars

    2008-01-01

    at the same time part of the nanoporosity, and PDMS was quantitatively etched to provide additional nanoporosity. Both the deprotection of the PtBA block and the etching of PDMS were realized by one-step operations using either anhydrous hydrogen fluoride (HF) or trifluoroacetic acid (TFA). The finding......, and scanning electron microscopy. In contact with water, all the prepared nanoporous polymers showed spontaneous water uptake close to the amounts expected from the precursor block copolymer compositions....

  2. Formation of styrene dependent on fermentation management during wheat beer production.

    Science.gov (United States)

    Schwarz, Katrin J; Stübner, René; Methner, Frank-Jürgen

    2012-10-15

    Styrene is formed by the thermal decarboxylation of cinnamic acid during wort boiling or by enzymatic decarboxylation during fermentation. The enzymatic reactions proceed in parallel to the decarboxylation of ferulic- and p-cumaric acid to 4-vinylguaiacol and 4-vinylphenol by the same decarboxylase enzyme. However, the formation of styrene occurs much faster and all available cinnamic acid in wort was converted completely within a few hours. Moreover, the comparison of various manufacturing parameters shows that a higher fermentation temperature of 25 °C compared to 16 °C and an open fermentation management lead to a rapid decrease of styrene. This allows minimising the content of styrene in beer while maintaining the typical wheat beer flavours. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Amphiphilic copolymers based on PEG-acrylate as surface active water viscosifiers : Towards new potential systems for enhanced oil recovery

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    2016-01-01

    With the purpose of investigating new potential candidates for enhanced oil recovery (EOR), amphiphilic copolymers based on Poly(ethylene glycol) methyl ether acrylate (PEGA) have been prepared by Atom Transfer Radical Polymerization (ATRP). A P(PEGA) homopolymer, a block copolymer with styrene

  4. Low level occupational exposure to styrene: its effects on DNA damage and DNA repair.

    Science.gov (United States)

    Wongvijitsuk, Sirilak; Navasumrit, Panida; Vattanasit, Udomratana; Parnlob, Varabhorn; Ruchirawat, Mathuros

    2011-03-01

    The present study aimed to evaluate the effects of styrene exposure at levels below the recommended standards of the Threshold Limit Value (TLV-TWA(8)) of 20 ppm (ACGIH, 2004) in reinforced-fiberglass plastics workers. Study subjects comprised 50 exposed workers and 40 control subjects. The exposed workers were stratified by styrene exposure levels, i.e. group I (20 ppm, >84.40 mg/m(3)). The mean styrene exposure levels of exposed workers were significantly higher than those of the control workers. Biomarkers of exposure to styrene, including blood styrene and the urinary metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA), were significantly increased with increasing levels of styrene exposure, but were not detected in the control group. DNA damage, such as DNA strand breaks, 8-hydroxydeoxyguanosine (8-OHdG), and DNA repair capacity, were used as biomarkers of early biological effects. DNA strand breaks and 8-OHdG/10(5)dG levels in peripheral leukocytes of exposed groups were significantly higher compared to the control group (Prisk from occupational styrene exposure, even at levels below the recommended TLV-TWA(8) of 20 ppm. Copyright © 2010 Elsevier GmbH. All rights reserved.

  5. Direct methanol fuel cell based on poly(vinyl alcohol)/titanium oxide nanotubes/poly(styrene sulfonic acid) (PVA/nt-TiO 2/PSSA) composite polymer membrane

    Science.gov (United States)

    Yang, Chun-Chen; Chien, Wen-Chen; Li, Yingjeng James

    The high performance poly(vinyl alcohol)/titanium oxide nanotubes/poly(styrene sulfonic acid) (PVA/nt-TiO 2/PSSA) proton-conducting composite membrane is prepared by a solution casting method. The characteristic properties of these blend composite membranes are investigated by thermal gravimetric analysis (TGA), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), micro-Raman spectroscopy, dynamic mechanical analysis (DMA), methanol permeability measurement and AC impedance method. It is found that the peak power densities of the DMFC with 1, 2, and 4 M CH 3OH fuels are 12.85, 23.72, and 10.99 mW cm -2, respectively, at room temperature and ambient air. Especially, among three methanol concentrations, the 2 M methanol shows the highest peak power density among three methanol concentrations. The results indicate that the air-breathing direct methanol fuel cell comprised of a novel PVA/nt-TiO 2/PSSA composite polymer membrane has excellent electrochemical performance and stands out as a viable candidate for applications in DMFC.

  6. Hydrophilic surface modification of acrylate-based biomaterials.

    Science.gov (United States)

    Arnal-Pastor, M; Comín-Cebrián, S; Martínez-Ramos, C; Monleón Pradas, M; Vallés-Lluch, A

    2016-04-01

    Acrylic polymers have proved to be excellent with regard to cell adhesion, colonization and survival, in vitro and in vivo. Highly ordered and regular pore structures thereof can be produced with the help of polyamide templates, which are removed with nitric acid. This treatment converts a fraction of the ethyl acrylate side groups into acrylic acid, turning poly(ethyl acrylate) scaffolds into a more hydrophilic and pH-sensitive substrate, while its good biological performance remains intact. To quantify the extent of such a modification, and be able to characterize the degree of hydrophilicity of poly(ethyl acrylate), poly(ethyl acrylate) was treated with acid for different times (four, nine and 17 days), and compared with poly(acrylic acid) and a 90/10%wt. EA/AAc copolymer (P(EA-co-AAc)). The biological performance was also assessed for samples immersed in acid up to four days and the copolymer, and it was found that the incorporation of acidic units on the material surface was not prejudicial for cells. This surface modification of 3D porous hydrophobic scaffolds makes easier the wetting with culture medium and aqueous solutions in general, and thus represents an advantage in the manageability of the scaffolds. © The Author(s) 2016.

  7. Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)-poly(vinyl alcohol)/poly(acrylic acid) interpenetrating polymer networks for improving optrode-neural tissue interface in optogenetics.

    Science.gov (United States)

    Lu, Yi; Li, Yanling; Pan, Jianqing; Wei, Pengfei; Liu, Nan; Wu, Bifeng; Cheng, Jinbo; Lu, Caiyi; Wang, Liping

    2012-01-01

    The field of optogenetics has been successfully used to understand the mechanisms of neuropsychiatric diseases through the precise spatial and temporal control of specific groups of neurons in a neural circuitry. However, it remains a great challenge to integrate optogenetic modulation with electrophysiological and behavioral read out methods as a means to explore the causal, temporally precise, and behaviorally relevant interactions of neurons in the specific circuits of freely behaving animals. In this study, an eight-channel chronically implantable optrode array was fabricated and modified with poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate)-poly(vinyl alcohol)/poly(acrylic acid) interpenetrating polymer networks (PEDOT/PSS-PVA/PAA IPNs) for improving the optrode-neural tissue interface. The conducting polymer-hydrogel IPN films exhibited a significantly higher capacitance and lower electrochemical impedance at 1 kHz as compared to unmodified optrode sites and showed significantly improved mechanical and electrochemical stability as compared to pure conducting polymer films. The cell attachment and neurite outgrowth of rat pheochromocytoma (PC12) cells on the IPN films were clearly observed through calcein-AM staining. Furthermore, the optrode arrays were chronically implanted into the hippocampus of SD rats after the lentiviral expression of synapsin-ChR2-EYFP, and light-evoked, frequency-dependant action potentials were obtained in freely moving animals. The electrical recording results suggested that the modified optrode arrays showed significantly reduced impedance and RMS noise and an improved SNR as compared to unmodified sites, which may have benefited from the improved electrochemical performance and biocompatibility of the deposited IPN films. All these characteristics are greatly desired in optogenetic applications, and the fabrication method of conducting polymer-hydrogel IPNs can be easily integrated with other modification methods to build a

  8. Physicochemical properties of pH-controlled polyion complex (PIC) micelles of poly(acrylic acid)-based double hydrophilic block copolymers and various polyamines.

    Science.gov (United States)

    Warnant, J; Marcotte, N; Reboul, J; Layrac, G; Aqil, A; Jerôme, C; Lerner, D A; Gérardin, C

    2012-05-01

    The physicochemical properties of polyion complex (PIC) micelles were investigated in order to characterize the cores constituted of electrostatic complexes of two oppositely charged polyelectrolytes. The pH-sensitive micelles were obtained with double hydrophilic block copolymers containing a poly(acrylic acid) block linked to a modified poly(ethylene oxide) block and various polyamines (polylysine, linear and branched polyethyleneimine, polyvinylpyridine, and polyallylamine). The pH range of micellization in which both components are ionized was determined for each polyamine. The resulting PIC micelles were characterized using dynamic light scattering and small-angle X-ray scattering experiments (SAXS). The PIC micelles presented a core-corona nanostructure with variable polymer density contrasts between the core and the corona, as revealed by the analysis of the SAXS curves. It was shown that PIC micelle cores constituted by polyacrylate chains and polyamines were more or less dense depending on the nature of the polyamine. It was also determined that the density of the cores of the PIC micelles depended strongly on the nature of the polyamine. These homogeneous cores were surrounded by a large hairy corona of hydrated polyethylene oxide block chains. Auramine O (AO) was successfully entrapped in the PIC micelles, and its fluorescence properties were used to get more insight on the core properties. Fluorescence data confirmed that the cores of such micelles are quite compact and that their microviscosity depended on the nature of the polyamine. The results obtained on these core-shell micelles allow contemplating a wide range of applications in which the AO probe would be replaced by various cationic drugs or other similarly charged species to form drug nanocarriers or new functional nanodevices.

  9. Ingenious route for ultraviolet-induced graft polymerization achieved on inorganic particle: Fabricating magnetic poly(acrylic acid) densely grafted nanocomposites for Cu{sup 2+} removal

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Qi, E-mail: roundzking@163.com [School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444 (China); Luo, Wenjun [Faculty of Material and Chemistry, China University of Geosciences, Wuhan, 430074 (China); Zhang, Xing [School of Environmental and Chemical Engineering, Shanghai University, 333 Nanchen Road, Shanghai, 200444 (China)

    2017-08-15

    Highlights: • A novel PAA brushes-decorated magnetic adsorbent was prepared successfully. • The preparation approach was simple, rapid, and efficient. • Densely polymer grafting can be achieved on inorganic substrate by the method. • The g-MNPs exhibits an outstanding adsorption performance for Cu{sup 2+}. • The Cu{sup 2+}-saturated adsorbent can be separated and regenerated easily. - Abstract: In this study, ultraviolet (UV)-induced graft technology is improved to be successfully applied on inorganic substrate for fabricating a novel poly(acrylic acid) (PAA) brushes-decorated magnetic nano-composite particles (g-MNPs) as a potential adsorbent toward Cu{sup 2+} ion. The most fascinating features of the resultant g-MNPs are the abundant and highly accessible carboxyl groups present in PAA brushes and the rapid separation from the medium by magnetic field after adsorption. Through the new and high-efficiency surface-initiated polymerization route, the densely PAA brushes was successfully immobilized on the MNPs surface with a high grafting yield of 88.3%. Excitingly, the g-MNPs exhibited an exceptional performance for Cu{sup 2+} adsorption, e.g., ultrahigh adsorption capacity (up to 152.1 mg g{sup −1}), rapid adsorption rate (within 30 min) and low residual concentration (below 1.3 ppm). Full kinetic and isotherm analysis as well as thermodynamic study were also undertaken, the results showed that Cu{sup 2+} adsorption followed Langmuir isotherm and the pseudo-second-order kinetic model, the adsorption rate was controlled by two sequential periods of external and intraparticle diffusion. According to the calculated value of thermodynamic parameters, the Cu{sup 2+} adsorption onto g-MNPs was a spontaneous endothermic process. Furthermore, the excellent reusability of the resultant adsorbent was also confirmed, which can keep above 95% adsorption capacity and desorption rate in 8 consecutive cycles.

  10. In situ synthesis of silver nanoparticles on the cotton fabrics modified by plasma induced vapor phase graft polymerization of acrylic acid for durable multifunction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu, 224003 (China); Collaborative Innovation Center for Ecological Building, Materials and Environmental Protection Equipments, Jiangsu, 224051 (China); Laboratory for Advanced Technology in Environmental Protection, Jiangsu, 224051 (China); School of Textile and Clothing, Nantong University, Jiangsu, 226019 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu, 226019 (China); Lv, J.C.; Zhou, Q.Q.; Ma, Z.P.; Qi, Z.M.; Chen, J.Y.; Liu, G.L.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu, 224003 (China); Lu, Z.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu, 224003 (China); Collaborative Innovation Center for Ecological Building, Materials and Environmental Protection Equipments, Jiangsu, 224051 (China); Laboratory for Advanced Technology in Environmental Protection, Jiangsu, 224051 (China); Zhang, W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu, 224003 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201204 (China)

    2017-02-28

    Highlights: • A new means for multifunctional cotton fabrics by PIVPGP of AA and AgNPs synthesis. • Surface modification by PIVPGP of AA had a positive effect on AgNPs loading. • Antibacterial, self-cleaning and thermal stability were greatly improved. • AgNP loaded cotton fabric exhibited excellent laundering durability. • Mechanism of AgNPs in situ synthesis on cotton fabrics by PIVPGP of AA was proposed. - Abstract: A practical and ecological method for preparing the multifunctional cotton fabrics with excellent laundering durability was explored. Cotton fabrics were modified by plasma induced vapor phase graft polymerization (PIVPGP) of acrylic acid (AA) and subsequently silver nanoparticles (AgNPs) were in situ synthesized on the treated cotton fabrics. The AgNP loaded cotton fabrics were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), antibacterial activity, self-cleaning activity, thermal stability and laundering durability, respectively. SEM observation and EDX, XPS and XRD analysis demonstrated the much more AgNPs deposition on the cotton fabrics modified by PIVPGP of AA. The AgNP loaded cotton fabrics also exhibited better antibacterial activity, self-cleaning activity, thermal stability and laundering durability. It was concluded that the surface modification of the cotton fabrics by PIVPGP of AA could increase the loading efficiency and binding fastness of AgNPs on the treated cotton fabrics, which could fabricate the cotton fabrics with durable multifunction. In addition, the mechanism of in situ synthesis of AgNPs on the cotton fabrics modified by PIVPGP of AA was proposed.

  11. Ear-like poly (acrylic acid)-activated carbon nanocomposite: A highly efficient adsorbent for removal of Cd(II) from aqueous solutions.

    Science.gov (United States)

    Ge, Huacai; Wang, Jincui

    2017-02-01

    Poly (acrylic acid) modified activated carbon nanocomposite (PAA-AC) was synthesized. The structure and morphology of this nanocomposite were characterized by FTIR, SEM, TEM, XRD and Zeta potential. The adsorption of some heavy metal ions on PAA-AC was studied. The characterization results indicated that PAA-AC was a novel and ear-like nanosheet material with the thickness of about 40 nm and the diameter of about 300 nm. The adsorption results exhibited that the introduction of carboxyl groups into activated carbon evidently increased the uptake for heavy metal ions and the nanocomposite had maximum uptake for Cd(II). Various variables affecting adsorption of PAA-AC for Cd(II) were systematically explored. The maximum capacity and equilibrium time for adsorption of Cd(II) by PAA-AC were 473.2 mg g(-1) and 15 min. Moreover, the removal of Cd(II) for real electroplating wastewater by PAA-AC could reach 98.5%. These meant that the removal of Cd(II) by PAA-AC was highly efficient and fast. The sorption kinetics and isotherm fitted well with the pseudo-second-order model and Langmuir model, respectively. The adsorption mainly was a chemical process by chelation. Thermodynamic studies revealed that the adsorption was a spontaneous and endothermic process. The results revealed that PAA-AC could be considered as a potential candidate for Cd(II) removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Study of the adhesive properties versus stability/aging of hernia repair meshes after deposition of RF activated plasma polymerized acrylic acid coating

    Energy Technology Data Exchange (ETDEWEB)

    Rivolo, Paola [Politecnico di Torino, Department of Applied Science and Technology, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Nisticò, Roberto, E-mail: roberto.nistico@unito.it [University of Torino, Department of Chemistry and NIS Centre, Via P. Giuria 7, 10125 Torino (Italy); Barone, Fabrizio [University of Torino, Department of Chemistry and NIS Centre, Via P. Giuria 7, 10125 Torino (Italy); Faga, Maria Giulia; Duraccio, Donatella [CNR-IMAMOTER, Strada delle Cacce 73, 10135 Torino (Italy); Martorana, Selanna [Herniamesh S.r.l., Via F.lli Meliga 1/C, 10034 Chivasso (Italy); Ricciardi, Serena [Politecnico di Torino, Department of Applied Science and Technology, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Magnacca, Giuliana [University of Torino, Department of Chemistry and NIS Centre, Via P. Giuria 7, 10125 Torino (Italy)

    2016-08-01

    In order to confer adhesive properties to commercial polypropylene (PP) meshes, a surface plasma-induced deposition of poly-(acrylic acid) (PPAA) is performed. Once biomaterials were functionalized, different post-deposition treatments (i.e. water washing and/or thermal treatments) were investigated with the aim of monitoring the coating degradation (and therefore the loss of adhesion) after 3 months of aging in both humid/oxidant (air) and inert (nitrogen) atmospheres. A wide physicochemical characterization was carried out in order to evaluate the functionalization effectiveness and the adhesive coating homogeneity by means of static water drop shape analysis and several spectroscopies (namely, FTIR, UV–Visible and X-ray Photoemission Spectroscopy). The modification of the adhesion properties after post-deposition treatments as well as aging under different storage atmospheres were investigated by means of Atomic Force Microscopy (AFM) used in Force/Distance (F/D) mode. This technique confirms itself as a powerful tool for unveiling the surface adhesion capacity as well as the homogeneity of the functional coatings along the fibers. Results obtained evidenced that post-deposition treatments are mandatory in order to remove all oligomers produced during the plasma-treatment, whereas aging tests evidenced that these devices can be simply stored in presence of air for at least three months without a meaningful degradation of the original properties. - Highlights: • Plasma polymerized surface functionalization of hernia-repair meshes was used to confer adhesive properties. • The stability of the adhesive coating was verified under different post-deposition conditions. • The use of AFM in F/D mode was selected to monitor the coating degradation.

  13. Novel azo-peresters radical initiators used for the synthesis of acrylic pressure-sensitive adhesives

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available Acrylic pressure-sensitive adhesives (PSA based on two monomers: 2-ethylhexyl acrylate and acrylic acid were synthesized in organic solvent ethyl acetate using AIBN (2, 2'-azo-diisobutyronitrile and new synthesized azo-peresters as radical initiators. After polymerization the viscosity, molecular weight and polydispersity of synthesized acrylic PSA were evaluated. The novel synthesized radical azo-perester initiators were synthesized, isolated and compared with industrial predominant usable azo-initiator AIBN.

  14. Surface functionalisation of polypropylene hernia-repair meshes by RF-activated plasma polymerisation of acrylic acid and silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nisticò, Roberto, E-mail: roberto.nistico@unito.it [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy); Rosellini, Andrea [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy); Rivolo, Paola [Politecnico di Torino, Dipartimento di Scienza Applicata e Tecnologia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Faga, Maria Giulia [CNR-IMAMOTER, Strada delle Cacce 73, 10135 Torino (Italy); Lamberti, Roberta; Martorana, Selanna [Herniamesh S.r.l., Via F.lli Meliga 1/C, 10034 Chivasso (Italy); Castellino, Micaela [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Virga, Alessandro; Mandracci, Pietro [Politecnico di Torino, Dipartimento di Scienza Applicata e Tecnologia, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Malandrino, Mery; Magnacca, Giuliana [University of Torino, Department of Chemistry and NIS Research Centre, Via P. Giuria 7, 10125 Torino (Italy)

    2015-02-15

    Graphical abstract: - Highlights: • Polypropylene meshes for hernioplasty were surface functionalised via plasma-polymerisation to confer adhesive properties. • Subsequently, silver nanoparticles were loaded to add antibacterial activity. • Materials were physico-chemical characterised and adhesive properties evaluated. - Abstract: Hernia diseases are among the most common and diffuse causes of surgical interventions. Unfortunately, still nowadays there are different phenomena which can cause the hernioplasty failure, for instance post-operative prostheses displacements and proliferation of bacteria in the surgical site. In order to limit these problems, commercial polypropylene (PP) and polypropylene/Teflon (PP/PTFE) bi-material meshes were surface functionalised to confer adhesive properties (and therefore reduce undesired displacements) using polyacrylic acid synthesized by plasma polymerisation (PPAA). A broad physico-chemical and morphological characterisation was carried out and adhesion properties were investigated by means of atomic force microscopy (AFM) used in force/distance (F/D) mode. Once biomedical devices surface was functionalised by PPAA coating, metallic silver nanoparticles (AgNPs) with antimicrobial properties were synthesised and loaded onto the polymeric prostheses. The effect of the PPAA, containing carboxylic functionalities, adhesive coating towards AgNPs loading capacity was verified by means of X-ray photoelectron spectroscopy (XPS). Preliminary measurement of the Ag loaded amount and release in water were also investigated via inductively coupled plasma atomic emission spectroscopy (ICP-AES). Promising results were obtained for the functionalised biomaterials, encouraging future in vitro and in vivo tests.

  15. Analytical investigations of poly(acrylic acid) coatings electrodeposited on titanium-based implants: a versatile approach to biocompatibility enhancement.

    Science.gov (United States)

    De Giglio, E; Cometa, S; Cioffi, N; Torsi, L; Sabbatini, L

    2007-12-01

    A polyacrylic acid film was synthesized on titanium substrates from aqueous solutions via an electroreductive process for the first time. This work was done in order to develop a versatile coating for titanium-based orthopaedic implants that acts as both an effective bioactive surface and an effective anti-corrosion barrier. The chemical structure of the PAA coating was investigated by X-ray photoelectron spectroscopy (XPS). Scanning electron microscopy (SEM) was employed to evaluate the effect of annealing treatment on the morphology of the coatings in terms of their uniformity and porosity. Inductively coupled plasma mass spectrometry was used to measure ion concentrations in ion release tests performed on Ti-6Al-4V sheets modified with PAA coatings (annealed and unannealed). Results indicate that the annealing process produces coatings that possess considerable anti-corrosion performance. Moreover, the availability and the reactivity of the surface carboxylic groups were exploited in order to graft biological molecules onto the PAA-modified titanium implants. The feasibility of the grafting reaction was tested using a single aminoacid residue. A fluorinated aminoacid was selected, and the grafting reaction was monitored both by XPS, using fluorine as a marker element, and via quartz crystal microbalance (QCM) measurements. The success of the grafting reaction opens the door to the synthesis of a wide variety of PAA-based coatings that are functionalized with selected bioactive molecules and promote positive reactions with the biological system interfacing the implant while considerably reducing ion release into surrounding tissues.

  16. Nano-emulsion based on acrylic acid ester co-polymer derivatives as an efficient pre-tanning agent for buffalo hide

    Directory of Open Access Journals (Sweden)

    Farouk Abd El-Monem

    2017-05-01

    Full Text Available Acrylic copolymer nanoemulsions were prepared based on methyl methacrylate (MMA and butyl acrylate (BA. The prepared acrylic copolymer emulsions were characterized using solid content, rheological properties, molecular weight, MFFT and TEM. The prepared polymers were used as pre-tanning of the depickled hide to enhance the physico-mechanical properties of tanned leather. The key parameters which affect exhaustion and fixation of chrome tan as well as shrinkage temperature of the tanned leather were studied and evaluated using SEM, shrinkage temperature and the mechanical properties of the pre-tanned leather. The results showed that, the prepared polymers A & C are the best polymers in improving the physical properties of the treated leather. Furthermore, the shrinkage temperature and the mechanical properties of the tanned leather were improved. In addition, a significant enhancement in the texture of the leather treated by the polymers was noticed as proved by scanning electron microscopy (SEM.

  17. The influence of polymer topology on pharmacokinetics: differences between cyclic and linear PEGylated poly(acrylic acid) comb polymers.

    Science.gov (United States)

    Chen, Bo; Jerger, Katherine; Fréchet, Jean M J; Szoka, Francis C

    2009-12-16

    Water-soluble polymers for the delivery of chemotherapeutic drugs passively target solid tumors as a consequence of reduced renal clearance and the enhanced permeation and retention (EPR) effect. Elimination of the polymers in the kidney occurs due to filtration through biological nanopores with a hydrodynamic diameter comparable to the polymer. Therefore we have investigated chemical features that may broadly be grouped as "molecular architecture" such as: molecular weight, chain flexibility, number of chain ends and branching, to learn how they impact polymer elimination. In this report we describe the synthesis of four pairs of similar molecular weight cyclic and linear polyacrylic acid polymers grafted with polyethylene glycol (23, 32, 65, 114 kDa) with low polydispersities using ATRP and "click" chemistry. The polymers were radiolabeled with (125)I and their pharmacokinetics and tissue distribution after intravenous injection were determined in normal and C26 adenocarcinoma tumored BALB/c mice. Cyclic polymers above the renal threshold of 30 kDa had a significantly longer elimination time (between 10 and 33% longer) than did the comparable linear polymer (for the 66 kDa cyclic polymer, t(1/2,beta)=35+/-2 h) and a greater area under the serum concentration versus time curve. This resulted in a greater tumor accumulation of the cyclic polymer than the linear polymer counterpart. Thus water-soluble cyclic comb polymers join a growing list of polymer topologies that show greatly extended circulation times compared to their linear counterparts and provide alternative polymer architecture for use as drug carriers.

  18. Exposure to styrene in fiberglass-reinforced plastic manufacture: still a problem.

    Science.gov (United States)

    Papaleo, Bruno; Caporossi, Lidia; Bernardini, Francesca; Cristadoro, Luisa; Bastianini, Lucia; De Rosa, Mariangela; Capanna, Silvia; Marcellini, Laura; Loi, Francesco; Battista, Giuseppe

    2011-11-01

    The aim of the work is to define occupational exposure to styrene in fiberglass manufacture; the phase of stretching styrene resins needs some manual handling and leads workers to be exposed to styrene. We surveyed 20 workers in two companies manufacturing fiberglass, checking environmental levels and urinary concentrations of mandelic acid (MA), and phenylglioxylic acid (PGA). Workers completed a questionnaire collecting their medical history. Environmental monitoring showed some styrene concentrations higher than the threshold limit value-time-weighted average. Biological monitoring confirmed these findings and four workers had levels of urinary PGA and MA concentrations higher than the Biological Exposure Indices of the American Conference of Governmental Industrial Hygienists. This picture confirms that, even though the risk is known and the manufacturing cycle is well-defined, workers nevertheless risk exposure. More research is needed to optimize the work processes and the protection systems to lower this risk.

  19. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes.

    NARCIS (Netherlands)

    Swainsbury, David J K; Scheidelaar, S.|info:eu-repo/dai/nl/413333418; Foster, Nicolas; Van Grondelle, Rienk; Killian, J.A.|info:eu-repo/dai/nl/071792317; Jones, Michael R.

    2017-01-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such asstyrene maleic acid (SMA) for the solubilisation, purification and

  20. Poly-N-Isopropylacrylamide/acrylic Acid Copolymers for the Generation of Nanostructures at Mica Surfaces and as Hydrophobic Host Systems for the Porin MspA from Mycobacterium smegmatis.

    Science.gov (United States)

    Gamage, Pubudu; Basel, Matthew T; Lovell, Kimberly; Pokhrel, Megh Raj; Battle, Deletria; Ito, Takashi; Pavlenok, Mikhail; Niederweis, Michael; Bossmann, Stefan H

    2009-09-17

    The work presented here aims at utilizing poly-N-isopropyl-acrylamide/acrylic acid copolymers to create nanostructured layers on mica surfaces by a simple spin-casting procedure. The average composition of the copolymers determined by elemental analysis correlates excellently with the feed composition indicating that the radical polymerization process is statistical. The resulting surfaces were characterized by Atomic Force Microscopy (magnetic AC-mode) at the copolymer/air interface. Postpolymerization modification of the acrylic acid functions with perfluoro-octyl-iodide decreased the tendency towards spontaneous formation of nanopores. Crosslinking of individual polymer chains permitted the generation of ultraflat layers, which hosted the mycobacterial channel protein MspA, without compromising its channel function. The comparison of copolymers of very similar chemical composition that have been prepared by living radical polymerization and classic radical polymerization indicated that differences in polydispersity played only a minor role when poly-N-isopropyl-acrylamide/acrylic acid copolymers were spincast, but a major role when copolymers featuring the strongly hydrophobic perfluoro-octyl-labels were used. The mean pore diameters were 23.8+/-4.4 nm for P[(NIPAM)(95.5)-co-(AA)(4.5)] (PDI (polydispersity index)=1.55) and 21.8+/-4.2 nm for P[(NIPAM)(95.3)-co-(AA)(4.7)] (PDI=1.25). The depth of the nanopores was approx. 4 nm. When depositing P[(NIPAM)(95)-co-(AA)(2.8)-AAC(8)F(17 2.2)] (PDI=1.29) on Mica, the resulting mean pore diameter was 35.8+/-7.1 nm, with a depth of only 2 nm.

  1. Multifunctional electroactive electrospun nanofiber structures from water solution blends of PVA/ODA-MMT and poly(maleic acid-alt-acrylic acid): effects of Ag, organoclay, structural rearrangement and NaOH doping factors

    Science.gov (United States)

    Şimşek, Murat; Rzayev, Zakir M. O.; Bunyatova, Ulviya

    2016-06-01

    Novel multifunctional colloidal polymer nanofiber electrolytes were fabricated by green reactive electrospinning nanotechnology from various water solution/dispersed blends of poly (vinyl alcohol-co-vinyl acetate) (PVA)/octadecyl amine-montmorillonite (ODA-MMT) as matrix polymer nanocomposite and poly(maleic acid-alt-acrylic acid) (poly(MAc-alt-AA) and/or its Ag-carrying complex as partner copolymers. Polymer nanofiber electrolytes were characterized using FTIR, XRD, thermal (DSC, TGA-DTG), SEM, and electrical analysis methods. Effects of partner copolymers, organoclay, in situ generated silver nanoparticles (AgNPs), and annealing procedure on physical and chemical properties of polymer composite nanofibers were investigated. The electrical properties (resistance, conductivity, activation energy) of nanofibers with/without NaOH doping agent were also evaluated. This work presented a structural rearrangement of nanofiber mats by annealing via decarboxylation of anhydride units with the formation of new conjugated double bond sites onto partner copolymer main chains. It was also found that the semiconductor behaviors of nanofiber structures were essentially improved with increasing temperature and fraction of partner copolymers as well as presence of organoclay and AgNPs in nanofiber composite.

  2. In situ generation of silver nanoparticles in poly(vinyl alcohol)/poly(acrylic acid) polymer membranes in the absence of reducing agent and their effect on pervaporation of a water/acetic acid mixture

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhard, Shvshankar; Kwon, Yong Sung; Moon, MyungJun; Shon, Min Young [Dept. of Industrial Chemistry, Pukyong National University, Busan (Korea, Republic of); Park, You In; Nam, Seung Eun [Center for membranes, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2016-12-15

    The in situ generation of silver nanoparticles in a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) polymer matrix in the absence of any additional reducing agent is reported and tends to the membrane fabrication using solution-casting. Its effect on the separation of a water/acetic acid mixture by pervaporation is described. The results of UV spectroscopy, scanning electron microscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses showed that the silver nanoparticles were successfully prepared and well dispersed in the polymer matrix. The increased hydrophilicity of the PVA/PAA membrane due to the presence of silver nanoparticles was confirmed by Fourier transform infrared spectroscopy, contact angle measurements, and membrane absorption studies. Pervaporation data for composite membranes showed a three-fold increase in the flux value, while the initially decreased separation factor subsequently showed a constant value. Overall, the pervaporation data suggested that the presence of silver nanoparticles benefited the dehydration process.

  3. Synthesis and characterization of chitosan-graft-poly(acrylic acid)/rice husk ash hydrogels composites; Sintese e caracterizacao de hidrogeis compositos de cinza da casca de arroz e quitosana enxertada com poli(acido acrilico)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Francisco H.A. [Universidade Estadual Vale do Acarau - UVA, Sobral, CE (Brazil); Lopes, Gabriel V.; Pereira, Antonio G.B.; Fajardo, Andre R.; Muniz, Edvani C. [Universidade Estadual de Maringa - UEM, PR (Brazil)

    2011-07-01

    According to environmental concerns, super absorbent hydrogel composites were synthesized based on rice husk ash (RHA), an industrial waste, and Chitosan-graft-poly(acrylic acid). The WAXS and FTIR data confirmed the syntheses of hydrogel composites. The effect of crystalline or amorphous RHA on water uptake was investigated. It was found that the RHA in crystalline form induces higher water capacity (W{sub eq}) of composites hydrogels due to the fact that the intra-interactions among silanol groups on RHA make available new sites in the polymer matrix, which could interact to water. (author)

  4. Pyrolysis of carbonaceous particles and properties of Carbonaceous-g-Poly (acrylic acid-co-acrylamide superabsorbent polymer for agricultural applications

    Directory of Open Access Journals (Sweden)

    Ghazali S.

    2016-01-01

    Full Text Available Utilisation of fertilizer and water are very important in determining the production of agriculture nowadays. The excessive use of fertilizer in plantation somehow could leads to environmental pollution. The present study reported a synthesis of controlled release water retention (CRWR fertilizer coating with superabsorbent polymer (SAPs. Superabsorbent polymer (SAPs are polymers that have ability to absorb and retain large amounts of water relative to their own mass. The presence of coating layer of SAPs on fertilizer granules was believed could reduce excessive used of fertilizer by controlling their dissolution rates and also reduce the environmental pollution. In this study, the effect on the addition of carbonaceous filler in SAPs on the water absorbency was also be compared with control SAPs (without carbonaceous particles. In this study, the carbonaceous filler were obtained from pyrolysis process of empty fruit bunch (EFB biomass. The synthesized of SAPs and carbonaceous-SAPs were carried out via solution polymerization technique by using monomer of poly(acrylic acid (AA, acrylamide (AM, cross linker, methylene bisacrylamide (MBA and initiator, ammonium peroxodisulfate (APS that partially neutralized with sodium hydroxide (NaOH. The CRWR fertilizer was later be prepared by coated the fertilizer granule with SAPs and carbonaceous-SAPs. The water absorbency, morphology and the bonding formation of both CRWR fertilizer were investigated by using tea-beg method, Scanning Electron Microscopy (SEM and Fourier Transform Infrared Spectrophotometer (FTIR, respectively. Moreover, the water retention studies was conducted in order to investigate the efficiency of CRWR coated with SAP and carbonaceous-SAP in retaining the water content in different soil (organic and top soil. Based on the results, the CRWR fertilizer that was coated with carbonaceous-SAP had higher water absorbency value than the CRWR fertilizer without carbonaceous-SAP. Meanwhile

  5. Sheets of branched poly(lactic acid) obtained by one-step reactive extrusion-calendering process: physical aging and fracture behavior

    OpenAIRE

    Cailloux, Jonathan; Santana Pérez, Orlando Onofre; FRANCO URQUIZA, EDGAR ADRIAN; Bou Serra, Jordi; Carrasco Alonso, Félix Ángel; Maspoch Rulduà, Mª Lluïsa

    2014-01-01

    The architectural modifications of a linear poly(D,L-Lactide) acid (PD,L-LA) commercial grade were induced by a one-step reactive extrusion-calendering process using a styrene-glycidyl acrylate copolymer as reactive agent. The melt degradation was counteracted by chain extension and branching reactions, leading to a stabilization of the melt properties and an increase in the molecular weight. For such modified samples [poly(lactic acid) (PLA)-reactive extrusion (REX)], the rate of physical ag...

  6. Survey of volatile substances in kitchen utensils made from acrylonitrile–butadiene–styrene and acrylonitrile–styrene resin in Japan

    National Research Council Canada - National Science Library

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Kawamura, Yoko; Akiyama, Hiroshi

    2014-01-01

    Residual levels of 14 volatile substances, including 1,3‐butadiene, acrylonitrile, benzene, ethylbenzene, and styrene, in 30 kitchen utensils made from acrylonitrile–butadiene–styrene resin ( ABS ) and acrylonitrile–styrene resin...

  7. Lower critical solution temperature behavior of alpha-substituted poly(acrylic acids)s, cyclopolymerization of N-vinylformamido-methylacrylates, and use of the World-Wide Web in polymer science education

    Science.gov (United States)

    Michalovic, Mark Stephen

    A series of alpha-substituted poly(acrylic acid)s was synthesized and characterized. Their aqueous solution properties were investigated with respect to lower critical solution temperature (LCST) behavior. Poly(alpha-methoxymethylacrylic acid) was found to have a lower critical solution temperature (LCST) of 46°C, poly(alpha-methoxyethoxymethylacrylic acid) showed an LCST of 26.5°C and poly(alpha-methoxyethoxyethoxymethylacrylic acid) showed an LCST of 66°C. The cloud points of the solutions of these polymers were found to be sensitive to pH, and to concentrations of additives such as urea, salts, and surfactants. Because of low molecular weight due to chain transfer, high molecular weight analogs of the ether-linked polymers were synthesized in which ester linkages joined the oligo-oxyethylene segment to the acrylate moiety. Poly(alpha-methoxyethoxyacetoxymethylacrylic acid) was the only one of this series to give an LCST with a value of 52.5°C. Copolymers of t-butyl alpha-methoxymethylacrylate (tBMMA) with alpha-(1H,1H- perfluorooctyloxymethyl)acrylic acid (PFOMA) were synthesized, deprotected and their lower critical solution temperatures (LCSTs) evaluated. At PFOMA feed ratios of 0.25 mol % or less, no observable change in the LCST was observed, while at PFOMA feed ratios of above 0.25 mol % to 1.125 mol %, a large linear decrease in the LCST was observed with increasing fluorocarbon content. t-Butyl alpha-(N-vinylformamidomethyl)acrylate (tBVFA) and ethyl alpha-(N-vinylformamidomethyl)acrylate (EVFA) were synthesized from t-butyl alpha-bromomethylacrylate and ethyl alpha-chloromethylacrylate, respectively. tBVFA was found to cyclopolymerize at 120°C in DMF, DMSO, and 1,2-dichlorobenzene at solvent:monomer ratios of 10:1 vol:wt. Molecular weights for poly(tBVFA) ranged from 10,000 to 13,000 as estimated by size-exclusion chromatography. At lower solvent monomer ratio (1:1), and at lower temperature (71°C), crosslinking occurred. EVFA was found to

  8. Functionalized Nanochannels from Self-Assembled and Photomodified Poly(Styrene-b-Butadiene-b-Styrene).

    Science.gov (United States)

    Sutisna, Burhannudin; Polymeropoulos, George; Musteata, Valentina; Sougrat, Rachid; Smilgies, Detlef-M; Peinemann, Klaus-Viktor; Hadjichristidis, Nikolaos; Nunes, Suzana P

    2017-10-04

    Membranes are prepared by self-assembly and casting of 5 and 13 wt% poly(styrene-b-butadiene-b-styrene) (PS-b-PB-b-PS) copolymers solutions in different solvents, followed by immersion in water or ethanol. By controlling the solution-casting gap, porous films of 50 and 1 µm thickness are obtained. A gradient of increasing pore size is generated as the distance from the surface increased. An ordered porous surface layer with continuous nanochannels can be observed. Its formation is investigated, by using time-resolved grazing incident small angle X-ray scattering, electron microscopy, and rheology, suggesting a strong effect of the air-solution interface on the morphology formation. The thin PS-b-PB-b-PS ordered films are modified, by promoting the photolytic addition of thioglycolic acid to the polybutadiene groups, adding chemical functionality and specific transport characteristics on the preformed nanochannels, without sacrificing the membrane morphology. Photomodification increases fivefold the water permeance to around 2 L m(-2) h(-1) bar(-1) , compared to that of the unmodified one. A rejection of 74% is measured for methyl orange in water. The membranes fabrication with tailored nanochannels and chemical functionalities can be demonstrated using relatively lower cost block copolymers. Casting on porous polyacrylonitrile supports makes the membranes even more scalable and competitive in large scale. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Cyanide, carboxyhemoglobin and blood acid-base state in animals exposed to combustion products of various combinations of acrylic fiber and gauze.

    Science.gov (United States)

    Okae, M; Yamamoto, K; Yamamoto, Y; Fukui, Y

    1989-07-01

    In order to examine the usefulness of blood cyanide concentrations as an indicator of whether or not a victim was alive at the start of a fire, blood cyanide concentrations were measured in the bodies that we autopsied in our institute between January 1986 and March, 1987. In the present study, bodies with advanced decomposition were excluded. Thirty-six bodies were included: cyanide as well as carboxyhemoglobin (COHb) were detected in four charred bodies found at the scene of a fire. On the other hand, cyanide was not detected in any of the remaining 30 bodies except in two cases suspected of having ingested a cyanide compound. Rats and rabbits were made to inhale the combustion products of various combinations of acrylic fiber (hydrogen cyanide generating material when heated) and gauze (carbon monoxide generating material when heated). The exposure to the combustion products was continued until death in the rat and until apnea in the rabbit. The concentration of hydrogen cyanide in the exposure chamber and that of blood cyanide, at the time the animal died, correlated with the amount of acrylic fiber heated. In addition to differences in blood COHb and cyanide concentrations, there were also differences in blood gas concentrations between the acrylic fiber and the gauze groups. When the rabbits were switched to room air after the occurrence of apnea, the blood gas value began to normalize.

  10. Acrylic mechanical bond tests

    Energy Technology Data Exchange (ETDEWEB)

    Wouters, J.M.; Doe, P.J.

    1991-02-01

    The tensile strength of bonded acrylic is tested as a function of bond joint thickness. 0.125 in. thick bond joints were found to posses the maximum strength while the acceptable range of joints varied from 0.063 in. to almost 0.25 in. Such joints are used in the Sudbury Neutrino Observatory.

  11. Hyperbranched urethane-acrylates

    Directory of Open Access Journals (Sweden)

    Tasić Srba

    2004-01-01

    Full Text Available The synthesis, characterization and UV-curing of hyperbranched urethaneacrylates (HB-UA were investigated in this study. They were evaluated as oli-gomers in model UV curable coatings. HB-UAs were synthesized by reaction of an aliphatic hyperbranched polyester of the second generation (HBRG2 and an isocyanate adduct, obtained by the reaction of isophoronediisocyana-te and different hydroxy alkyl acrylates. Their thermal properties and viscosities depend on the degree of modification of HBRG2 and the type of hydroxy alkyl acrylate used. The introduction of a flexible alkoxylated spacer between the HBP core and acrylate end groups reduces steric hindrance by moving the cross linkable acrylate groups away from the HBP core and increase its reactivity. Due to the presence of abstractable H-atoms in the α-position to the ether links, HB-UAs based on poly(ethylene oxide monoacrylate are very reactive and do not show oxygen inhibition. The obtained coatings combine a high cross linking density with flexible segments between the cross links, which results in a good compromise between hardness and flexibility and have the potential to be used in different UV-curing applications.

  12. Helbredsrisici ved eksponering for styren i glasfiberplastindustrien

    DEFF Research Database (Denmark)

    Kolstad, Henrik Albert; Ebbehøj, Nielse; Bonde, Jens Peter

    2012-01-01

    This is a summary of the health risks of occupational styrene exposure based on recent reviews. We conclude about the exposure levels that there is strong evidence that styrene causes acute irritation of eyes and respiratory tract above 25 ppm, genotoxic effects above 10 ppm, and persistent nervous...... or relevant exposure levels. We recommend reconsideration of the current Danish threshold limit value of 25 ppm, biological monitoring of styrene exposed workers, and epidemiological analyses of styrene exposure levels and long-term health effects among employees of the Danish reinforced plastics industry....... system effects with for instance reduced psychological performance, colour discrimination and hearing level following long-term styrene exposure above 10 ppm. There is moderate evidence of a causal association with cancer, but data are not sufficient to allow us to pinpoint specific cancers at risk...

  13. Acquired dyschromatopsia among styrene-exposed workers.

    Science.gov (United States)

    Gobba, F; Galassi, C; Imbriani, M; Ghittori, S; Candela, S; Cavalleri, A

    1991-07-01

    We investigated the occurrence of color vision loss in 75 styrene-exposed workers and in 60 referents. Color vision was evaluated by adopting the Lanthony D 15 desaturated panel, a test specifically suited to detect mild acquired dyschromatopsia. The results of the test were expressed as Color Confusion Index. Styrene exposure was evaluated with both environmental and biological monitoring. Airborne levels of the solvent were 3.2 to 549.5 mg/m3. In styrene-exposed workers color vision was significantly impaired when compared with referents matched for age. A significative correlation was found between environmental and urinary levels of styrene and Color Confusion Index excluding the influence of age in multiple regression analysis, indicating the possibility of a dose-effect relationship. The findings suggest that styrene can induce an early appearance of a dose-dependent color vision loss.

  14. Helbredsrisici ved eksponering for styren i glasfiberplastindustrien

    DEFF Research Database (Denmark)

    Kolstad, Henrik Albert; Ebbehøj, Nielse; Bonde, Jens Peter

    2012-01-01

    or relevant exposure levels. We recommend reconsideration of the current Danish threshold limit value of 25 ppm, biological monitoring of styrene exposed workers, and epidemiological analyses of styrene exposure levels and long-term health effects among employees of the Danish reinforced plastics industry.......This is a summary of the health risks of occupational styrene exposure based on recent reviews. We conclude about the exposure levels that there is strong evidence that styrene causes acute irritation of eyes and respiratory tract above 25 ppm, genotoxic effects above 10 ppm, and persistent nervous...... system effects with for instance reduced psychological performance, colour discrimination and hearing level following long-term styrene exposure above 10 ppm. There is moderate evidence of a causal association with cancer, but data are not sufficient to allow us to pinpoint specific cancers at risk...

  15. Measurement of styrene oxide in polystyrenes, estimation of migration to foods, and reaction kinetics and products in food simulants.

    Science.gov (United States)

    Philo, M R; Fordham, P J; Damant, A P; Castle, L

    1997-08-01

    The concentration of styrene-7,8-oxide has been measured in nine base resins and 16 samples of polystyrene articles intended for food contact. The epoxide was not detected in the resins (limit of detection 0.5 mg/kg) but was found in 11 of the 16 packaging samples at up to 2.9 mg/kg. Assuming that the propensity of styrene oxide to migrate is the same as styrene monomer, and using existing survey data for styrene monomer in packaging and foods, the migration levels expected for styrene oxide were calculated. Estimates were from 0.002 to 0.15 microgram/kg styrene oxide in foods. The stability of styrene oxide in the four standard EU food simulants was studied at 40, 100, 150 and 175 degrees C, to establish the transformation products to be expected following migration testing. The half-life at 40 degrees C in distilled water, 15% aqueous ethanol, 3% aqueous acetic acid and olive oil was 15, 23, 2000 hr, respectively. The principal product was the diol from hydrolysis of the epoxide group. Ring opening in aqueous ethanol simulant gave the diol and also the glycol monoethyl ether. It is concluded that this instability of styrene oxide will reduce concentrations in foods, from an already low migration level to even lower levels with the formation of hydrolysis products that are less toxic than the parent epoxide.

  16. Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate

    Energy Technology Data Exchange (ETDEWEB)

    Binder, Thomas [Archer Daniels Midland Company, Decatur, IL (United States); Erpelding, Michael [Archer Daniels Midland Company, Decatur, IL (United States); Schmid, Josef [Archer Daniels Midland Company, Decatur, IL (United States); Chin, Andrew [Archer Daniels Midland Company, Decatur, IL (United States); Sammons, Rhea [Archer Daniels Midland Company, Decatur, IL (United States); Rockafellow, Erin [Archer Daniels Midland Company, Decatur, IL (United States)

    2015-04-10

    Conversion of Lignocellulosic Biomass to Ethanol and Butyl Acrylate. The purpose of Archer Daniels Midlands Integrated Biorefinery (IBR) was to demonstrate a modified acetosolv process on corn stover. It would show the fractionation of crop residue to distinct fractions of cellulose, hemicellulose, and lignin. The cellulose and hemicellulose fractions would be further converted to ethanol as the primary product and a fraction of the sugars would be catalytically converted to acrylic acid, with butyl acrylate the final product. These primary steps have been demonstrated.

  17. A new approach for the immobilization of poly(acrylic) acid as a chemically reactive cross-linker on the surface of poly(lactic) acid-based biomaterials.

    Science.gov (United States)

    Stankevich, Ksenia S; Danilenko, Nadezhda V; Gadirov, Ruslan M; Goreninskii, Semen I; Tverdokhlebov, Sergei I; Filimonov, Victor D

    2017-02-01

    A new approach for the immobilization of poly(acrylic) acid (PAA) as a chemically reactive cross-linker on the surface of poly(lactic) acid-based (PLA) biomaterials is described. The proposed technique includes non-covalent attachment of a PAA layer to the surface of PLA-based biomaterial via biomaterial surface treatment with solvent/non-solvent mixture followed by the entrapment of PAA from its solution. Surface morphology and wettability of the obtained PLA-PAA composite materials were investigated by AFM and the sitting drop method respectively. The amount of the carboxyl groups on the composites surface was determined by using the fluorescent compounds (2-(5-aminobenzo[d]oxazol-2-yl)phenol (ABO) and its acyl derivative N-(2-(2-hydroxyphenyl)benzo[d]oxazol-5-yl)acetamide (AcABO)). It was shown that it is possible to obtain PLA-PAA composites with various surface relief and tunable wettability (57°, 62° and 66°). The capacity of the created PAA layer could be varied from 1.5nmol/cm(2) to 0.1μmol/cm(2) depending on the modification conditions. Additionally, using bovine serum albumin (BSA) it was demonstrated that such composites could be modified with proteins with high binding density (around 0.18nmol/cm(2)). Obtained fluoro-labeled PLA-PAA materials, as well as PLA-PAA composites themselves, are valuable since they can be used for biodegradable polymer implants tracking in living systems and as drug delivery systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Metallic reductant-free synthesis of α-substituted propionic acid derivatives through hydrocarboxylation of alkenes with a formate salt.

    Science.gov (United States)

    Takaya, Jun; Miyama, Ko; Zhu, Chuan; Iwasawa, Nobuharu

    2017-04-04

    A PGeP-pincer palladium-catalyzed hydrocarboxylation of styrenes to obtain pharmaceutically important α-arylpropionic acid derivatives was achieved using a formate salt as both a reductant and a CO 2 source. The reaction was also applicable to vinylsulfone and acrylates. Isotope labeling experiments demonstrated that a CO 2 -recycling mechanism is operative through generation and reaction of a benzylpalladium complex as a carbon nucleophile. This protocol has realized a mild and atom economical CO 2 -fixation reaction without the necessity of using strong metallic reductants.

  19. Study of the mechanical properties of Acrylonitrile Butadiene Styrene - High Impact Polystyrene blends with Styrene Ethylene Butylene Styrene

    OpenAIRE

    PEYDRO Miguel Angel; JUAREZ David; Sanchez-Caballero, Samuel; PARRES Francisco

    2013-01-01

    A binary blend Acrylonitrile Butadiene Styrene ¿ High Impact Polystyrene (ABS-HIPS 50% wt) was prepared on a twin-screw extruder at 190-210 oC. The different mechanical properties were then analyzed using tensile strength and impact tests. The analysis of mechanical properties showed a decrease in elongation at break and impact strength. On the other hand, we have prepared ternary blends of ABS-HIPS- Styrene Ethylene Butylene Styrene (SEBS), varying the percentage of SEBS from 10 to 30 %wt us...

  20. Study of the Influence of adding styrene-ethylene/butadiene-styrene in acrylonitrile-butadiene-styrene and polyethylene blends

    OpenAIRE

    M.A. Peydro; F. Parres; Navarro Vidal, Raúl; Sanchez-Caballero, Samuel

    2014-01-01

    This work studies the recovery of two grades of acrylonitrile butadiene styrene (ABS) contaminated with low-density polyethylene (LDPE), by adding styrene ethylene/butadiene styrene (SEBS). To simulate contaminated ABS, virgin ABS was mixed with 1, 2, 4, and 8% of LDPE and then extruded at 220°C. After this, the ABS with the highest percentage of LDPE (8%) was mixed with 1, 2, 4, and 8% of SEBS and then extruded. Different blends were mechanically, rheologically, optically, and dimensionally ...

  1. Devulcanization of styrene butadiene (SBR) waste tire by controlled oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Rachel R.V.A.; Gontijo, Manuela; Ferraz, Vany P.; Lago, Rochel M.; Araujo, Maria Helena [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: mharaujo@ufmg.br

    2006-05-15

    This work describes the devulcanization of vulcanized SBR (Styrene Butadiene Rubber) based on controlled oxidation with nitric acid. IR, {sup 1}H and {sup 13}C-NMR, CHN elemental analyses, TG, GPC and TPD-MS (Temperature Programmed Decomposition-Mass Spectrometry) experiments suggest that nitric acid promotes two processes: devulcanization by oxidation of the sulfide crosslinks and oxidation of the carbon framework leading to the formation of -COOH and -NO{sub 2} groups. Under aggressive conditions (HNO{sub 3}, reflux) the polymer chain is strongly oxidized and fragmented to a highly oxygenated low molecular weight fraction, which is soluble in water. (author)

  2. Allergic contact dermatitis to artificial fingernails prepared from UV light-cured acrylates.

    Science.gov (United States)

    Hemmer, W; Focke, M; Wantke, F; Götz, M; Jarisch, R

    1996-09-01

    Contact dermatitis from artificial nails made from self-curing acrylic resins is occasionally reported. Recently, UV light-cured products introducing new acrylics have become available. Our purpose was to identify relevant allergens in commercial light-curing products by patch tests and to evaluate the efficacy of "hypoallergenic" products by inclusion into the test series. Patients wearing photobonded acrylic nails who had perionychial and subonychial eczema were patch tested with an acrylate battery and "hypoallergenic" commercial products. Triethyleneglycol dimethacrylate, hydroxyfunctional methacrylates, and (meth)-acrylated urethanes proved to be relevant allergens in photobonded nail preparations. Methacrylated epoxy resin sensitization was not observed. All "hypoallergenic" products provoked positive reactions. The omission of irritant methacrylic acid in UV-curable products does not reduce the high sensitizing potential of new acrylates. In contrast to the manufacturers' declarations, all "hypoallergenic" products continue to include acrylate functional monomers and therefore continue to cause allergic sensitization.

  3. Sheets of branched poly(lactic acid) obtained by one step reactive extrusion calendering process: Melt rheology analysis

    National Research Council Canada - National Science Library

    Cailloux, J; Santana, O. O; Franco-Urquiza, E; Bou, J. J; Carrasco, F; Gamez-Perez, J; Maspoch, M. L

    2013-01-01

    One-step reactive extrusion-calendering process (REX-Calendering) was used in order to obtain sheets of 1mm from two PD,L-LA extrusion grades modified with a styrene-acrylic multifunctional oligomeric agent...

  4. An epidemic of occupational contact dermatitis from an acrylic glue.

    Science.gov (United States)

    Kiec-Swierczynska, Marta; Krecisz, Beata; Swierczynska-Machura, Dominika; Zaremba, Joanna

    2005-03-01

    Dermatological examinations were performed in 81 workers involved in the manufacture of electric coils for television displays, who had worked for 4 years in contact with a glue containing isobornyl acrylate, acrylic acid, N,N dimethyleneacrylamide, phosphine oxide, bis(2,6-dimethoxybenzoyl) (2,4,4-trimethylpentyl)- and beta-carboxyethyl acrylate. The glue was cured by 350-500-nm ultraviolet and visible radiations. Acrylate-specific dermal lesions were detected in 21 (25.9%) people. Occupational irritant contact dermatitis was diagnosed in 12 (15%) of the workers and occupational allergic contact dermatitis in 9 (11.2%). 12 people reacted to acrylates. Cross-reactions with methacrylates were not observed. The highest number of positive tests was obtained with triethyleneglycol diacrylate (10 people) and diethyleneglycol diacrylate (9), followed by 1,6-hexanediol diacrylate (5), 1,4-butanediol diacrylate (4), beta-carboxyethyl acrylate (3), tripropyleneglycol diacrylate (2) and pentaerythritol triacrylate (2). No cases of allergy to isobornyl acrylate, N,N-methylenebisacrylamide or phosphine oxide were noted.

  5. 21 CFR 177.1010 - Acrylic and modified acrylic plastics, semirigid and rigid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylic and modified acrylic plastics, semirigid... Acrylic and modified acrylic plastics, semirigid and rigid. Semirigid and rigid acrylic and modified acrylic plastics may be safely used as articles intended for use in contact with food, in accordance with...

  6. Grafting of styrene onto fluoropolymers films

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, Adriana N.; Zen, Heloisa A.; Parra, Duclerc F.; Lugao, Ademar B.; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente], E-mail: angeral@ipen.br

    2007-07-01

    Grafting of styrene onto poly(vinylidenefluoride) (PVDF) and poly(tetrafluoroethylene) (PTFE) films was studied for the synthesis of ion exchange membranes. Radiation-induced grafting of styrene onto PVDF and PTFE films was investigated by simultaneous method using a Co{sup 60} source. The films of PVDF and PTFE were irradiated at total dose of 20 to 120 kGy and chemical changes were monitored after contact with styrene. Films of PTFE and PVDF were immersed in styrene/toluene 1:1 and were submitted to gamma radiation. After irradiation the samples were evaluated at periods of 0, 7, 14, 21 and 28 days, at room temperature in order to measure the grafting degree. Results of infrared spectroscopic analysis (FTIR), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and the degree of grafting (DOG) were evaluated. The characterization techniques showed that irradiated PVDF and PTFE films exhibited a much higher grafting degree at 120 kGy. (author)

  7. THE USE OF THE FURFURAL FROM THE SOLID WASTE OF SUGAR INDUSTRY (BAGASSE TO SYNTHESIZE -(2-FURYL ACRYLIC ACID AS AN ALTERNATIVE FOR THE RAW MATERIAL OF SUNSCREEN COMPOUND

    Directory of Open Access Journals (Sweden)

    Mitarlis Mitarlis

    2010-06-01

    Full Text Available The research of the usefullness of furfural from bagasse for the production of β-(2-furyl-acrilyc acid as an alternative raw material of sunscreen compound had been done. The research was done on two stages, the first stage was synthesis of furfural from bagasse and the second was synthesis of β-(2-furyl-acrilyc acid that is an analog of cynnamic acid in which some derivatives are known possess activities as sunscreen. Cynnamic acid could be produced from benzaldehyde by Perkin methods using alkali hydrolysis. With the similarity of the main structure, so β-(2-furyl-acrilyc acid can also be synthesized from furfural by Perkin method. The β-(2-furyl-acrilyc acid had been synthesized in this research from furfural isolated from bagasse by NaOH hydrolysis. Synthesis was done by reflux for 2 hr at 140 - 145 oC and 3 hr at 145 - 150 oC. From the spectroscopic data its known that furfural could be produced from bagasse in 11.65 % yield and 33.83% of β-(2-furyl-acrilyc acid from the synthesis on the second process. The UV -Vis spectrophotometer analysis result of β-(2-furyl-acrilyc acids showed λmax at 296.20 nm. It showed that until this step the sunscreen compound can be resulted from furfural isolated from bagasse, especially as a sunscreen that protected skin from eritema (λmax at 290 - 320 nm that is called as sunscreen UV-B. Keywords: Bagasse, furfural, sunscreen, β-(2- furil - acrylic acid.

  8. Study of protein-probe interaction and protective action of surfactant sodium dodecyl sulphate in urea-denatured HSA using charge transfer fluorescence probe methyl ester of N,N-dimethylamino naphthyl acrylic acid.

    Science.gov (United States)

    Mahanta, Subrata; Singh, Rupashree Balia; Guchhait, Nikhil

    2009-03-01

    We have demonstrated that the intramolecular charge transfer (ICT) probe Methyl ester of N,N-dimethylamino naphthyl acrylic acid (MDMANA) serves as an efficient reporter of the proteinous microenvironment of Human Serum Albumin (HSA). This work reports the binding phenomenon of MDMANA with HSA and spectral modulation thereupon. The extent of binding and free energy change for complexation reaction along with efficient fluorescence resonance energy transfer from Trp-214 of HSA to MDMANA indicates strong binding between probe and protein. Fluorescence anisotropy, red edge excitation shift, acrylamide quenching and time resolved measurements corroborate the binding nature of the probe with protein and predicts that the probe molecule is located at the hydrophobic site of the protein HSA. Due to the strong binding ability of MDMANA with HSA, it is successfully utilized for the study of stabilizing action of anionic surfactant Sodium Dodecyl Sulphate to the unfolding and folding of protein with denaturant urea in concentration range 1M to 9M.

  9. FT-IR and FT-Raman studies of cross-linking processes with Ca(2+) ions, glutaraldehyde and microwave radiation for polymer composition of poly(acrylic acid)/sodium salt of carboxymethyl starch--part I.

    Science.gov (United States)

    Grabowska, Beata; Sitarz, Maciej; Olejnik, Ewa; Kaczmarska, Karolina

    2015-01-25

    FT-IR and FT-Raman spectroscopic methods allowed to identify the cross-linking process of the aqueous composition of poly(acrylic acid)/sodium salt of carboxymethyl starch (PAA/CMS-Na) applied as a binder for moulding sands. The cross-linking was performed by chemical methods by introducing cross-linking substances with Ca(2+) ions or glutaraldehyde and by physical way, applying the microwave radiation. It was found that Ca(2+) ions cause formation of cross-linking ionic bonds within carboxyl and carboxylate groups. Glutaraldehyde generates formation of cross-linking bonds with hemiacetal and acetal structures. Whereas in the microwave radiation field, due to dehydration, lattices are formed by anhydride bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. [Treatment of acrylate wastewater by electrocatalytic reduction process].

    Science.gov (United States)

    Yu, Li-Na; Song, Yu-Dong; Zhou, Yue-Xi; Zhu, Shu-Quan; Zheng, Sheng-Zhi; Ll, Si-Min

    2011-10-01

    High-concentration acrylate wastewater was treated by an electrocatalytic reduction process. The effects of the cation exchange membrane (CEM) and cathode materials on acrylate reduction were investigated. It indicated that the acrylate could be reduced to propionate acid efficiently by the electrocatalytic reduction process. The addition of CEM to separator with the cathode and anode could significantly improve current efficiency. The cathode materials had significant effect on the reduction of acrylate. The current efficiency by Pd/Nickel foam, was greater than 90%, while those by nickel foam, the carbon fibers and the stainless steel decreased successively. Toxicity of the wastewater decreased considerably and methane production rate in the biochemical methane potential (BMP) test increased greatly after the electrocatalytic reduction process.

  11. Styrene exposure and biologic monitoring in FRP boat production plants

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, M.; Koizumi, A.; Miyasaka, M.; Watanabe, T.

    1982-02-01

    A survey on styrene exposure was conducted in five small to medium-sized fiber-reinforced plastic (FRP) boat plants utilizing carbon felt dosimeters as personal and stationary samplers to measure 4h (TWA) exposure during workday afternoons. The heaviest exposure, up to 256 ppm by personal sampling and 174 ppm by stationary sampling, took place during the lamination on a mold to produce a boat shell, and the work inside narrow holds also resulted in exposures of a comparable degree. Styrene levels were much lower in other auxiliary works. The TWA of exposure in an entire boat production was estimated to be 40-50 ppm. Installation of several flexible hoses as an exhaust system was proved to be effective in decreasing the vapor concentration. Gas masks were also useful in reducing the exposure. Urine samples were collected from 96 male workers at the end of 8h work (4h in the morning and 4h in the afternoon) and also from 22 nonexposed male subjects, and analyzed for mandelic acid (MA), phenylglyoxylic acid (PhGA), and hippuric acid (HA). When the results of urinalyses were compared with 4-h styrene TWA as monitored by personal sampling, the best correlation was obtained with MA + PhGA/creatinine (the correlation coefficient, 0.88), followed by MA (0.84). For these two cases, regression lines and 95% confidence limits for the group means and for the individual values were calculated. The urinary level of MA, PhGA, and HA in the 22 nonexposed male subjects were also tabulated.

  12. Physical Properties and Biological Activity of Poly(butyl acrylate–styrene) Nanoparticle Emulsions Prepared with Conventional and Polymerizable Surfactants

    Science.gov (United States)

    Garay-Jimenez, Julio C.; Gergeres, Danielle; Young, Ashley; Dickey, Sonja; Lim, Daniel V.; Turos, Edward

    2009-01-01

    Recent efforts in our laboratory have explored the use of polyacrylate nanoparticles in aqueous media as stable emulsions for potential applications in treating drug-resistant bacterial infections. These emulsions are made by emulsion polymerization of acrylated antibiotic compounds in a mixture of butyl acrylate and styrene (7:3 w:w) using sodium dodecyl sulfate (SDS) as a surfactant. Prior work in our group established that the emulsions required purification to remove toxicity associated with extraneous surfactant present in the media. This paper summarizes our investigations of poly(butyl acrylate-styrene) emulsions made using anionic, cationic, zwitterionic, and non-charged (amphiphilic) surfactants, as well as attachable surfactant monomers (surfmers), comparing the cytotoxicity and microbiological activity levels of the emulsion both before and after purification. Our results show that the attachment of a polymerizable surfmer onto the matrix of the nanoparticle neither improves nor diminishes cytotoxic or antibacterial effects of the emulsion, regardless of whether the emulsions are purified or not, and that the optimal properties are associated with the use of the non-ionic surfactants versus those carrying anionic, cationic, or zwitterionic charge. Incorporation of an N-thiolated β-lactam antibacterial agent onto the nanoparticle matrix via covalent attachment endows the emulsion with antibiotic properties against pathogenic bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), without changing the physical properties of the nanoparticles or their emulsions. PMID:19523413

  13. Occupational exposure to styrene in the fibreglass reinforced plastic industry: comparison between two different manufacturing processes.

    Science.gov (United States)

    Tranfo, Giovanna; Gherardi, Monica; Paci, E; Gatto, Mariapia; Gordiani, A; Caporossi, Lidia; Capanna, Silvia; Sisto, Renata; Papaleo, B; Fiumalbi, Carla; Garofani, Patrizia

    2012-01-01

    Styrene is used in manufacturing fiberglass reinforced plastics: and occupational exposure was related to neurotoxicology and genotoxicity. The sum of the metabolites mandelic and phenylglyoxylic acids is the ACGIH biomarker for occupational exposure with a BEI of 400 mg/g of creatinine in end shift urine corresponding to a airborne styrene concentration of 85 mg/m3. There are two main molding processes, open and closed, the last more effective at controlling worker's styrene exposure. To compare the open molding process to the compression of fiber reinforced resin foils, a kind of closed molding, monitoring the styrene exposure of workers in two production sites (A and B). Environmental Monitoring was carried out by Radiello samplers and Biological Monitoring by means of the determination of MA and PGA with HPLC/MS/MS in 10 workers at Site A and 14 at Site B. The median values for styrene exposure resulted 31.1 mg/m3 for Site A and 24.4 mg/m for Site B, while the medians for the sum of the two metabolites in the end shift urine were 86.7 e 33.8 mg/g creatinine respectively. There is a significant linear correlation between personal styrene exposure and the excretion of styrene metabolites (R = 0.74). As expected the exposure markers of the workers of the two production sites resulted higher in the open process. The analytical results of both environmental and biological monitoring were all below the occupational exposure limits, confirming the efficacy of the protective devices.

  14. [Acrylic resin removable partial dentures

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Creugers, N.H.J.

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of

  15. Increased frequency of lymphocyte micronuclei in workers producing reinforced polyester resin with low exposure to styrene

    Energy Technology Data Exchange (ETDEWEB)

    Hoegstedt, B.; Akesson, B.; Axell, K.; Gullberg, B.; Mitelman, F.; Pero, R.W.; Skerfving, S.; Welinder, H.

    1983-06-01

    A new micronucleus method based on the analysis of lymphocytes with preserved cytoplasm revealed an increased frequency of micronuclei in 38 workers employed in a plant producing styrene-modified polyester resin as compared to the frequency in 20 referents (5.9 vs 3.6%). The time-weighted average of the styrene concentration in the workroom air varied between 1 and 36 ppm (mean 13 ppm) during the last year and correlated well to low urinary levels of mandelic acid, which ranged from 9 to 316 mg/g of creatinine (mean 65 mg/g of creatinine).

  16. Ionomeric membranes based on partially sulfonated poly(styrene) : synthesis, proton conduction and methanol permeation

    NARCIS (Netherlands)

    Picchioni, F.; Tricoli, V.; Carretta, N.

    2000-01-01

    Homogeneuosly sulfonated poly(styrene) (SPS) was prepared with various concentration of sulfonic acid groups in the base polymer. Membranes cast from these materials were investigated in relation to proton conductivity and methanol permeability in the temperature range from 20°C to 60°C. It was

  17. Quantum chemistry investigation of secondary reaction kinetics in acrylate-based copolymers.

    Science.gov (United States)

    Cuccato, Danilo; Mavroudakis, Evangelos; Moscatelli, Davide

    2013-05-30

    Recently, a growing amount of attention has been focused on the influence of secondary reactions on the free radical polymerization features and the properties and microstructure of the final polymer, particularly in the context of acrylate copolymers. One of the most challenging aspects of this research is the accurate determination of the corresponding reaction kinetics. In this paper, this problem is addressed using quantum chemistry. The reaction rate coefficients of various backbiting, propagation, and β-scission steps are estimated considering different chain configurations of a terpolymer system composed of methyl acrylate, styrene, and methyl methacrylate. The replacement of methyl acrylate radical units with styrene and methyl methacrylate globally decreases the backbiting probability and shifts the equilibrium toward the reactants, while the effect of replacing adjacent units is weaker and more dependent upon the specific substituting monomer. Propagation kinetics is affected primarily by the replacement of the radical units, while this effect appears to be particularly effective on midchain radical reactivity. The overall results clarify the different physicochemical behavior of chain-end, midchain, and short-branch radicals as a function of copolymer composition, providing new insights into free radical polymerization kinetics.

  18. Properties of Ultra-Violet Cured Poly(diemthylsiloxane)-Urea Acrylates.

    Science.gov (United States)

    1984-11-01

    poly(dimethylsiloxane) material using a mixture of isobornyl acrylate (IBA) and acrylic acid (AA) as a reactive diluent. Unfortunately, the tensile data...RD-fi48 570 PROPERTIES OF ULTRA VIOLET CURED / POLY(DIEMTHYLSILOXANE)-UREA ACRYLATES (U) WISCONSIN UNIV-MADISON DEPT OF CHEMICAL ENGINEERING X YU ET...SwbIffe) S YEo EOT0PRO OE Properties of Ultra-Violet Cured Poly(dimethyl- Interim Technicial Report siloxane)-Urea Acrylates 6. P9011O.11146N ONG, AREPORT1

  19. Advances in acrylic-alkyd hybrid synthesis and characterization

    Science.gov (United States)

    Dziczkowski, Jamie

    2008-10-01

    In situ graft acrylic-alkyd hybrid resins were formed by polymerizing acrylic and acrylic-mixed monomers in the presence of alkyds by introduction of a free radical initiator to promote graft formation. Two-dimensional NMR, specifically gradient heteronuclear multiple quantum coherence (gHMQC), was used to clarify specific graft sites of the hybrid materials. Both individual and mixed-monomer systems were produced to determine any individual monomer preferences and to model current acrylic-alkyd systems. Different classes of initiators were used to determine any initiator effects on graft location. The 2D-NMR results confirm grafting at doubly allylic hydrogens located on the fatty acid chains and the polyol segment of the alkyd backbone. The gHMQC spectra show no evidence of grafting across double bonds on either pendant fatty acid groups or THPA unsaturation sites for any of the monomer or mixed monomer systems. It was also determined that choice of initiator has no effect on graft location. In addition, a design of experiments using response surface methodology was utilized to obtain a better understanding of this commercially available class of materials and relate both the chemical and physical properties to one another. A Box-Behnkin design was used, varying the oil length of the alkyd phase, the degree of unsaturation in the polyester backbone, and acrylic to alkyd ratio. Acrylic-alkyd hybrid resins were reduced with an amine/water mixture. Hydrolytic stability was tested and viscoelastic properties were obtained to determine crosslink density. Cured films were prepared and basic coatings properties were evaluated. It was found that the oil length of the alkyd is the most dominant factor for final coatings properties of the resins. Acrylic to alkyd ratio mainly influences the resin properties such as acid number, average molecular weight, and hydrolytic stability. The degree of unsaturation in the alkyd backbone has minimal effects on resin and film

  20. Waterborne hyperbranched alkyd-acrylic resin obtained by mini emulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Grupo de Investigacion en Materiales Polimericos (GIMAPOL), Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia); Lopez, Betty [Grupo de Investigacion en Ciencia de los Materiales, Universidad de Antioquia, Calle, Medellin (Colombia)

    2016-10-15

    Four waterborne hyper branched alkyd-acrylic resins (HBRAA) were synthesized by mini emulsion polymerization from a hyper branched alkyd resin (HBR), methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA), by using benzoyl peroxide (BPO) and ammonium persulfate (AP) as initiators. The reaction between HBR and acrylic monomers was evidenced by differential scanning calorimetric (DSC), nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The conversion percentage, glass transition temperature (T{sub g}), content of acrylic polymer (determined by soxhlet extraction) and molecular weight increased with the content of acrylic monomers used in the synthesis. The main structure formed during the synthesis was the HBRAA. The analysis by dynamic light scattering (DLS) showed that the particle size distribution of HBRAA2, HBRAA3 and HBRAA4 resins were mainly mono modal. The film properties (gloss, flexibility, adhesion and drying time) of the HBRAA were good. (author)

  1. [Acrylic resin removable partial dentures].

    Science.gov (United States)

    de Baat, C; Witter, D J; Creugers, N H J

    2011-01-01

    An acrylic resin removable partial denture is distinguished from other types of removable partial dentures by an all-acrylic resin base which is, in principle, solely supported by the edentulous regions of the tooth arch and in the maxilla also by the hard palate. When compared to the other types of removable partial dentures, the acrylic resin removable partial denture has 3 favourable aspects: the economic aspect, its aesthetic quality and the ease with which it can be extended and adjusted. Disadvantages are an increased risk of caries developing, gingivitis, periodontal disease, denture stomatitis, alveolar bone reduction, tooth migration, triggering of the gag reflex and damage to the acrylic resin base. Present-day indications are ofa temporary or palliative nature or are motivated by economic factors. Special varieties of the acrylic resin removable partial denture are the spoon denture, the flexible denture fabricated of non-rigid acrylic resin, and the two-piece sectional denture. Furthermore, acrylic resin removable partial dentures can be supplied with clasps or reinforced by fibers or metal wires.

  2. Kinetics and mechanism of styrene epoxidation by chlorite: role of chlorine dioxide.

    Science.gov (United States)

    Leigh, Jessica K; Rajput, Jonathan; Richardson, David E

    2014-07-07

    An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to account for the observed kinetics and product distributions. The model provides an unusually detailed quantitative mechanism for the complex reactions that occur in mixtures of chlorine species and organic substrates, particularly when the strong oxidant chlorite is employed. Kinetic control of the reaction is achieved by the addition of chlorine dioxide to the reaction mixture, thereby eliminating a substantial induction period observed when chlorite is used alone. The epoxidation agent is identified as chlorine dioxide, which is continually formed by the reaction of chlorite with hypochlorous acid that results from ClO produced by the epoxidation reaction. The overall stoichiometry is the result of two competing chain reactions in which the reactive intermediate ClO reacts with either chlorine dioxide or chlorite ion to produce hypochlorous acid and chlorate or chloride, respectively. At high chlorite ion concentrations, HOCl is rapidly eliminated by reaction with chlorite, minimizing side reactions between HOCl and Cl2 with the starting material. Epoxide selectivity (>90% under optimal conditions) is accurately predicted by the kinetic model. The model rate constant for direct reaction of styrene with ClO2(aq) to produce epoxide is (1.16 ± 0.07) × 10(-2) M(-1) s(-1) for 60:40 water/acetonitrile with 0.20 M acetate buffer. Rate constants for para substituted styrenes (R = -SO3(-), -OMe, -Me, -Cl, -H, and -NO2) with ClO2 were determined. The results support the radical addition/elimination mechanism originally proposed by Kolar and Lindgren to account for the formation of styrene oxide in the reaction of styrene with chlorine dioxide.

  3. The potential dermal irritating effect of residual (meth)acrylic monomers in pressure sensitive adhesive tapes.

    Science.gov (United States)

    Tokumura, Fumio; Matsui, Tetsuya; Suzuki, Yasuko; Sado, Masashi; Taniguchi, Masaharu; Kobayashi, Ichiro; Kamiyama, Masashi; Suda, Shin; Nakamura, Atsushi; Yamazaki, Yuhiro; Yamori, Akira; Igarashi, Ryosuke; Kawai, Jun; Oka, Keiji

    2010-01-01

    It is generally thought that residual unpolymerized (meth)acrylic monomers commonly found in pressure sensitive adhesive tapes for medical use may cause dermal irritation, but a systematic study has never been carried out. Therefore, we assessed the potential dermal irritating effect of residual (meth)acrylic monomers. We studied seven acrylic monomers, acrylic acid (AA), methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (n-BA), n-hexyl acrylate (n-HA), 2-ethylhexyl acrylate (2-EHA) and 2-hydroxyethyl acrylate (HEA), as well as three methacrylic monomers, methacrylic acid (MAA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (2-HEMA). We first examined their cytotoxic effect on a cultured dermis model using the MTT method to determine their EC(50) and then performed a primary irritation test in rabbits using the monomers at three different concentrations (i.e., EC(50) , one-tenth EC(50) and 10 times EC(50)). Marked variations were found in cytotoxic and dermal irritating activities among the (meth)acrylic monomers tested. HEA exhibited the most potent dermal irritation having the lowest erythema dose (the concentration which gives a primary dermal irritation index of 1.00) of 460 ppm. But the other monomers exhibited less potent dermal irritation (lowest erythema doses > or =1000 ppm). For the monomers, significant correlation was found between cytotoxic activity and in vivo dermal irritating activity. Our results show that residual unpolymerized (meth)acrylic monomers in adhesive tapes are unlikely to induce skin irritation except for HEA. This study also suggests that cultured skin models are extremely useful as a screening method for chemical substances that could potentially cause dermal irritating activity.

  4. 21 CFR 177.1810 - Styrene block polymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The styrene...

  5. Cross-sensitization patterns in acrylate allergies.

    Science.gov (United States)

    Jordan, W P

    1975-01-01

    Five subjects developed allergic contact dermatitis to one or more acrylate components used in a commercial adhesive tape. Patch testing to acrylic monomers was performed to examine their cross-reaction patterns. Two subjects with broad cross-reactions to acrylates did not react to methyl methacrylate or the alkyl methacrylate that corresponded to the acrylate which induced the sensitization. Methyl methacrylate may not be adequate as a screen for many acrylates used commercially.

  6. Survey of volatile substances in kitchen utensils made from acrylonitrile–butadiene–styrene and acrylonitrile–styrene resin in Japan

    OpenAIRE

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Kawamura, Yoko; Akiyama, Hiroshi

    2014-01-01

    Residual levels of 14 volatile substances, including 1,3-butadiene, acrylonitrile, benzene, ethylbenzene, and styrene, in 30 kitchen utensils made from acrylonitrile–butadiene–styrene resin (ABS) and acrylonitrile–styrene resin (AS) such as slicers, picks, cups, and lunch boxes in Japan were simultaneously determined using headspace gas chromatography/mass spectroscopy (HS-GC/MS). The maximum residual levels in the ABS and AS samples were found to be 2000 and 2800 μg/g of styrene, respectivel...

  7. Synthesis of Radiation Curable Palm Oil–Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations

    Directory of Open Access Journals (Sweden)

    Ashraf M. Salih

    2015-08-01

    Full Text Available Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA from an epoxidized palm oil product (EPOP as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  8. Synthesis of Radiation Curable Palm Oil-Based Epoxy Acrylate: NMR and FTIR Spectroscopic Investigations.

    Science.gov (United States)

    Salih, Ashraf M; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md Zin Wan

    2015-08-04

    Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.

  9. Two decades of occupational (meth)acrylate patch test results and focus on isobornyl acrylate

    NARCIS (Netherlands)

    Christoffers, Wietske A; Coenraads, Pieter Jan; Schuttelaar, Marie-Louise A

    BACKGROUND: Acrylates constitute an important cause of occupational contact dermatitis. Isobornyl acrylate sensitization has been reported in only 2 cases. We encountered an industrial process operator with occupational contact dermatitis caused by isobornyl acrylate. OBJECTIVES: (i) To investigate

  10. Two decades of occupational (meth)acrylate patch test results and focus on isobornyl acrylate

    OpenAIRE

    Christoffers, Wietske A; Coenraads, Pieter Jan; Schuttelaar, Marie-Louise A

    2013-01-01

    BACKGROUND: Acrylates constitute an important cause of occupational contact dermatitis. Isobornyl acrylate sensitization has been reported in only 2 cases. We encountered an industrial process operator with occupational contact dermatitis caused by isobornyl acrylate. OBJECTIVES: (i) To investigate whether it is relevant to add isobornyl acrylate to the (meth)acrylate test series. (ii) To report patients with (meth)acrylate contact allergy at an occupational dermatology clinic. PATIENTS/MATER...

  11. Catalytic dehydrogenations of ethylbenzene to styrene

    NARCIS (Netherlands)

    Kapteijn, F.; Makkee, M.; Nederlof, C.

    This research work on the catalytic dehydrogenation of ethylbenzene (EB) to styrene (ST) had a primary goal of developing improved catalysts for dehydrogenation processes both in CO2 as well as with O2 that can compete with the conventional dehydrogenation process in steam. In order to achieve this

  12. Graft Copolymerization and Characterization of Styrene with ...

    African Journals Online (AJOL)

    MBI

    2017-05-24

    May 24, 2017 ... 1Department of Chemistry, Faculty of Science, Northwest University, P.M.B 3220, Kano, Nigeria. 2Department of Pure and ... In this study, styrene was successfully grafted onto chitosan by conventional free radical polymerization technique, using ..... radical species is very high, chain transfer and reaction ...

  13. SYNTHESIS OF ACRYLIC ESTERS IN PTC: KINETICS AND ECOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    G.Torosyan

    2013-06-01

    Full Text Available The synthesis of esters of acrylic acids, which are applied for synthesis of polymeric materials by phase transfer catalysis were discussed (PTC, which is very useful for reduction of reaction consumption of materials and power.This method has substantial advantages including high speed of the process, soft condition of reaction and reduced pollution.

  14. Performance of waterborne acrylic surface coatings on wood ...

    Indian Academy of Sciences (India)

    Two waterborne acrylic coatings were applied on spruce wood, impregnated with two copperethanolamine containing preservatives (CuE and CuEQ), one of them (CuEQ) containing a boron compound, octanoic acid and a quaternary ammonium compound as additives. Lower contact angles and deeper penetration of both ...

  15. Preparation and swelling properties of pH-sensitive composite hydrogel beads based on chitosan-g-poly (acrylic acid)/vermiculite and sodium alginate for diclofenac controlled release.

    Science.gov (United States)

    Wang, Qin; Xie, Xiaoling; Zhang, Xiaowei; Zhang, Junping; Wang, Aiqin

    2010-04-01

    A series of pH-sensitive composite hydrogel beads, chitosan-g-poly (acrylic acid)/vermiculite/sodium alginate (CTS-g-PAA/VMT/SA), was prepared using CTS-g-PAA/VMT composite and SA by Ca(2+) as the crosslinking agent. The structure and morphologies of the developed composite hydrogel beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling properties and pH-sensitivity of the beads were investigated. In addition, the drug loading and controlled release behaviors of the beads were also evaluated using diclofenac sodium (DS) as the model drug in stimulated gastric fluids (pH 2.1) and intestinal fluids (pH 6.8). The results indicate that the composite hydrogel beads showed good pH-sensitivity. The release rate of the drug from the composite hydrogel beads is remarkably slowed down, which indicated that incorporating VMT into the composite hydrogel beads can improve the burst release effect of the drug. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Cyto- and genotoxicological assessment and functional characterization of N-vinyl-2-pyrrolidone-acrylic acid-based copolymeric hydrogels with potential for future use in wound healing applications

    Energy Technology Data Exchange (ETDEWEB)

    Kirf, Dominik; Devery, Sinead M [Department of Life and Physical Science, Athlone Institute of Technology (Ireland); Higginbotham, Clement L [Materials Research Institute, Athlone Institute of Technology (Ireland); Rowan, Neil J, E-mail: sdevery@ait.i, E-mail: dkirf@ait.i, E-mail: chigginbotham@ait.i, E-mail: nrowan@ait.i [Department of Nursing and Health Science, Athlone Institute of Technology (Ireland)

    2010-06-01

    This study investigated the toxicity of N-vinyl-2-pyrrolidone-acrylic acid copolymer hydrogels crosslinked with ethylene glycol dimethacrylate or poly(ethylene glycol) dimethacrylate. There is a pressing need to establish the toxicity status of these new copolymers because they may find applications in future wound healing processes. Investigations revealed that the capacity of these hydrogels for swelling permitted the retention of high amounts of water yet still maintaining structural integrity. Reverse phase HPLC analysis suggested that unreacted monomeric base material was efficiently removed post-polymerization by applying an additional purification process. Subsequently, in vitro toxicity testing was performed utilizing direct and indirect contact exposure of the polymers to human keratinocytes (HaCaT) and human hepatoma (HepG2) cells. No indication of significant cell death was observed using the established MTT, neutral red (NR) and fluorescence-based toxicity endpoint indicators. In addition, the alkaline Comet assay showed no genotoxic effects following cell exposure to hydrogel extracts. Investigations at the nucleotide level using the Ames mutagenicity assay demonstrated no evidence of mutagenic activity associated with the polymers. Findings from this study demonstrated that these hydrogels are non-cytotoxic and further work can be carried out to investigate their potential as a wound-healing device that will impact positively on patient health and well-being.

  17. Preparation of Uniform-Sized and Dual Stimuli-Responsive Microspheres of Poly(N-Isopropylacrylamide/Poly(Acrylic acid with Semi-IPN Structure by One-Step Method

    Directory of Open Access Journals (Sweden)

    En-Ping Lai

    2016-03-01

    Full Text Available A novel strategy was developed to synthesize uniform semi-interpenetrating polymer network (semi-IPN microspheres by premix membrane emulsification combined with one-step polymerization. Synthesized poly(acrylic acid (PAAc polymer chains were added prior to the inner water phase, which contained N-isopropylacrylamide (NIPAM monomer, N,N′-methylene bisacrylamide (MBA cross-linker, and ammonium persulfate (APS initiator. The mixtures were pressed through a microporous membrane to form a uniform water-in-oil emulsion. By crosslinking the NIPAM in a PAAc-containing solution, microspheres with temperature- and pH-responsive properties were fabricated. The semi-IPN structure and morphology of the microspheres were confirmed by Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The average diameter of the obtained microspheres was approximately 6.5 μm, with Span values of less than 1. Stimuli-responsive behaviors of the microspheres were studied by the cloud-point method. The results demonstrated that semi-IPN microspheres could respond independently to both pH and temperature changes. After storing in a PBS solution (pH 7.0 at 4 °C for 6 months, the semi-IPN microspheres remained stable without a change in morphology or particle size. This study demonstrated a promising method for controlling the synthesis of semi-IPN structure microspheres with a uniform size and multiple functionalities.

  18. (Liquid + liquid) equilibria in {l_brace}water + acrylic acid + (1-butanol, or 2-butanol, or 1-pentanol){r_brace} systems at T = 293.2 K, T = 303.2 K, and T = 313.2 K and atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Batistell, Melissa C.; Alves, Thiago C.; Guadagnini, Talita R.; Hadlich de Oliveira, Leonardo [School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas-SP (Brazil); Aznar, Martin, E-mail: maznar@feq.unicamp.br [School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas-SP (Brazil)

    2011-09-15

    Highlights: > Acrylic acid solubilizes preferably in the studied solvents than in water. > Immiscibility region increases in the order: 2-butanol < 1-butanol < 1-pentanol. > Immiscibility region reduces little with an increase in temperature. > K and S values show that 1-pentanol is the best studied solvent. - Abstract: (Liquid + liquid) equilibrium (LLE) data for {l_brace}water + acrylic acid + (1-butanol, or 2-butanol, or 1-pentanol){r_brace} at T = 293.2 K, T = 303.2 K, and T = 313.2 K and atmospheric pressure ({approx}95 kPa) were determined by Karl Fischer titration and densimetry. All systems present type I binodal curves. The size of immiscibility region changes little with an increase in temperature, but increases according to the solvent, following the order: 2-butanol < 1-butanol < 1-pentanol. Values of solute distribution and solvent selectivities show that 1-pentanol is a better solvent than 1-butanol or 2-butanol for acrylic acid removal from water solutions. Quality of data was ascertain by Hand and Othmer-Tobias equations, giving R{sup 2} > 0.916, mass balance and accordance between tie lines and cloud points. The NRTL model was used to correlate experimental data, by estimating new energy parameters, with root mean square deviations below 0.0053 for all systems.

  19. A novel method for recovery of acidic sludge of used-motor oil reprocessing industries to bitumen using bentonite and SBS

    National Research Council Canada - National Science Library

    Ahmad Jonidi Jafari; malek hassanpour; Mitra Gholam; Mehdi Farzadkia

    2014-01-01

    .... The acidic sludge contains unsaturated compounds that are polar and asphaltene. The bitumen under certain conditions is produced from mixing of bentonite, polymer styrene – butadiene – styrene (SBS), and acidic sludge...

  20. Lactate and acrylate metabolism by Megasphaera elsdenii under batch and steady-state conditions.

    Science.gov (United States)

    Prabhu, Rupal; Altman, Elliot; Eiteman, Mark A

    2012-12-01

    The growth of Megasphaera elsdenii on lactate with acrylate and acrylate analogues was studied under batch and steady-state conditions. Under batch conditions, lactate was converted to acetate and propionate, and acrylate was converted into propionate. Acrylate analogues 2-methyl propenoate and 3-butenoate containing a terminal double bond were similarly converted into their respective saturated acids (isobutyrate and butyrate), while crotonate and lactate analogues 3-hydroxybutyrate and (R)-2-hydroxybutyrate were not metabolized. Under carbon-limited steady-state conditions, lactate was converted to acetate and butyrate with no propionate formed. As the acrylate concentration in the feed was increased, butyrate and hydrogen formation decreased and propionate was increasingly generated, while the calculated ATP yield was unchanged. M. elsdenii metabolism differs substantially under batch and steady-state conditions. The results support the conclusion that propionate is not formed during lactate-limited steady-state growth because of the absence of this substrate to drive the formation of lactyl coenzyme A (CoA) via propionyl-CoA transferase. Acrylate and acrylate analogues are reduced under both batch and steady-state growth conditions after first being converted to thioesters via propionyl-CoA transferase. Our findings demonstrate the central role that CoA transferase activity plays in the utilization of acids by M. elsdenii and allows us to propose a modified acrylate pathway for M. elsdenii.

  1. Preparation and Characterization of Acrylic Primer for Concrete Substrate Application

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2016-01-01

    Full Text Available This study dealt with the properties of acrylic primer for concrete substrate using acrylic syrup, made from a methyl methacrylate monomer solution of terpolymers. Terpolymer systems consisting of methyl methacrylate (MMA, 2-ethylhexyl acrylate (2-EHA, and methacrylic acid (MAA with different chemical composition ratios of MMA and 2-EHA were synthesized through bulk polymerization using azobisisobutyronitrile (AIBN as initiator. The terpolymer composition is characterized by FTIR, 1H NMR, DSC, TGA, and SEM. The glass transition temperature and the thermal stability increased with increasing amounts of MMA in the terpolymer backbone. The effect of chemical composition of terpolymers on physicomechanical properties of primer films was investigated. However, increasing the amount of MMA in terpolymer backbone increased tensile and contact angle of primer films while elongation at break, water absorption, and bond strength are decreased. In particular, the primer syrup containing 65% 2-EHA has good bonding strength with concrete substrate around 1.1 MPa.

  2. Styrene revisited--exposure assessment and risk estimation in reinforced plastics industry

    Energy Technology Data Exchange (ETDEWEB)

    Sorsa, M.; Anttila, A.; Jaerventaus, H.K.; Kubiak, R.; Norppa, H.; Nylander, L.; Pekari, K.; Pfaeffli, P.V.; Vainio, H. (Institute of Occupational Health, Department of Industrial Hygiene and Toxicology, Helsinki (Finland))

    1991-01-01

    A survey performed in 32 workshops in reinforced plastics industry showed the mean TWA 8 h concentration of styrene in personal air to be 43 ppm (range 5-182 ppm) among laminators and 11 ppm (range 1-133 ppm) among other workers. The biological measurement of urinary mandelic acid + phenylglyoxylic acid showed mean values of 2.4 mmol/l among laminators without respirators and 1.3 mmol/l when respirators were used. No effects of work related exposure were detected in the cytogenetic parameters, chromosome aberrations, sister chromatid exchanges or micronuclei analyzed in peripheral blood lymphocytes. Grading of the exposure on the basis of lamination method, years of exposure, daily laminating time, air styrene concentration and urinary mandelic acid among laminators, neither revealed any dose dependency.

  3. Study of the thermal properties of Acrylonitrile Butadiene Styrene - High Impact Polystyrene blends with Styrene Ethylene Butylene Styrene

    OpenAIRE

    PEYDRO Miguel Angel; JUAREZ David; Sanchez-Caballero, Samuel; PARRES Francisco

    2013-01-01

    A binary blend Acrylonitrile Butadiene Styrene ¿ High Impact Polystyrene (ABS-HIPS 50% wt) was prepared on a twin-screw extruder at 190-210 oC. The different properties were then analyzed using melt flow index (MFI), thermogravimetric analysis (TGA), and Fourier Transform Infrared spectroscopy (FTIR). FTIR analysis indicated heterogeneous distribution of the blend in injected pieces and SEM micrographs show heterogeneous distribution of both phase (ABS and HIPS). On the other hand, we have pr...

  4. Dual stimuli-responsive Fe3O4 graft poly(acrylic acid-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate copolymer micromicelles: surface RAFT synthesis, self-assembly and drug release applications

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2017-10-01

    Full Text Available Abstract Background Stimuli-responsive polymer materials are a new kind of intelligent materials based on the concept of bionics, which exhibits more significant changes in physicochemical properties upon triggered by tiny environment stimuli, hence providing a good carrier platform for antitumor drug delivery. Results Dual stimuli-responsive Fe3O4 graft poly(acrylic acid-block-poly(2-methacryloyloxyethyl ferrocenecarboxylate block copolymers (Fe3O4-g-PAA-b-PMAEFC were engineered and synthesized through a two-step sequential reversible addition-fragmentation chain transfer polymerization route. The characterization was performed by FTIR, 1H NMR, SEC, XRD and TGA techniques. The self-assembly behavior in aqueous solution upon triggered by pH, magnetic and redox stimuli was investigated via zeta potentials, vibration sample magnetometer, cyclic voltammetry, fluorescent spectrometry, dynamic light scattering, XPS, TEM and SEM measurements. The experimental results indicated that the Fe3O4-g-PAA-b-PMAEFC copolymer materials could spontaneously assemble into hybrid magnetic copolymer micromicelles with core–shell structure, and exhibited superparamagnetism, redox and pH stimuli-responsive features. The hybrid copolymer micromicelles were stable and nontoxic, and could entrap hydrophobic anticancer drug, which was in turn swiftly and effectively delivered from the drug-loaded micromicelles at special microenvironments such as acidic pH and high reactive oxygen species. Conclusion This class of stimuli-responsive copolymer materials is expected to find wide applications in medical science and biology, etc., especially in drug delivery system.

  5. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    LENUS (Irish Health Repository)

    Nagle, Susan

    2009-09-01

    This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and\\/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength.

  6. Kinetics and mechanism of polymer dispersion formation on based of (meth)acrylates. Part 2

    OpenAIRE

    GOLDFEIN M.D.; KOZHEVNIKOV N.V.; KOZHEVNIKOVA N.I.; ZAIKOV G.E.

    2015-01-01

    The aim of the present work was to establish the kinetics and mechanism of joint emulsion polymerization of methyl acrylate with metacrylic acid (MAA) or acrylonitrile, which underlies production of many commercial acrylic polymeric dispersions. The emulsion polymerization of methyl methacrylate (MMA) and copolymers with acrylonitrile (AN) and methacrylic acid (MAA) was studied. Also some aspects of kinetics and mechanism of polymeric latexes formation processes in absence of emulsifier were ...

  7. Molecular analysis on the utilization of oil palm empty fruit bunches fiber as reinforcement for acrylonitrile butadiene styrene biocomposites

    Science.gov (United States)

    Hermawan, B.; Nikmatin, S.; Alatas, H.; Sudaryanto; Sukaryo, S. G.

    2017-05-01

    Oil palm empty fruit bunches (OPEFB) was one of the solid waste produced by the palm oil factory and were totally plentiful in biomass. OPEFB fiber used as reinforcement of polymer matrix acrylonitrile butadiene styrene (ABS). The use of FTIR is to see that there is no changes in the molecules of the constituent biocomposite ABS and OPEFB. The reactivity of butadiene and styrene through the double bond- π conjugated system, contributed to the bond reaction with the maleic acid as compatibilizer witch is grafted to the system. It is concluded that the posible grafting reaction occurs by the addition of the MAH to the double bond of the butadiene and styrene. The hydroxyl group of cellulose can interact with this maleic acid to form a bond through the carboxyl group.

  8. Expanding Upon Styrene Biosynthesis to Engineer a Novel Route to 2-Phenylethanol.

    Science.gov (United States)

    Machas, Michael S; McKenna, Rebekah; Nielsen, David R

    2017-10-01

    2-Phenylethanol (2PE) is a key molecule used in the fragrance and food industries, as well as a potential biofuel. In contrast to its extraction from plant biomass and/or more common chemical synthesis, microbial 2PE production has been demonstrated via both native and heterologous expression of the yeast Ehrlich pathway. Here, a novel alternative to this established pathway is systematically engineered in Escherichia coli and evaluated as a more robust and efficient route. This novel pathway is constructed via the modular extension of a previously engineered styrene biosynthesis pathway, proceeding from endogenous l-phenylalanine in five steps and involving four heterologous enzymes. This "styrene-derived" pathway boasts nearly a 10-fold greater thermodynamic driving force than the Ehrlich pathway, and enables reduced accumulation of acetate byproduct. When directly compared using a host strain engineered for l-phenylalanine over-production, preservation of phosphoenolpyruvate, and reduced formation of byproduct 2-phenylacetic acid, final 2PE titers via the styrene-derived and Ehrlich pathways reached 1817 and 1164 mg L-1 , respectively, at yields of 60.6 and 38.8 mg g-1 . Following optimization of induction timing and initial glucose loading, 2PE titers by the styrene-derived pathway approached 2 g L-1 - nearly a two-fold twofold increase over prior reports for 2PE production by E. coli employing the Ehrlich pathway. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Prognosis and determination of the threshold of chronic effect of carbon disulfide and styrene

    Energy Technology Data Exchange (ETDEWEB)

    Popov, T.; Zaprianov, Z.; Benchev, I.; Spasovski, M.

    1982-01-01

    Two series of studies were carried out: I--in workers exposed to four different mean annual CS/sub 2/ concentrations(6 mg/m3m3; 12 mg/m3; 51 mg/m3 and 247 mg/m3 and II series) in workers exposed to three styrene concentrations-(-I mg/m3; 40 mg/m3 and 400 mg/m3). The results obtained in series I show the role of the primary toxic effect (inhibition of oxidases with mixed function) and of the adaptation reactions to it with a view to accurate specifying the threshold of chronic CS/sub 2/ effect. The mathematical expression of the correlation between styrene concentration in air and blood, of phenyl-glyoxylic and mandelic acid in the urine of the exposed subjects enables the prognosis that the threshold of the noxious styrene effect is within the range of 150 mg/m3 to 250 mg/m3. A reduction on CS/sub 2/ MAC is proposed-(-from 10 mg/m3 to I mg/m3) and the correction of styrene MAC-(-from 5 mg/m3 to 30-50 mg/m3).

  10. Reduction of ethylenediaminetetraacetic acid iron(III) by Klebsiella sp. FD-3 immobilized on iron(II, III) oxide poly (styrene-glycidyl methacrylate) magnetic porous microspheres: effects of inorganic compounds and kinetic study of effective diffusion in porous media.

    Science.gov (United States)

    Zhou, Zuo-Ming; Wang, Xiao-Yan; Lin, Tian-Ming; Jing, Guo-Hua

    2014-11-01

    Fe3O4 poly (styrene-glycidyl methacrylate) magnetic porous microspheres (MPPMs) were introduced to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium applied to reduce Fe(III)EDTA. The effects of potential inhibitors (S(2-), SO3(2-), NO3(-), NO2(-) and Fe(II)EDTA-NO) on Fe(III)EDTA reduction were investigated. S(2-) reacted with Fe(III)EDTA as an electron-shuttling compound and enhanced the reduction. But Fe(III)EDTA reduction was inhibited by SO3(2-) and Fe(II)EDTA-NO due to their toxic to microorganisms. Low concentrations of NO3(-) and NO2(-) accelerated Fe(III)EDTA reduction, but high concentrations inhibited the reduction, whether by free or immobilized FD-3. The immobilized FD-3 performed better than freely-suspended style. The substrate mass transfer and diffusion kinetics in the porous microspheres were calculated. The value of Thiele modulus and effectiveness factors showed that the intraparticle diffusion was fairly small and neglected in this carrier. Fe(III)EDTA reduction fitted first-order model at low Fe(III)EDTA concentration, and changed to zero-order model at high concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Interacting Blends of Novel Unsaturated Polyester Amide Resin with Styrene

    Directory of Open Access Journals (Sweden)

    Hasmukh S. Patel

    2004-01-01

    Full Text Available Novel unsaturated poly (ester-amide resins (UPEAs were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA and unsaturated aliphatic bisamic acids using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, Styrene (STY. to produce a homogeneous resin syrup. The curing of these UPEAs-STY. resin blends was carried out by using benzoyl peroxide (BPO as a catalyst and was monitored by using a differential scanning calorimeter (DSC. The glass fibre reinforced composites (i.e. laminates of these UPEA-STY. resin blends were fabricated using the DSC data. The chemical, mechanical and electrical properties of the glass fibre composites have also been evaluated. The unreinforced cured samples of the UPEA-STY. resin blends were also analyzed by thermogravimetry (TGA.

  12. 40 CFR 721.2805 - Acrylate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under this...

  13. Isobornyl acrylate contact allergy: Rare or underdiagnosed?

    NARCIS (Netherlands)

    Christoffers, W.A.; Coenraads, P.J.; Schuttelaar, M.L.A.

    2012-01-01

    Background: Allergic contact dermatitis to isobornyl acrylate has been reported in only two cases in literature. Therefore, isobornyl acrylate is not part of a (meth) acrylates patch test series. At our department an industrial worker presented with therapy-resistant hand eczema and sensitizations

  14. Radiation grafting of styrene onto polypropylene fibres by a 10 MeV electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Vahdat, A. [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Bahrami, Hajir [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)]. E-mail: hajirb@aut.ac.ir; Ansari, N. [Textile Engineering Department, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ziaie, F. [Yazd Radiation Processing Centre, Yazd (Iran, Islamic Republic of)

    2007-05-15

    The radiation-induced graft copolymerization is an effective method for modification of the chemical and physical properties of polypropylene. Graft copolymerization of styrene onto polypropylene fibers has been studied by simultaneous irradiation method, using a 10 MeV electron beam. Samples were irradiated in an environment of nitrogen gas. The effects of radiation dose and styrene concentration in methanol, on the grafting yield were investigated. The effects of polyfunctional monomer, i.e., trimethylopropane trimethacrylate (TMPTMA) and acid (sulfuric acid) on the grafting yield were also examined. The grafted samples were then sulfonated and allowed to react with solution of a basic dye. The samples were characterized by mechanical properties and thermal stability. The mechanical properties of the radiated samples were reduced and the grafted samples had lower mechanical properties.

  15. Evaluation of the antifouling and photocatalytic properties of poly(vinylidene fluoride) plasma-grafted poly(acrylic acid) membrane with self-assembled TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    You, Sheng-Jie, E-mail: sjyou@cycu.edu.tw [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Semblante, Galilee Uy [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Lu, Shao-Chung [Department of Civil Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); Damodar, Rahul A. [Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chungli, Taiwan (China); R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Wei, Ta-Chin [R and D Center for Membrane Technology, Chung Yuan Christian University, Chungli, Taiwan (China); Department of Chemical Engineering, Chung Yuan Christian University, Chungli, Taiwan (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Plasma and grafting parameters that maximized TiO{sub 2} binding sites were found. Black-Right-Pointing-Pointer PVDF hydrophilicity was vastly improved compared to other modification techniques. Black-Right-Pointing-Pointer At least 1.5% TiO{sub 2} and 30 min UV exposure were needed to attain full flux recovery. Black-Right-Pointing-Pointer Photocatalytic membranes could remove up to 42% of 50 mg/l RB5 dye. - Abstract: Immobilization of TiO{sub 2} is a promising approach that produces antifouling and photocatalytic membranes that could help advance wastewater treatment and re-use processes. In this study, poly(acrylic acid) (PAA) was plasma-grafted on commercial poly(vinylidene fluoride) (PVDF) to introduce functional groups on the membrane surface that can support the nanoparticles. It was found that plasma treatment at 100 W for 120 s followed by liquid grafting with 70% aqueous AA at 60 Degree-Sign C for 2 h maximized the number of TiO{sub 2} binding sites. Membrane hydrophilicity was tremendously enhanced by the self-assembly of TiO{sub 2}, following a direct proportionality to TiO{sub 2} loading. The membrane with 0.5% TiO{sub 2} loading maintained the highest pure water flux and the best protein antifouling property. UV irradiation triggered the photodegradation of strongly bound foulants, but at least 1.5% TiO{sub 2} and 30 min cumulative irradiation were necessary to completely recover the membrane's original performance. The TiO{sub 2}-modified membranes removed 30-42% of 50 mg/l aqueous Reactive Black 5 (RB5) dye. The fabricated membranes demonstrate huge potential for use in membrane reactors with high hydrophilicity, fouling mitigation, and photocatalytic capability.

  16. Technology and the use of acrylics for provisional dentine protection.

    Science.gov (United States)

    Kapusevska, Biljana; Dereban, Nikola; Popovska, Mirjana; Nikolovska, Julijana; Radojkova Nikolovska, Vеrа; Zabokova Bilbilova, Efka; Mijoska, Aneta

    2013-01-01

    Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue.

  17. Styrene polymerization in three-component cationic microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Luna, V.H.; Puig, J.E. (Universidad de Guadalajara (Mexico)); Castano, V.M. (Instituto de Fisica (Mexico)); Rodriguez, B.E.; Murthy, A.K.; Kaler, E.W. (Univ. of Delaware, Newark (USA))

    1990-06-01

    The polymerization of styrene in three-component dodecyltrimethylammonium bromide (DTAB) microemulsions is reported. The structure of the unpolymerized microemulsions, determined by conductimetry and quasielastic light scattering (QLS), is consistent with styrene-swollen micelles in equilibrium with regular micelles, both dispersed in an aqueous phase. Polymerization of these transparent microemulsions, monitored by QLS an dilatometry, produced stable, bluish monodisperse microlatices with particle radii ranging from 20 to 30 nm, depending on styrene content. Polymerization initiation appears to occur in the styrene-swollen micelles, and the polymer particles grow by recruiting monomer and surfactant from uninitiated droplets and small micelles.

  18. Genetic Characterization of Accumulation of Polyhydroxyalkanoate from Styrene in Pseudomonas putida CA-3

    Science.gov (United States)

    O'Leary, Niall D.; O'Connor, Kevin E.; Ward, Patrick; Goff, Miriam; Dobson, Alan D. W.

    2005-01-01

    Pseudomonas putida CA-3 is capable of accumulating medium-chain-length polyhydroxyalkanoates (MCL-PHAs) when growing on the toxic pollutant styrene as the sole source of carbon and energy. In this study, we report on the molecular characterization of the metabolic pathways involved in this novel bioconversion. With a mini-Tn5 random mutagenesis approach, acetyl-coenzyme A (CoA) was identified as the end product of styrene metabolism in P. putida CA-3. Amplified flanking-region PCR was used to clone functionally expressed phenylacetyl-CoA catabolon genes upstream from the sty operon in P. putida CA-3, previously reported to generate acetyl-CoA moieties from the styrene catabolic intermediate, phenylacetyl-CoA. However, the essential involvement of a (non-phenylacetyl-CoA) catabolon-encoded 3-hydroxyacyl-CoA dehydrogenase is also reported. The link between de novo fatty acid synthesis and PHA monomer accumulation was investigated, and a functionally expressed 3-hydroxyacyl-acyl carrier protein-CoA transacylase (phaG) gene in P. putida CA-3 was identified. The deduced PhaG amino acid sequence shared >99% identity with a transacylase from P. putida KT2440, involved in 3-hydroxyacyl-CoA MCL-PHA monomer sequestration from de novo fatty acid synthesis under inorganic nutrient-limited conditions. Similarly, with P. putida CA-3, maximal phaG expression was observed only under nitrogen limitation, with concomitant PHA accumulation. Thus, β-oxidation and fatty acid de novo synthesis appear to converge in the generation of MCL-PHA monomers from styrene in P. putida CA-3. Cloning and functional characterization of the pha locus, responsible for PHA polymerization/depolymerization is also reported and the significance and future prospects of this novel bioconversion are discussed. PMID:16085828

  19. Preparation of RGO/Fe{sub 3}O{sub 4}/poly (acrylic acid) hydrogel nanocomposites with improved magnetic, thermal and electrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Didehban, K.H., E-mail: Didehban95@gmail.com; Mohammadi, L.; Azimvand, J.

    2017-07-01

    A hydrogel nanocomposite composed of reduced graphene oxide (RGO), iron oxide (Fe{sub 3}O{sub 4}) nanoparticles, and polyacrylic acid (PAA) was prepared using radical polymerization. Different percentages of RGO, Fe{sub 3}O{sub 4}, and PAA were used to prepare the nanocomposite. Fourier transform infrared spectroscopy (FTIR) results confirmed the formation of the nanocomposite’s chemical structure. X-ray power diffraction (XRD) patterns revealed the principal peak’s 2θ value to be 77.39° with the size of the nanocomposite particles estimated at 96 nm. Results indicated that the electrochemical capacity of the nanocomposites was controlled by the weight percentage of RGO. Increases to the potential scan rate reduced porosity and surface area, thereby decreasing the electrochemical capacity of the nanocomposites. Moreover, increasing the percentage of Fe{sub 3}O{sub 4} nanoparticles in the nanocomposites improved their magnetic characteristics and thermal properties. The latter also improved when the RGO percentage increased. - Highlights: • A hydrogel nanocomposite composed of RGO/Fe{sub 3}O{sub 4}/PAA was synthesized successfully. • Increasing the percentage of iron nanoparticles improved magnetic properties. • Increasing the percentage of RGO improved thermal and electrochemical capacity. • The Fe{sub 3}O{sub 4} nanoparticles directly affected magnetic properties.

  20. Morphology and Phase Transitions in Styrene-Butadiene-Styrene Triblock Copolymer Grafted with Isobutyl Substituted Polyhedral Oligomeric Silsesquioxanes (Postprint)

    National Research Council Canada - National Science Library

    Drazowski, Daniel B; Lee, Andre; Haddad, Timothy S

    2007-01-01

    Two symmetric triblock polystyrene-butadiene-polystyrene (SBS) copolymers with different styrene content were grafted with varying amounts of isobutyl-substituted polyhedral oligomeric silsesquioxane (POSS) molecules...

  1. Radiation preparation of nano-powdered styrene-butadiene rubber (SBR) and its toughening effect for polystyrene and high-impact polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Li Daishuang; Xia Haibing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peng Jing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)], E-mail: jpeng@pku.edu.cn; Zhai Maolin; Wei Genshuan; Li Jiuqiang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Qiao Jinliang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); SINOPEC, Beijing Research Institute of Chemical Industry, Beijing 100013 (China)

    2007-11-15

    Nano-powdered styrene-butadiene rubber (NPSBR) was synthesized based on the styrene-butadiene rubber (SBR) latex via gamma radiation crosslinking followed by spray drying. Two functional monomers, 2-ethyl hexyl acrylate (2-EHA) and trimethylolpropane triacrylate (TMPTA) were used as crosslinking agents. It was found that both 2-EHA and TMPTA can improve the radiation crosslinking of SBR latex. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed that the NPSBR has a particle size similar to that of SBR latex with a diameter of 100 nm due to the high degree of crosslinking of SBR. Mechanical testing results showed that NPSBR could toughen polystyrene (PS) and high-impact polystyrene (HIPS) effectively. In addition, NPSBR is more suitable to toughen HIPS than PS at low rubber content.

  2. In situ preparation of powder and the sorption behaviors of molecularly imprinted polymers through the complexation between polymer ion of methyl methacrylate/acrylic acid and Ca++ ion.

    Science.gov (United States)

    Chough, Sung Hyo; Park, Kwang Ho; Cho, Seung Jin; Park, Hye Ryoung

    2014-09-02

    Molecularly imprinted polymer (MIP) powders were prepared using a simple complexation strategy between the polymer carboxylate groups and template molecule followed by metal cation cross-linking of residual polymer carboxylates. Polymer powders were formed in situ by templating carboxylic acid containing polymers with 4-ethylaniline (4-EA), followed by addition of an aqueous CaCl2 solution. The solution remained homogeneous. The powders were prepared by precipitation by slowly adding a non-solvent, H2O, to the mixture. The resulting particles were very porous with uptake capacity that approached the theoretical value. We suggest two types of complexes are formed between the template, 4-EA, and polymer. The isolated entry type forms well defined cavities for the template with high specific selectivity, while the adjacent entry type forms wider binding sites without specific sorption for isomeric molecules. To evaluate conditions for forming materials with high affinity and selectivity, three MIPs were prepared containing 0.5, 1.0, and 1.5 equivalents of template to the base polymer. The MIP containing 0.5 eq showed higher specific selectivity to 4-EA, but the MIP containing 1.5 eq had noticeably lower selectivity. The lower selectivity is attributed to poorly formed binding sites with little selective sorption to any isomer when the higher ratio of template was used. However at the lower ratio of template the isolated entry is preferably formed to produce well defined binding cavities with higher selectivity to template. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Preparation, thermal property and morphology analysis of waterborne polyurethane-acrylate

    Science.gov (United States)

    Zhao, Zhenyu; Jing, Zefeng; Qiu, Fengxian; Dai, Yuting; Xu, Jicheng; Yu, Zongping; Yang, Pengfei

    2017-01-01

    A series of waterborne polyurethane-acrylate (WPUA) dispersions were prepared with isophorone diisocyanate (IPDI), polyether polyol (NJ-210), dimethylol propionic acid (DMPA), hydroxyethyl methyl acrylate (HEMA), different proportions of methyl methacrylate (MMA) and ethyl acrylate (MMA and EA) and initiating agent by the emulsion co-polymerization. The structures, thermal properties and morphology of WPUA films were characterized with FT-IR, DSC, SEM and AFM. Performances of the dispersions and films were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The obtained WPUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.

  4. Lipid-induced degradation in biocompatible poly(Styrene-Isobutylene-Styrene) (SIBS) thermoplastic elastomer.

    Science.gov (United States)

    Fittipaldi, Mauro; Grace, Landon R

    2017-04-01

    The thermoplastic elastomer Poly(Styrene-block-Isobutylene-block-Styrene) (SIBS) is highly biocompatible, which has led to its use in several commercially-available implants. However, lipid-induced degradation has been previously identified as a primary cause of failure in long-term SIBS implants subject to mechanical loading. Thus, understanding the mechanisms and extent of lipid-induced damage and the role of styrene-isobutylene ratio and molecular weight is critical to improving longevity of SIBS-based implants in order to fully exploit the biocompatibility advantages. Samples of four different SIBS formulations were fabricated via compression molding, immersed to lipid saturation contents from 5 to 80% by weight, and tested in uniaxial tension, stress relaxation, and dynamic creep modes. Degradation mechanisms were investigated via infrared spectroscopy, chromatography, and microscopy. No evidence of lipid-induced chemical interactions or chain scissoring was observed. However, a decrease in tensile strength, loss of dynamic creep performance and faster relaxation with increasing lipid content is attributed to strong internal straining. The magnitude of these losses is inversely proportional to both molecular weight and styrene content, suggesting that selection of these variables during the design phase should be based not only on the mechanical requirements of the application, but the expected degree of lipid exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Two decades of occupational (meth)acrylate patch test results and focus on isobornyl acrylate.

    Science.gov (United States)

    Christoffers, Wietske A; Coenraads, Pieter-Jan; Schuttelaar, Marie-Louise A

    2013-08-01

    Acrylates constitute an important cause of occupational contact dermatitis. Isobornyl acrylate sensitization has been reported in only 2 cases. We encountered an industrial process operator with occupational contact dermatitis caused by isobornyl acrylate. (i) To investigate whether it is relevant to add isobornyl acrylate to the (meth)acrylate test series. (ii) To report patients with (meth)acrylate contact allergy at an occupational dermatology clinic. Our patch test database was screened for positive reactions to (meth)acrylates between 1993 and 2012. A selected group of 14 patients was tested with an isobornyl acrylate dilution series: 0.3%, 0.1%, 0.033%, and 0.01%. Readings were performed on D2, D3, and D7. One hundred and fifty-one patients were tested with our (meth)acrylate series; 24 had positive reactions. Most positive reactions were to 2-hydroxypropyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, and diethyleneglycol diacrylate. Hypothetical screening with 2-hydroxypropyl acrylate, ethyleneglycol dimethacrylate, ethoxylated bisphenol A glycol dimethacrylate and trimethylolpropane triacrylate identified 91.7% of the 24 patients. No positive reactions were observed in 14 acrylate-positive patients tested with the isobornyl acrylate dilution series. The 0.3% isobornyl acrylate concentration induced irritant reactions in 3 patients. We report a rare case of allergic contact dermatitis caused by isobornyl acrylate. However, this study provides insufficient support for isobornyl acrylate to be added to a (meth)acrylate series. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Toward pH-responsive coating materials--high-throughput study of (meth)acrylic copolymers.

    Science.gov (United States)

    Krieg, Andreas; Arici, Elif; Windhab, Norbert; Schattka, Jan Hendrik; Schubert, Stephanie; Schubert, Ulrich S

    2014-08-11

    The release behavior of a model compound (β-naphthol orange) encapsulated in (meth)acrylate-based statistical copolymers under different environmental conditions was investigated. From monomers of varying polarity (methyl acrylate, ethyl acrylate, tert-butyl acrylate, 2-ethylhexyl methacrylate, and benzyl methacrylate) in combination with methacrylic acid, five polymer series were synthesized by free radical polymerization. The pH-dependent release kinetics were investigated via UV-vis spectroscopy at pH 1.2 and 6.8, simulating physiological conditions in the stomach and intestines. Furthermore, the influence of different ethanol contents (0 and 40 vol %) in the acidic medium was investigated. The whole approach was designed to meet the requirements of a high-throughput experimentation workflow.

  7. Electrochemical characterization of aminated acrylic conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Norma Mohammad [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Heng, Lee Yook [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia); Ling, Tan Ling [Southeast Asia Disaster Prevention Research Initiative, Lestari Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  8. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified styrene, divinylbenzene polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical...

  9. Synthesis and antibacterial activities of cyclodimers of styrene oxides

    African Journals Online (AJOL)

    A simple synthetic procedure for preparation of 1,4-dioxanes or 1,3-dioxolanes from styrene oxides is described. Electron-donating groups on the aromatic ring of the styrene oxides were found to favour formation of 1,4-dioxanes while electron-withdrawing groups favoured formation of 1,3-dioxolanes. Antibacterial activities ...

  10. Characterization of methacrylated alginate and acrylic monomers as versatile SAPs.

    Science.gov (United States)

    Mignon, Arn; Vermeulen, Jolien; Graulus, Geert-Jan; Martins, José; Dubruel, Peter; De Belie, Nele; Van Vlierberghe, Sandra

    2017-07-15

    Superabsorbent polymers (SAPs) based on polysaccharides, especially alginate, could offer a valuable solution in a plethora of applications going from drug delivery to self-healing concrete. This has already been proven with both calcium alginate and methacrylated alginate combined with acrylic acid. In this manuscript, the effect of varying the degree of methacrylation and use of a combination of acrylic acid and acrylamide is investigated to explore the effects on the relevant SAP characteristics. The materials showed high gel fractions and a strong swelling capacity up to 630gwater/gSAP, especially for superabsorbent polymers with a low degree of substitution. The SAPs also showed only a limited hydrolysis in aqueous and cement filtrate solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Sulfonation and characterization of styrene-indene copolymers for the development of proton conducting polymer membranes

    Directory of Open Access Journals (Sweden)

    Cristiane M. Becker

    2012-01-01

    Full Text Available The aim of this work is to obtain polymer precursors based on styrene copolymers with distinct degrees of sulfonation, as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the performance of the polyelectrolyte was evaluated based on the content of acid polar groups incorporated into the macromolecular chain. Polymeric films were produced by blending the sulfonated styrene-indene copolymer with poly(vinylidene fluoride. The degree of sulfonation of the polymer was strongly affected by the sulfonation reaction parameters, with a direct impact on the ionic exchange capacity and the ionic conductivity of the sulfonated polymers and the membranes obtained from them. The films produced with the blends showed more suitable mechanical properties, although the conductivity of the membranes was still lower than that of commercially available membranes used in fuel cells.

  12. Synthesis of polyaniline catalysed by Cu(I), Ni(II) and Fe(II) supported on the polyethylene-i-acrylic acid copolymer; Sintesis de polianilina catalizada por Cu(I), Ni(II) y Fe(II), soportados en el copolimero polietileno-i-acido acrilico

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, L.; Urena, F.; Lopez, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    In this study the active sites of acrylic acid (AA) were grafted in low density polyethylene (PEBD) using gamma radiation. Subsequently, the graft copolymer PEBD-i-AA was coordinated with different metals such as copper, nickel and iron. The organometallic copolymers so formed were used as catalysts in the aniline polymerization reaction. Finally, it was realized the characterization of the obtained products, determining their thermal properties, copolymer graft percentage, quantification of the metal contained in the complex as well as polymerization and electric conductivity percentages of the poly aniline film. (Author)

  13. Grafting of styrene onto polypropylene membranes

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa A.; Geraldes, Adriana N.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: helozen@ipen.br

    2007-07-01

    The grafting of styrene onto polypropylene (PP) by simultaneous radiation was carried out. The effects of absorbed dose and the pos radiation period on the grafting yield were investigated. The experiment comprised PP films with 40{mu}m thickness exposed to gamma ionizing radiation at room temperature and nitrogen atmosphere. The films were immersed in styrene/toluene and then irradiated at total dose of 40, 80 and 100 kGy. After irradiation the samples were evaluated at periods of 0, 7, 14, 21 and 28 days at room temperature in order to observe the behavior of grafting degree. Structural, chemical changes and surface morphologies of the modified PP films were characterized by infrared spectroscopic analysis (FTIR), differential scanning calorimetry analysis (DSC), thermogravimetric analysis (TGA) and the degree of grafting (DOG) was gravimetrically determined. The simultaneous radiation indicated the dependency of the percent graft on the absorbed dose. The DOG values are higher when the film was submitted at 100 kGy dose. The thermal stability shows a decrease in the degradation temperature of the modified samples in comparison with the pure polymer. (author)

  14. 75 FR 9438 - Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas Styrenics, LLLC Formerly Known as...

    Science.gov (United States)

    2010-03-02

    ... Americas Styrenics LLC, including on- site leased workers from Pioneer Pipe Co., Marietta, Ohio. The notice... Employment and Training Administration Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas... Pioneer Pipe Co.: Marietta, OH; Amended Certification Regarding Eligibility To Apply for Worker Adjustment...

  15. Occupational allergic contact dermatitis caused by photobonded sculptured nails and a review of (meth) acrylates in nail cosmetics.

    Science.gov (United States)

    Kanerva, L; Lauerma, A; Estlander, T; Alanko, K; Henriks-Eckerman, M L; Jolanki, R

    1996-06-01

    Mono(meth)acrylates (monoacrylates and monomethacrylates) are moderate to strong sensitizers. They are used in the production of a great variety of polymers, including nail cosmetics. A patient who became occupationally sensitized to photobonded sculptured nails is reported. Detailed patch testing and analyses of the patient's nail cosmetics containing mono(meth)acrylates clarified the cause of her hand and face dermatitis. The current knowledge on mono(meth)acrylates in nail cosmetics is also reviewed. Patch testings with conventional methods, including patch testing with the patient's own substances, were performed. The patient's nail cosmetics suspected of containing mono(meth)acrylates were analyzed with gas chromatography/mass spectrometry analysis. In the (meth)acrylate series, 15 of the 31 (meth)acrylate compounds tested gave an allergic reaction: 2 acrylates, 5 methacrylates, 3 dimethacrylates, and 5 diacrylates. Epoxy diacrylates, cyanoacrylate, triacrylates, and methacrylic acid were negative. Three of seven of her own nail cosmetic preparations contained mono(meth)acrylates as revealed by the gas chromatography/mass spectrometry analysis, and these also gave allergic patch test reactions, namely, the nail liquid, nail hardener, and UV-cured nail gel. The patient probably had been sensitized to the following (meth)acrylate compounds from her nail cosmetics: tripropylene glycol diacrylate and methyl acrylate from her photobonded nail gel; ethyl methacrylate, triethylene glycol dimethacrylate, and methyl methacrylate from her nail liquid; and butyl methacrylate from her nail hardener. She was probably also sensitized to the rare sensitizer aliphatic urethane diacrylate, but the source was not verified. Because nail cosmetics containing mono(meth)acrylates are strong sensitizers, both the workers and the customers should be aware of their sensitizing capacity; they should use no-touch techniques regarding the skin before the mono(meth)acrylates are

  16. Effect of modified graphene and microwave irradiation on the mechanical and thermal properties of poly(styrene-co-methyl methacrylate)/graphene nanocomposites

    KAUST Repository

    Zubair, Mukarram

    2014-08-04

    The effect of modified graphene (MG) and microwave irradiation on the interaction between graphene (G) and poly(styrene-co-methyl meth acrylate) [P(S-co-MMA)] polymer matrix has been studied in this article. Modification of graphene was performed using nitric acid. P(S-co-MMA) polymer was blended via melt blending with pristine and MG. The resultant nanocomposites were irradiated under microwave at three different time intervals (5, 10, and 20 min). Compared to pristine graphene, MG showed improved interaction with P(S-co-MMA) polymer (P) after melt mixing and microwave irradiation. The mechanism of improved dispersion and interaction of modified graphene with P(S-co-MMA) polymer matrix during melt mixing and microwave irradiation is due to the presence of oxygen functionalities on the surface of MG as confirmed from Fourier transform infrared spectroscopy. The formation of defects on modified graphene and free radicals on P(S-co-MMA) polymer chains after irradiation as explained by Raman spectroscopy and X-Ray diffraction studies. The nanocomposites with 0.1 wt% G and MG have shown a 26% and 38% increase in storage modulus. After irradiation (10 min), the storage modulus further improved to 11.9% and 27.6% of nanocomposites. The glass transition temperature of nanocomposites also improved considerably after melt mixing and microwave irradiation (but only for polymer MG nanocomposite). However, at higher irradiation time (20 min), degradation of polymer nanocomposites occurred. State of creation of crosslink network after 10 min of irradiation and degradation after 20 min of irradiation of nanocomposites was confirmed from SEM studies. Copyright © 2014 John Wiley & Sons, Ltd.

  17. Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating

    Directory of Open Access Journals (Sweden)

    Lili Handayani

    2015-01-01

    Full Text Available The low-efficiency problem in fertilizer application can be overcome by controlling fertilizer solubility, i.e. by rendering the fertilizer to be released gradually; such material is also known as slow-release fertilizer (SRF. This research was aimed to formulate SRF by coating technique using acrylic and chitosan as the coating material, and to evaluate fertilizer resistance to too fast disintegration, and rate of nutrient release method. The results demonstrated that fertilizer formulation containing N, P, K, Fe, Cu, and Zn with granulation technique yielded 74% of granules with 2-5 mm in diameter. The SRFs (formulated fertilizer with acrylic or chitosan coating were more resistant to water pounding than non-SRF. Furthermore, shaking test with distilled water or 2% citric acid, or by percolation test with distilled water showed that the SRFs had lower nutrient solubility than the non-SRFs. The results of shaking test also specifically indicated that coating with acrylic made the fertilizer more resistant to the citric acid,suggesting that this coating material would be more suitable in acidic soils. The SRFs formulated with the addition of chitosan during blending of micronutrients prior to mixing with macronutrients, granulation, and final coating exhibited lower nutrient solubility than the SRFs without the pre-coating chitosan addition.

  18. 3-(Phenyl-carbamoyl)acrylic acid.

    Science.gov (United States)

    Jin, Shouwen; Huang, Yanfei; Wei, Shuaishuai; Zhou, Yong; Zhou, Yingping

    2012-09-01

    In the title compound, C(10)H(9)NO(3), the dihedral angle between the phenyl ring and the amide group is 10.8 (2)°. The C=O and O-H bonds of the carboxyl group adopt an anti orientation and an intra-molecular O-H⋯O hydrogen bond closes an S(7) ring. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into C(7) chains propagating in [101]. The packing is consolidated by C-H⋯O inter-actions, generating sheets aligned at an angle of ca 60° with the bc plane.

  19. [Treatment of high-concentration butyl-acrylate-production wastewater by A three-phase biological fluidized bed reactor].

    Science.gov (United States)

    Fan, Zhi-qing; Song, Yu-dong; Zhou, Yue-xi; Liang, Han-dong

    2011-05-01

    The butyl-acrylate-production wastewater was treated by a three-phase biological fluidized bed reactor. The influences of acrylic acid concentrations, p-toluenesulfonic acid concentrations, volumic load and hydraulic retention time on pollutants removal efficiencies were investigated. It was indicated that the reactor was suitable for the treatment of butyl-acrylate-production wastewater at a high loading rate. Acrylic acid of 100 mg/L or p-toluenesulfonic acid of 50 mg/L in the influent can inhibit the unacclimated microorganisms in the fluidized bed reactor. The inhibition effects were eliminated after an acclimation of two weeks. Acrylic acid and p-toluenesulfonic acid could be removed completely at COD loading rates up to 11.56-13.56 kg/(m3 x d). The effluent COD could satisfy the demand of Class II in Chinese Integrated Wastewater Discharge Standard (GB 8978-1996) at COD loading rates up to 8.86 kg/(m3 x d) when influent COD concentration is below 2000 mg/L. When the influent COD concentration was increased to 9550-11,800 mg/L(acrylic acid of 6244 mg/L and p-toluenesulfonic acid of 1000 mg/L), the effluent COD was 271-360 mg/L, which satisfied the demand of Class III in Chinese Integrated Wastewater Discharge Standard (GB 8978-1996) at COD loading rates of 7.96-9.83 kg/(m3 x d).

  20. METHACRYLATE AND ACRYLATE ALLERGY IN DENTAL STUDENTS.

    OpenAIRE

    Maya Lyapina; Assya Krasteva; Maria Dencheva; Mariana Tzekova; Angelina Kisselova-Yaneva

    2013-01-01

    A multitude of acrylic monomers is used in dentistry, and when dental personnel, patients or students of dental medicine become sensitized, it is of great importance to identify the dental ;acrylic preparations to which the sensitized individual can be exposed. Numerous studies confirm high incidence of sensitization to (meth) acrylates in dentatal professionals, as well as in patients undergoing dental treatment and exposed to resin-based materials. Quite a few studies are available aiming t...

  1. Glycophorin A somatic cell mutation frequencies in Finnish reinforced plastics workers exposed to styrene.

    Science.gov (United States)

    Bigbee, W L; Grant, S G; Langlois, R G; Jensen, R H; Anttila, A; Pfäffli, P; Pekari, K; Norppa, H

    1996-10-01

    We have used the glycophorin A (GPA) in vivo somatic cell mutation assay to assess the genotoxic potential of styrene exposure in 47 reinforced plastics workers occupationally exposed to styrene and 47 unexposed controls matched for age, gender, and active smoking status. GPA variant erythrocyte frequencies (Vf), reflecting GPA allele loss (phi/N) and allele loss and duplication (N/N) somatic mutations arising in vivo in the erythroid progenitor cells of individuals of GPA M/N heterozygous genotype, were flow cytometrically determined in peripheral blood samples from these subjects. Measurements of styrene exposure of the workers at the time of blood sampling showed a mean 8-h time-weighted average (TWA8-h) styrene concentration of 155 mg/m3 (37 ppm) in the breathing zone. Mean urinary concentrations of the styrene metabolites mandelic acid (MA) and mandelic acid plus phenyl glyoxylic acid (MA+PGA) were 4.4 mmol/liter (after workshift) and 2.1 mmol/liter (next morning), respectively. Multivariate analysis of covariance on log-transformed GPA Vf data with models allowing adjustment for age, gender, smoking status, and styrene exposure showed that N/N Vf were nearly significantly increased among all of the exposed workers (adjusted geometric mean, 6.3 per million versus 5.0 in the controls; P = 0.058) and were statistically significantly elevated (adjusted geometric mean, 6.8 versus 5.0 in the controls; P = 0.036) among workers classified into a high-exposure group according to personal TWA8-h concentration of styrene in the breathing zone of > or = 85 mg/m3 (20 ppm; Finnish threshold limit value). Women in this high exposure group showed especially elevated N/N Vf (adjusted geometric mean 8.5 versus 5.3 in control women; P = 0.020); this elevation was also significant if urinary MA+PGA of > or = 1.2 mmol/liter was used as the basis of classification (adjusted geometric mean, 8.3; P = 0.030). The occupational exposure could not be shown to influence phi/N Vf

  2. Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

  3. Contact dermatitis from acrylics in a histology laboratory assistant.

    Science.gov (United States)

    Molina, Luciana; Amado, Antoine; Mattei, Peter L; Taylor, James S

    2009-01-01

    The use of acrylics has expanded enormously, resulting in a vast range of products for both occupational and non-occupational purposes. Acrylics reported to cause allergic contact dermatitis in histology technicians are 2-hydroxyethyl methacrylate and 2-hydroxyethel acrylate.

  4. In situ reactive compatibilization of natural rubber/acrylic-bentonite composites via peroxide-induced vulcanization

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lihua; Lei, Zhiwen [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Xu, Chuanhui, E-mail: xuhuiyee@gxu.edu.cn [Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Yukun, E-mail: cyk@scut.edu.cn [The Key Laboratory of Polymer Processing Engineering, Ministry of Education, China(South China University of Technology), Guangzhou, 510640 (China)

    2016-02-15

    To achieve good interfacial interaction between fillers and rubber matrix is always a hot topic in rubber reinforcing industry. In this paper, acid activated bentonite (Bt) was alkalified to be alkaline calcium-bentonite (ACBt), then acrylic acid (AA) was employed to modify ACBt to obtain acrylic-bentonite (ABt). The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) illustrated that acrylate groups were chemically boned onto the surface of Bt and the layer spacing of Bt was increased. During peroxide-induced vulcanization, in situ compatibilization of ABt was realized via the reaction between the unsaturated bonds of acrylate groups on the surface of Bt and the natural rubber (NR) chains. This resulted in an enhanced cross-linked network which contributed to the improved mechanical properties of NR/ABt composites. - Highlights: • Acrylate groups were chemically boned onto the surface of bentonite. • In situ compatibilization was realized via the reaction of acrylate group and NR. • ABt particles participated in forming the NR crosslink network. • A potential reinforcing material options for “white” rubber products.

  5. The Effect of Hydrogen Bonding on Radical Semi-Batch Copolymerization of Butyl Acrylate and 2-Hydroxyethyl Acrylate

    National Research Council Canada - National Science Library

    Jan E S Schier; David Cohen-Sacal; Owen R Larsen; Robin A Hutchinson

    2017-01-01

    The radical copolymerization of butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA) was investigated under batch and semi-batch operations, with a focus on the influence of hydrogen-bonding on acrylate backbiting...

  6. Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h{sup -1} from a {sup 60}Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

  7. Acrylated Composite Hydrogel Preparation and Adsorption Kinetics of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Jinpeng Wang

    2017-10-01

    Full Text Available By using cyclodextrin (α-CD self-assembly into a hydrogel with the triblock copolymer Pluronic F127, nanomicrocrystalline cellulose was introduced into a gel system to form a composite CNC-β-CD/α-CD/Pluronic F127 hydrogel (CCH. CCH was modified further by grafting acrylic acid to form a novel acrylated composite hydrogel (ACH. The swelling degree of ACH was 156 g/g. Adsorption isotherms show that the adsorption process for methylene blue proximity fitted the Freundlich model. The adsorption kinetics showed that ACH followed a quasi-second-order kinetic model. Methylene blue desorption showed that ACH was a temperature- and pH-dependent gel. Repeated adsorption and desorption experiments were carried out three times, and the removal rate of methylene blue at 75 mg/L was still 70.1%.

  8. Surface modification of nanoparticles for radiation curable acrylate clear coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, F. E-mail: fbauer@rz.uni-leipzig.de; Glaesel, H.-J.; Hartmann, E.; Bilz, E.; Mehnert, R

    2003-08-01

    To obtain transparent, scratch and abrasion resistant coatings a high content of nanosized silica and alumina filler was embedded in radiation-curable acrylate formulations by acid catalyzed silylation using trialkoxysilanes. {sup 29}SiMAS NMR and MALDI-TOF mass spectrometry were employed to elucidate the structure of the surface-grafted methacryloxypropyl-, vinyl- and n-propyl-trimethoxysilane. In accordance with NMR findings, MALDI-TOF MS showed highly condensed oligomeric siloxanes of more than 20 monomeric silane units. A ladder-like structure of bound polysiloxanes is proposed rather than a simplified picture of tridentate silane bonding. Hence, silane coupling agents do not only modify the chemical nature of the filler surface but also strongly effect the rheological properties of the acrylate nanodispersions.

  9. Occupational contact allergy to (meth)acrylates.

    Science.gov (United States)

    Geukens, S; Goossens, A

    2001-03-01

    Among 13,833 patients suspected of contact dermatitis examined during the years 1978-1999, occupational contact allergy to (meth)acrylates was diagnosed in 31 patients. The 3 most common sensitizers were ethyleneglycol dimethacrylate (17 positive patch tests), 2-hydroxyethyl methacrylate (14) and triethyleneglycol dimethacrylate (6). The aim of this report was to assess the different occupations and industries responsible for occupational sensitization to (meth)acrylates. 14 of the 31 patients work in the dental sector, either as a dentist or as a student of dental technology, where (meth)acrylate-containing dental prostheses and dental composites are mainly responsible for allergy to (meth)acrylates. An increasing trend in dermatological problems related to the expansion of the use of (meth)acrylates is clearly reflected in the patient population of our dermatology department.

  10. Relation between colour vision loss and occupational styrene exposure level

    OpenAIRE

    Gong, Y; Kishi, R.; Katakura, Y; Tsukishima, E; Fujiwara, K.; Kasai, S; Satoh, T.; Sata, F; Kawai, T.

    2002-01-01

    Aims: To investigate the relation between colour vision loss and the exposure level of styrene. Exposure level included the current exposure concentration, past cumulative exposure, and the maximum exposure level in the past.

  11. Dynamic response of acrylonitrile butadiene styrene under impact loading

    National Research Council Canada - National Science Library

    Owolabi, Gbadebo; Peterson, Alex; Habtour, Ed; Riddick, Jaret; Coatney, Michael; Olasumboye, Adewale; Bolling, Denzell

    2016-01-01

    ... rateloading.Tensile tests were conducted on 3-D printed acrylonitrile butadiene styrene (ABS) at differentstrain rates, according to the ASTM D638 standard, to assess its strain rate sensitivity under quasi-staticloads...

  12. Styrene-Associated Health Outcomes at a Windblade Manufacturing Plant

    Science.gov (United States)

    McCague, Anna-Binney; Cox-Ganser, Jean M.; Harney, Joshua M.; Alwis, K. Udeni; Blount, Benjamin C.; Cummings, Kristin J.; Edwards, Nicole; Kreiss, Kathleen

    2015-01-01

    Background Health risks of using styrene to manufacture windblades for the green energy sector are unknown. Methods Using data collected from 355 (73%) current windblade workers and regression analysis, we investigated associations between health outcomes and styrene exposure estimates derived from urinary styrene metabolites. Results The median current styrene exposure was 53.6 mg/g creatinine (interquartile range: 19.5–94.4). Color blindness in men and women (standardized morbidity ratios 2.3 and 16.6, respectively) was not associated with exposure estimates, but was the type previously reported with styrene. Visual contrast sensitivity decreased and chest tightness increased (odds ratio 2.9) with increasing current exposure. Decreases in spirometric parameters and FeNO, and increases in the odds of wheeze and asthma-like symptoms (odds ratios 1.3 and 1.2, respectively) occurred with increasing cumulative exposure. Conclusions Despite styrene exposures below the recommended 400 mg/g creatinine, visual and respiratory effects indicate the need for additional preventative measures in this industry. PMID:26305283

  13. Matrix-assisted laser desorption/ionization sample preparation optimization for structural characterization of poly(styrene-co-pentafluorostyrene) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Tisdale, Evgenia; Kennedy, Devin; Wilkins, Charles, E-mail: cwilkins@uark.edu

    2014-01-15

    Graphical abstract: -- Highlights: •We optimized sample preparation for MALDI TOF poly(styrene-copentafluorostyrene) co-polymers. •Influence of matrix choice was investigated. •Influence of matrix/analyte ratio was examined. •Influence of analyte/salt ratio (for Ag+ salt) was studied. -- Abstract: The influence of the sample preparation parameters (the choice of the matrix, matrix:analyte ratio, salt:analyte ratio) was investigated and optimal conditions were established for the MALDI time-of-flight mass spectrometry analysis of the poly(styrene-co-pentafluorostyrene) copolymers. These were synthesized by atom transfer radical polymerization. Use of 2,5-dihydroxybenzoic acid as matrix resulted in spectra with consistently high ion yields for all matrix:analyte:salt ratios tested. The optimized MALDI procedure was successfully applied to the characterization of three copolymers obtained by varying the conditions of polymerization reaction. It was possible to establish the nature of the end groups, calculate molecular weight distributions, and determine the individual length distributions for styrene and pentafluorostyrene monomers, contained in the resulting copolymers. Based on the data obtained, it was concluded that individual styrene chain length distributions are more sensitive to the change in the composition of the catalyst (the addition of small amount of CuBr{sub 2}) than is the pentafluorostyrene component distribution.

  14. Highly selective oxidation of styrene to benzaldehyde over a tailor-made cobalt oxide encapsulated zeolite catalyst.

    Science.gov (United States)

    Liu, Jiangyong; Wang, Zihao; Jian, Panming; Jian, Ruiqi

    2018-02-02

    A tailor-made catalyst with cobalt oxide particles encapsulated into ZSM-5 zeolites (Co 3 O 4 @HZSM-5) was prepared via a hydrothermal method with the conventional impregnated Co 3 O 4 /SiO 2 catalyst as the precursor and Si source. Various characterization results show that the Co 3 O 4 @HZSM-5 catalyst has well-organized structure with Co 3 O 4 particles compatibly encapsulated in the zeolite crystals. The Co 3 O 4 @HZSM-5 catalyst was employed as an efficient catalyst for the selective oxidation of styrene to benzaldehyde with hydrogen peroxide as a green and economic oxidant. The effect of various reaction conditions including reaction time, reaction temperature, different kinds of solvents, styrene/H 2 O 2 molar ratio and catalyst dosage on the catalytic performance were systematically investigated. Under the optimized reaction condition, the yield of benzaldehyde can achieve 78.9% with 96.8% styrene conversion and 81.5% benzaldehyde selectivity. Such an excellent catalytic performance can be attributed to the synergistic effect between the confined reaction environment and the proper acidic property. In addition, the reaction mechanism with Co 3 O 4 @HZSM-5 as the catalyst for the selective oxidation of styrene to benzaldehyde was reasonably proposed. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Toxicity of the components of styrene polymers: polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-butadiene-rubber (SBR). Reactants and additives.

    Science.gov (United States)

    Fishbein, L

    1984-01-01

    The toxicity of the components of styrene polymers, e.g., polystyrene, ABS and SBR, were reviewed with primary focus on the reactive monomers (except styrene) (e.g., acrylonitrile, butadiene) as well as on impurities and solvents such as benzene, hexane and methylethyl ketone, and additives such as phenyl-2-naphthylamine, di-n-butyl phthalate, and a number of peroxide initiators and flame retardants (e.g., 2,3-dibromopropanol, decadibromodiphenyl oxide and antimony trioxide). It is stressed that toxicity data are generally lacking for the majority of additives employed in the production of styrene polymers. Information is also lacking as to the numbers of individuals at potential risk and the extent of their exposure to the large number of additives employed.

  16. Differential sensitivities of the growth of Escherichia coli to acrylate under aerobic and anaerobic conditions and its effect on product formation.

    Science.gov (United States)

    Arya, Ajay S; Lee, Sarah A; Eiteman, Mark A

    2013-11-01

    The effect of acrylate on the growth of Escherichia coli was determined under aerobic and anaerobic conditions in glucose-defined medium. Growth occurred with up to 35 mM acrylate under aerobic conditions but ceased at 5 mM acrylate under anaerobic conditions. This differential sensitivity can be attributed to inhibition of pyruvate formate lyase and/or pflB gene repression, as this enzyme is necessary for anaerobic growth of E. coli. The effect of acrylate on end-product distribution was also determined by growing E. coli first aerobically, then switching to anaerobic conditions. In the absence of acrylate, E. coli generated the typical distribution of mixed-acid products, with about 12 % of pyruvate being metabolically converted to lactate. In contrast, in the presence of 5 mM acrylate, E. coli converted 83 % of pyruvate to lactate, consistent with a reduction in pyruvate formate lyase activity.

  17. Amphiphilic photosensitive dextran-g-poly(o-nitrobenzyl acrylate) glycopolymers.

    Science.gov (United States)

    Soliman, Soliman Mehawed Abdellatif; Colombeau, Ludovic; Nouvel, Cécile; Babin, Jérôme; Six, Jean-Luc

    2016-01-20

    Among all photosensitive monomers reported in the literature, o-nitrobenzyl acrylate (NBA) was selected in this present study. Two strategies were compared to produce azido-terminated poly(o-nitrobenzyl acrylate) (PNBA) using controlled Single Electron Transfer-Living Radical Polymerization (SET-LRP). In a parallel way, dextran (Dex) was modified by the introduction of several alkynyl-terminated hydrophobic chains. Finally, an Huisgen-type Copper (I)-catalyzed Azide-Alkyne Cycloaddition (CuAAC) click-chemistry was carried out to produce amphiphilic Dex-g-PNBA glycopolymers with different number and length of PNBA grafts. 2D DOSY (1)H NMR was used to prove the formation of such glycopolymers. Preliminary study on Dex-g-PNBA self-assembly was done by measuring the critical water content (CWC) above which Dex-g-PNBA started to auto-organize themselves to produce nano-objects. Finally, under UV irradiation, PNBA grafts turn into poly(acrylic acid) ones giving light-sensitive properties to such amphiphilic Dex-g-PNBA. Such properties were evaluated and compared with those of PNBA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Radiopurity measurement of acrylic for DEAP-3600

    Energy Technology Data Exchange (ETDEWEB)

    Nantais, C. M.; Boulay, M. G. [Department of Physics, Engineering Physics, and Astronomy, Queen' s University, Kingston, Ontario K7L 3N6 (Canada); Cleveland, B. T. [SNOLAB, Lively, Ontario P3Y 1N2 Canada and Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6 (Canada)

    2013-08-08

    The spherical acrylic vessel that contains the liquid argon target is the most critical detector component in the DEAP-3600 dark matter experiment. Alpha decays near the inner surface of the acrylic vessel are one of the main sources of background in the detector. A fraction of the alpha energy, or the recoiling nucleus from the alpha decay, could misreconstruct in the fiducial volume and result in a false candidate dark matter event. Acrylic has low levels of inherent contamination from {sup 238}U and {sup 232}Th. Another background of particular concern is diffusion of {sup 222}Rn during manufacturing, leading to {sup 210}Pb contamination. The maximum acceptable concentrations in the DEAP-3600 acrylic vessel are ppt levels of {sup 238}U and {sup 232}Th equivalent, and 10{sup −8} ppt {sup 210}Pb. The impurities in the bulk acrylic will be measured by vaporizing a large quantity of acrylic and counting the concentrated residue with ultra-low background HPGe detectors and a low background alpha spectrometer. An overview of the acrylic assay technique is presented.

  19. MODELING STYRENE HYDROGENATION KINETICS USING PALLADIUM CATALYSTS

    Directory of Open Access Journals (Sweden)

    G. T. Justino

    Full Text Available Abstract The high octane number of pyrolysis gasoline (PYGAS explains its insertion in the gasoline pool. However, its use is troublesome due to the presence of gum-forming chemicals which, in turn, can be removed via hydrogenation. The use of Langmuir-Hinshelwood kinetic models was evaluated for hydrogenation of styrene, a typical gum monomer, using Pd/9%Nb2O5-Al2O3 as catalyst. Kinetic models accounting for hydrogen dissociative and non-dissociative adsorption were considered. The availability of one or two kinds of catalytic sites was analyzed. Experiments were carried out in a semi-batch reactor at constant temperature and pressure in the absence of transport limitations. The conditions used in each experiment varied between 16 - 56 bar and 60 - 100 ºC for pressure and temperature, respectively. The kinetic models were evaluated using MATLAB and EMSO software. Models using adsorption of hydrogen and organic molecules on the same type of site fitted the data best.

  20. Poly(meth)acrylate-based coatings.

    Science.gov (United States)

    Nollenberger, Kathrin; Albers, Jessica

    2013-12-05

    Poly(meth)acrylate coatings for pharmaceutical applications were introduced in 1955 with the launch of EUDRAGIT(®) L and EUDRAGIT(®) S, two types of anionic polymers. Since then, by introducing various monomers into their polymer chains and thus altering their properties, diverse forms with specific characteristics have become available. Today, poly(meth)acrylates function in different parts of the gastrointestinal tract and/or release the drug in a time-controlled manner. This article reviews the properties of various poly(meth)acrylates and discusses formulation issues as well as application possibilities. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. [Styrene migration into wine contained in polyester resin tanks].

    Science.gov (United States)

    Giffone, M; Brun, S

    1978-01-01

    The use of polyester resins in wine tanks manufacture or coating has widely spread during the past five years; this type of material has been and is still the source of organoleptic damage due to non polymerized sytrene migration into urine. Sytrene is a solvant often used in resin polymerization: it act as a reticulation agent of insaturated linear polyester. Polymerization at room temperature is allowed gy additives but has to be completed in warm air or in steam. An excess of styrene is often used for a polymerisation as complete as possible and remains on a free form. Then it migrates from the tank walls into the wine. For a better understanding of the styrene migration mechanism studies were performed on two levels: from small containers (4 l) kept in the laboratory and from tanks (30 hl) set up in an I.N.R.A. wine estate in all conditions usually realized in practice. Influence of time, temperature and alcohol content were studied. Styrene migration was interpreted as a diffusion phenomenom and styrene diffusion coefficients were calculated for several temperatures. Knowledge of these coefficients and of styrene content of the tank walls allow the prediction of a tank behaviour in time. Other substances that styrene were detected in wine and in tank walls, they are impurities either from resins like ethylbenzene, or from the catalyst like mesityl oxide. The lattest has never been mentioned in the litterature. From the results obtained it is possible to give some advices to manufacturers and users of polyester resin tanks, about the quality of raw materials, resins and additives along with the conditions carried and for their use and about the control of monomer styrene content in the walls of just manufactured tank.

  2. Spectrophotometric study of the interaction of methylene blue with poly(styrene-co-sodium styrene sulfonate

    Directory of Open Access Journals (Sweden)

    Souha Ben Mahmoud

    2016-05-01

    Full Text Available The interaction of the cationic phenothiazine dye, the Methylene Blue (MB with poly-(sodium styrene sulfonatef–co-(styrene1-f, (PSSNa f, has been investigated by spectrophotometric method. The polyelectrolyte induced metachromasy resulting in a blue shift of the absorption maxima of the dye, in agreement with the formation of dye H-aggregates. The stability of the PSSNa-MB complexes was studied as a function of polyelectrolyte chain length, polyelectrolyte electrostatic charge density f, polyelectrolyte concentration, NaCl salt addition, tetrahydrofurane (THF addition and THF treatment. The stoichiometry of PSSNa-MB complex evaluated by the molar ratio method was found 4:1 for the fully charged PSSNa f = 1. Reversal of metachromasy was observed upon salt and THF addition, while THF treatment does not affect the complex and allows recovering the initial complex. Finally, thermodynamic parameters of the interaction between the polyelectrolyte and the dye at different temperatures, namely free energy DG, the enthalpy DH and the entropy DS have been evaluated to determine the binding constant and as a consequence the stability of the complex. The metachromasy effect was found to be more high as the chemical charge f increases and reaches its maximum value f = 1, when operating at optimal conditions. So, the PSSNa f = 1-MB complex is the most stable in comparison to the others based on lower charge density PSSNa f.

  3. Bonding of autopolymerizing acrylic resins to magnetic stainless steel alloys using metal conditioner.

    Science.gov (United States)

    Shimizu, Hiroshi; Tsue, Fumitake; Chen, Zhao-Xun; Kawaguchi, Tomohiro; Takahashi, Yutaka

    2008-02-01

    The shear bond strengths of a barbituric acid derivative-activated autopolymerizing acrylic resin to two magnetic stainless steel alloys using a metal conditioner were investigated. The surfaces of the two magnetic stainless steel alloys were abraded with 600-grit silicon carbide paper. The surface preparations were: Group 1 (without preparation), Group 2 (airborne particle abrasion with 50 microm alumina), and Group 3 (airborne particle abrasion followed by priming with a metal conditioner). The alloys were bonded with a barbituric acid derivative-activated autopolymerizing acrylic resin. For comparison, airborne particle abrasion and bonding with a tri-n-butylborane-initiated autopolymerizing acrylic resin (Group 4), as well as airborne particle abrasion followed by priming with a metal conditioner and bonding with the same resin (Group 5) were added. Half of the specimens were thermocycled up to 10,000 cycles. The shear bond strengths were determined. Group 3 had significantly improved shear bond strengths with the barbituric acid derivative-activated autopolymerizing acrylic resin to both stainless steel alloys. Although there were no significant differences in the bond strength among Groups 3-5 before thermocycling, the decrease in the bond strength of Group 3 was considerably greater than that of Groups 4 or 5 after thermocycling for both stainless steel alloys. Significant improvements in the bond strength of the barbituric acid derivative-activated autopolymerizing acrylic resin to two magnetic stainless steel alloys were achieved by airborne particle abrasion followed by priming with the metal conditioner. The bond durability to this resin, however, was inferior to that to a tri-n-butylborane-initiated autopolymerizing acrylic resin.

  4. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran

    Directory of Open Access Journals (Sweden)

    Sari Fouad

    2012-12-01

    Full Text Available We reported in this work that the cationic copolymerization in one step takes place between carbon–carbon double-bond monomer styrene with cyclic monomer tetrahydrofuran. The comonomers studied belong to different families: vinylic and cyclic ether. The reaction is initiated with maghnite-H+ an acid exchanged montmorillonite as acid solid ecocatalyst. Maghnite-H+ is already used as catalyst for polymerization of many vinylic and heterocyclic monomers. The oxonium ion of tetrahydrofuran and carbonium ion of styrene propagated the reaction of copolymerization. The acetic anhydride is essential for the maintenance of the ring opening of tetrahydrofuran and the entry in copolymerization. The temperature was kept constant at 40°C in oil bath heating for 6 hours. A typical reaction product was analyzed by 1H-NMR, 13C-NMR and IR and the formation of the copolymer was confirmed. The reaction was proved by matched with analysis. The maghnite-H+ allowed us to obtain extremely pure copolymer in good yield by following a simples operational conditions. Copyright © 2012 by BCREC UNDIP. All rights reservedReceived: 29th October 2012; Revised: 29th November 2012; Accepted: 29th November 2012[How to Cite: S. Fouad, M.I. Ferrahi, M. Belbachir. (2012. Copolymerization of Carbon–carbon Double-bond Monomer (Styrene with Cyclic Monomer (Tetrahydrofuran. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 165-171. (doi:10.9767/bcrec.7.2.4074.165-171][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4074.165-171 ] | View in 

  5. Ultraviolet curing of acrylated liquid natural rubber for surface coating application

    Directory of Open Access Journals (Sweden)

    Kannikar Kwanming

    2009-01-01

    Full Text Available Ultraviolet curable acrylated liquid natural rubber was prepared by grafting of photosensitive molecule onto liquid natural rubber for surface coating application. The liquid natural rubber (LNR was firstly obtained by degradation of natural rubber latex with hydrogen peroxide and cobalt acetylacetonate at 65oC for 72 hrs. The preparation of acrylated natural rubber was carried out by the reaction of acrylic acid and epoxidized liquid natural rubber (ELNR prior obtained from LNR with formic acid and hydrogen peroxide in the ratio of 2:1 by weight in toluene at 80oC for 6, 9, 12, 18, and 24 hrs. It was found that the percentage of acrylate grafted onto liquid natural rubber depended on the reaction time. Surface coating was performed by using acrylated liquid natural rubber and 1,6-hexanediol diacrylate (HDDA or tripropylene glycol diacrylate (TPGDA as a crosslinker and Irgarcure 184 or Irgarcure 651 as a photoinitiator under UV exposure for 30, 60, and 90 seconds. The hardness test of cured products was investigated using the Pencil hardness test at pencil level of 2B to 6H. It was found that the highest hardness of surface coating was at pencil level of 4H for the product using TPGDA and Irgacure 651 in the ratio of 80:10 parts per hundred of rubber (phr. The cured products were able to resist to 2% H2SO4 and distilled water for more than 24 hrs.

  6. Disinfection of denture base acrylic resin.

    Science.gov (United States)

    Lin, J J; Cameron, S M; Runyan, D A; Craft, D W

    1999-02-01

    During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected. This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins. Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time. Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking. Analysis was performed with microbial colony counts, SEM, and statistical analyses. Viable microorganisms still remain on the internal and external surfaces of treated resins. Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

  7. Resistance of acrylic vessel to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  8. A novel (S)-(+)-decursin derivative, (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]chromen-3-yl-ester, inhibits ovalbumin-induced lung inflammation in a mouse model of asthma.

    Science.gov (United States)

    Yang, Eun Ju; Song, Gyu-Yong; Lee, Ji-Sook; Yun, Chi-Young; Kim, In Sik

    2009-03-01

    (S)-(+)-Decursin is a coumarin compound present in herbal extracts that has various biological activities. (S)-(+)-Decursin attenuates pathophysiologic progression in cancer, bacterial infection and neuropathy. Asthma is an inflammatory disease associated with increased infiltration of leukocytes, especially eosinophils, and secretion of mucus into the airways. Although (S)-(+)-decursin, as well as (S)-(+)-decursin analogues, have various pharmacological properties, the effect of these compounds on asthma is not known. In the present study, we synthesized (S)-(+)-3-(3,4-dihydroxy-phenyl)-acrylic acid 2,2-dimethyl-8-oxo-3,4-dihydro-2H,8H-pyrano[3,2-g]chromen-3-yl-ester (compound 6, C6) from (S)-(+)-decursin and examined if C6 had any inhibitory effects on lung inflammation in a mouse model of ovalbumin-induced asthma. C6 significantly inhibited the leukocytosis (p allergic airway diseases.

  9. Clinical properties of a novel, glistening-free, single-piece, hydrophobic acrylic IOL

    Directory of Open Access Journals (Sweden)

    Packer M

    2014-02-01

    Full Text Available Mark Packer,1 Mohan Rajan,2 Edoardo Ligabue,3 Peter Heiner4 1Oregon Health and Science University, Portland, OR, USA; 2Rajan Eye Care Hospital Pvt Ltd, Chennai, India; 3Ophthalmology Department, Centro Diagnostico Italiano, Milan, Italy; 4Bond University Medical School, Robina, QLD, Australia Abstract: A new, single-piece, hydrophobic acrylic lens – the first constructed with a lens optic and haptics comprised of a hydroxyethyl methacrylate-polyethylene glycol phenyl ether acrylate–styrene copolymer, cross-linked with ethylene glycol dimethacrylate, and labeled as "glistening-free" – was recently introduced globally. Glistenings have been a significant source of clinical concern with previous hydrophobic lens designs. This new monofocal lens provides enhanced, clear optics for lens-based surgery. The superior optical clarity of this lens is achieved through the elimination of glistenings, enhanced surface durability, high refractive index, a high Abbe number, and an aspheric design. Additionally, the lens design reduces the risk of developing posterior capsule opacification. Keywords: glistenings, monofocal hydrophobic acrylic, IOL, aspheric

  10. Multi-functional hybrid coatings containing silica nanoparticles and anti-corrosive acrylate monomer for scratch and corrosion resistance.

    Science.gov (United States)

    Seo, Ji Yeon; Han, Mijeong

    2011-01-14

    Multi-functional hybrid coatings having both anti-corrosion and scratch resistance were prepared from modified silica nanoparticles and functional acrylates. To improve the dispersion properties of silica nanoparticles in the organic/inorganic hybrid coatings, the surface of the nanoparticles was modified with γ-methacryloxypropyltrimethoxysilane. The coating solution could be prepared by mixing modified silica nanoparticles, tetrasiloxane acrylate, di-acrylate monomer containing an anti-corrosion functional group, acrylic acid, and an initiator in a solvent. The mixture was then dip-coated on iron substrates and finally polymerized by ultraviolet (UV) irradiation. Corrosion and scratch resistance of the coated iron was evaluated by electrochemical impedance spectroscopy (EIS) and a pencil hardness test, respectively. From the EIS results, the coatings with tetrasiloxane acrylate and di-acrylate did not show any decrease in impedance or phase angle, even after 50 days' exposure to 0.1 M NaCl electrolyte, whereas the conventional acrylate coatings started to fail after only 24 h. A hybrid coating containing the amine-quinone functional group exhibited excellent corrosion protection properties with 4-5H pencil hardness.

  11. Investigations on neurotoxicity of chemical substances at the workplace. VII. Longitudinal study with determination of nerve conduction velocities in persons occupationally exposed to styrene

    Energy Technology Data Exchange (ETDEWEB)

    Triebig, G.; Schaller, K.H.; Valentin, H.

    1985-01-01

    The aim of this longitudinal study was to investigate whether long-term exposure to styrene is associated with functional disorders of the peripheral nervous system. Eleven workers (age: 24 to 54 years) of a polyester resin boat industry were studied neurophysiologically and biochemically in 1980 and 1983. The duration of styrene-exposure varied from 3 to 7 years, with a median of 4 years. The control group was comprised of 11 non-styrene-exposed workers of similar age. Air Monitoring with passive samplers was performed on different days for each person. The mean styrene concentrations were 114, 97 and 92 ppm respectively and therefore in the magnitude of the current MAK-value of 100 ppm in the Federal Republic of Germany (FRG). For Biological Monitoring styrene in blood (S-B) and mandelic acid (MA) as well as phenylglyoxylic-acid (PGA) in urine were determined in post-shift samples. The median values for MA at four different sampling times were 816, 1660, 1101 and 1224 mg/g creatinine and for PGA 200, 273, 342 and 336 mg/g creatinine respectively. These levels were below the current Biologischer Arbeitsstoff Toleranzwert (BAT-Wert) for MA (2000 mg/l) and MA + PGA (2500 mg/l). The S-B concentrations ranged from 0.05 mg/l to 3.26 mg/l, with mean values of 0.92 and 0.70 mg/l. The nerve conduction velocities (NCV) of motor and sensory nerve fibers (N. ulnaris and/or N. medianus) showed no significant differences between styrene-exposed workers and age-matched control persons. There were no hints of dose-effect-relationships by correlation analyses. Furthermore the follow-up determination revealed no significant changes regarding NCV.

  12. Proton conducting sulphonated fluorinated poly(styrene) crosslinked electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Soules, A.; Ameduri, B.; Boutevin, B.; David, G. [Institut Charles Gerhardt UMR CNRS 5253 Equipe, Ingenierie et Architectures Macromoleculaires,' ' Ecole Nationale Superieure de Chimie de Montpellier, 8 rue de l' Ecole Normale, 34296 Montpellier, Cedex 05 (France); Perrin, R. [CEA Le Ripault Departement des Materiaux, DMAT/SCMF/LSTP, BP16 - 37260 Monts (France); Gebel, G. [Structure et Proprietes des Architectures Moleculaires UMR 5819 (CEA-CNRS-UJF), INAC, SPrAM, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France)

    2011-10-15

    Potential membranes for polymer electrolyte membrane fuel cell based on crosslinked sulphonated fluorinated polystyrenes (PS) were synthesised in two steps. First, azide-telechelic polystyrene was obtained by iodine transfer polymerisation of styrene in the presence of 1,6-diiodoperfluorohexane followed by azido chain-end functionalisation. Then azide-telechelic polystyrene was efficiently crosslinked with 1,10-diazido-1H,1H,2H,2H,9H,9H,10H,10H-perfluorodecane under UV irradiation. After 45 min only, almost completion of azide crosslinking could be achieved, resulting in crosslinked membranes with insoluble fractions higher than 95%. The sulphonation of the crosslinked membranes afforded ionic exchange capacities (IECs) ranging from 2.2 to 3.2 meq g{sup -1}. The hydration number was shown to be very high (from 30 to 75), depending on both the content of perfluorodecane and of sulphonic acid groups. The morphology of the membranes, assessed by small-angle X-ray scattering, was found to be a lamellar-type structure with two types of ionic domains. For the membrane that exhibited an IEC value of 2.2 meq.g{sup -1}, proton conductivity was in the same range as that of Nafion {sup registered} (120-135 mS.cm{sup -1}), whereas the membrane IEC value of 3.2 meq.g{sup -1} showed a proton conductivity higher than that of Nafion {sup registered} in liquid water from 25 to 80 C, though a high water uptake. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. New styrene-b-isobutylene-b-styrene (SIBS) glaucoma drainage implant

    Science.gov (United States)

    Orozco, Marcia A.; Acosta, Ana C.; Espana, Edgar M.; Pinchuk, Leonard; Weber, Bruce; Davis, Stewart; Arrieta, Esdras; Dubovy, Sander; Fantes, Francisco; Aly, Mohamed; Zhou, Yonghua; Parel, Jean-Marie

    2006-02-01

    Purpose: To design and test the Miami-InnFocus Drainage Implant (MiDi) as a glaucoma shunt that is biocompatible, flexible, and significantly smaller than existing commercial implants in order to prevent postoperative hypotony, inflammation, scarring, erosion, and extrusion. Methods: A new biomaterial composed of styrene-b-isobutylene-b-styrene (SIBS) was used in a novel design for a glaucoma drainage implant. The implant consists of a tube 11mm long with an inner diameter of 70, 100, and 150 μm and outer diameter of 250 μm with a 1mm2 tab located 4.5mm from the proximal tip to prevent migration. The device was implanted in 15 New Zealand White rabbits for biocompatibility and efficacy testing. A similarly designed implant made of polydimethylsiloxane was implanted in 6 other animals as a pseudo-control. Typical GDI implantation technique was modified for this device. The proximal end of the new SIBS implant was inserted 2mm into the anterior chamber and the distal end placed in a subconjunctival space created by the surgeon. Biocompatibility of the device was studied by slit-lamp follow-up and intraocular pressure (IOP) measurements recorded periodically. Results: Biocompatibility of the MiDi was excellent. A low and diffuse bleb was observed with these devices. All SIBS tubes were patent 9 months after insertion. Immunostaining demonstrated non-continuous deposition of collagen with virtually no encapsulation. No macrophages or myofibroblast were visible around the SIBS polymer which was found more bioinert than the control PDMS. Conclusion: This newly designed glaucoma implant is clinically biocompatible in the rabbit model and maintained 100% patency at 9 months.

  14. Oxidation of styrene to benzaldehyde/benzoic acid

    Indian Academy of Sciences (India)

    selectivity.11Due to the availability of dual oxidation states of metal ion, it offers the catalytic behaviour towards oxidation of alcohols and olefins resulting in aldehydes or ketones. Such properties are tuned by changing the counter cation of the polyoxoanions, for example, Co3[Si2W12O40] is a good catalyst in oxida-.

  15. Conceptual process design of extractive distillation processes for ethylbenzene/styrene separation

    NARCIS (Netherlands)

    Jongmans, Mark; Hermens, E.; Raijmakers, M.; Maassen, J.I.W.; Schuur, Boelo; de Haan, A.B.

    2012-01-01

    In the current styrene production process the distillation of the close-boiling ethylbenzene/styrene mixture to obtain an ethylbenzene impurity level of 100 ppm in styrene accounts for 75–80% of the energy requirements. The future target is to reach a level of 1–10 ppm, which will increase the

  16. 78 FR 20032 - Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-04-03

    ... AGENCY 40 CFR Part 180 Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of styrene-ethylene-propylene block copolymer (CAS Reg... permissible level for residues of styrene-ethylene-propylene block copolymer on food or feed commodities...

  17. Controlled Functionalization of Olefin/styrene Copolymers through Free Radical Processes

    NARCIS (Netherlands)

    Passaglia, Elisa; Aglietto, Mauro; Ciardelli, Francesco; Picchioni, Francesco

    2000-01-01

    The functionalization of styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS) and styrene-co-butadiene (SBR) random copolymer by free radical processes is presented. SEBS was functionalized in the melt with diethyl maleate (DEM) and dicumyl peroxide (DCP) as initiator. The

  18. Side chain alkylation of toluene with methanol over basic zeolites - novel production route towards styrene?

    NARCIS (Netherlands)

    Rep, M.; Rep, M.

    2002-01-01

    Styrene is an important monomer for the production of different types of (co-) polymers that are used in, e.g., toys, medical devices, food packaging, paper coatings etc. Styrene is produced with several different industrial processes. In 1998, the production of styrene monomer was approximately 21

  19. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate and...

  20. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/styrene copoly-mer. 177.1040 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1040 Acrylonitrile/styrene copoly-mer. Acrylonitrile/styrene copolymers identified in this section may be safely used as a component...