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Sample records for 2-dimethylamino ethyl methacrylate

  1. Synthesis, Thermal Properties, and Thermoresponsive Behaviors of Cyclic Poly(2-(dimethylamino)ethyl Methacrylate)s.

    PubMed

    An, Xiaonan; Tang, Qingquan; Zhu, Wen; Zhang, Ke; Zhao, Youliang

    2016-06-01

    This study aims at physicochemical properties of thermo- and pH/CO2 -responsive cyclic homopolymers. Three examples of cyclic poly(2-(dimethylamino)ethyl methacrylate)s (PDMAs) are synthesized by combining the reversible addition-fragmentation chain transfer process and the Diels-Alder ring-closure reaction. After cyclization, the glass transition temperature significantly increases (ΔTg = 51.8-59.7 °C) due to the different configurational entropy and end groups, and the maximum decomposition temperature to lose the pendent groups is drastically decreased from 309 to 278 °C. Effects of polymerization degree, polymer concentration, additive of NaCl, and pH/CO2 on lower critical solution temperature behaviors of PDMA aqueous solutions are investigated. The cloud points (Tc ) of ring PDMAs are usually higher than their linear precursors, and the ΔTc values obtained under a fixed condition can reach up to 20.7 °C, revealing the crucial role of the topology effect. This study paves the way for unique properties and applications of smart cyclic polymers and their derivatives. PMID:27126247

  2. Carboxymethyl cellulose-g-poly(2-(dimethylamino) ethyl methacrylate) hydrogel as adsorbent for dye removal.

    PubMed

    Salama, Ahmed; Shukry, Nadia; El-Sakhawy, Mohamed

    2015-02-01

    A novel adsorbent was prepared via crosslinking graft copolymerization of 2-(dimethylamino) ethyl methacrylate (DMAEMA) onto carboxymethyl cellulose (CMC) backbone. Ethylene glycol dimethacrylate and potassium persulphate were used as crosslinker and initiator, respectively. CMC-g-PDMAEMA hydrogel was used to remove methyl orange (MO) from aqueous solutions. The adsorption kinetics and isotherms were found to follow Pseudo-second-order kinetic model and Langmuir model, respectively. The high maximum adsorption capacity (1825 mg/g) implied that CMC-g-PDMAEMA can be used as promising adsorbent for the synthetic dyes removal from wastewater. PMID:25450049

  3. Semiconductor nanoparticles in poly((2-dimethylamino)ethyl methacrylate-co-acrylic acid) co-polymers

    NASA Astrophysics Data System (ADS)

    Trandafilović, L. V.; Bibić, N.; Georges, M. K.; Blanuša, J.; Radhakrishnan, T.; Djoković, V.

    2013-11-01

    Nanostructured cadmium selenide (CdSe) and lead sulfide (PbS) semiconductors were prepared in a poly(2-(dimethylamino)ethyl methacrylate-co-acrylic acid) matrix. The obtained nanoparticles were characterized by using optical and structural methods. Co-polymers were synthesized in two different molar ratios of pDMAEMA:acrylic acid monomer units (1:2, 1:1). Transmission electron microscopy analysis confirmed the presence of nano-sized CdSe and PbS particles. In the case of CdSe, a shift of the onset of the optical absorption toward lower wavelengths was observed. X-ray diffraction analysis revealed that both CdSe and PbS nanoparticles have cubic crystal structure.

  4. Stimuli-responsive spherical brushes based on D-galactopyranose and 2-(dimethylamino)ethyl methacrylate.

    PubMed

    Arslan, Hülya; Pfaff, André; Lu, Yan; Stepanek, Petr; Müller, Axel H E

    2014-01-01

    Stimuli-responsive spherical brushes composed of 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (MAIGal) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) are prepared via atom transfer radical polymerization (ATRP) using cross-linked polystyrene nanoparticles covered with a thin layer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) as ATRP initiator by the "grafting from" approach. The stimuli-responsive behavior of the deprotected spherical PMAGal-b-PDMAEMA block copolymer brushes is investigated by dynamic light scattering and cryogenic transmission electron microscopy. A brush with arms containing 160 MAGal and 170 DMAEMA monomer units shows a significant contraction of the hydrodynamic radius from 20 to 70 °C at pH = 8 with a cloud point at ≈40 °C, whereas no LCST is detected at pH = 6 and 7 due to the protonation of the DMAEMA units. Aggregates occur at low temperatures and pH 8 due to intermolecular interactions between the chains of different brushes, which disappear above LCST, when the PDMAEMA chains fold back to the core of the brushes, exposing the glycopolymer chains to the outside. PMID:24106068

  5. Dual responsive pickering emulsion stabilized by poly[2-(dimethylamino)ethyl methacrylate] grafted cellulose nanocrystals.

    PubMed

    Tang, Juntao; Lee, Micky Fu Xiang; Zhang, Wei; Zhao, Boxin; Berry, Richard M; Tam, Kam C

    2014-08-11

    A weak polyelectrolyte, poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA), was grafted onto the surface of cellulose nanocrystals via free radical polymerization. The resultant suspension of PDMAEMA-grafted-cellulose nanocrystals (PDMAEMA-g-CNC) possessed pH-responsive properties. The grafting was confirmed by FTIR, potentiometric titration, elementary analysis, and thermogravimetric analysis (TGA); the surface and interfacial properties of the modified particles were characterized by surface tensiometer. Compared to pristine cellulose nanocrystals, modified CNC significantly reduced the surface and interfacial tensions. Stable heptane-in-water and toluene-in-water emulsions were prepared with PDMAEMA-g-CNC. Various factors, such as polarity of solvents, concentration of particles, electrolytes, and pH, on the properties of the emulsions were investigated. Using Nile Red as a florescence probe, the stability of the emulsions as a function of pH and temperature was elucidated. It was deduced that PDMAEMA chains promoted the stability of emulsion droplets and their chain conformation varied with pH and temperature to trigger the emulsification and demulsification of oil droplets. Interestingly, for heptane system, the macroscopic colors varied depending on the pH condition, while the color of the toluene system remained the same. Reversible emulsion systems that responded to pH were observed and a thermoresponsive Pickering emulsion system was demonstrated. PMID:24983405

  6. A highly effective gene delivery vector--hyperbranched poly(2-(dimethylamino)ethyl methacrylate) from in situ deactivation enhanced ATRP.

    PubMed

    Newland, Ben; Tai, Hongyun; Zheng, Yu; Velasco, Diego; Di Luca, Andrea; Howdle, Steven M; Alexander, Cameron; Wang, Wenxin; Pandit, Abhay

    2010-07-14

    A hyperbranched 2-(dimethylamino)ethyl methacrylate (DMAEMA) based polymer has been synthesised by a one-pot in situ deactivation enhanced atom transfer radical polymerisation (DE-ATRP); it exhibits much higher transfection ability than linear poly(DMAEMA) and is comparable to the well known branched poly(ethylene imine) (PEI) and the SuperFect dendrimer but with lower cytotoxicity. PMID:20514386

  7. Novel cationic triblock copolymer of poly[2-(dimethylamino)ethyl methacrylate]-block-poly(β-amino ester)-block-poly[2-(dimethylamino)ethyl methacrylate]: a promising non-viral gene delivery system.

    PubMed

    Cordeiro, Rosemeyre A; Farinha, Dina; Rocha, Nuno; Serra, Arménio C; Faneca, Henrique; Coelho, Jorge F J

    2015-02-01

    This manuscript reports the synthesis of a new cationic block copolymer based on poly[2-(dimethylamino)ethyl methacrylate] and poly(β-amino ester) from different polymerization strategies. For the first time, it is proposed a triblock copolymer based only on cationic segments, aiming a high biocompatibility, enhanced buffering capacity and stimuli-responsive character in a single structure. The new block copolymer successfully condensed the plasmid DNA into nanosized polyplexes. The polyplexes were tested in two different cell lines revealing ∼4-fold and ∼6-fold (in HeLa cells), and ∼11-fold (in COS-7 cells) higher transgene expression than branched PEI and TurboFect™, respectively. These results show that this new block copolymer is a promising candidate to be used as a polymeric non-viral vector. PMID:25399846

  8. GDNF Gene Delivery via a 2-(Dimethylamino)ethyl Methacrylate Based Cyclized Knot Polymer for Neuronal Cell Applications

    PubMed Central

    2013-01-01

    Nonviral genetic therapeutic intervention strategies for neurological disorders hold great promise, but a lack of vector efficacy, coupled with vector toxicity, continue to hinder progress. Here we report the application of a newly developed class of polymer, distinctly different from conventional branched polymers, as a transfection agent for the delivery of glial cell line derived neurotrophic factor (GDNF) encoding gene. This new 2-(dimethylamino)ethyl methacrylate (DMAEMA) based cyclized knot polymer was studied for neuronal cell transfection applications, in comparison to branched polyethyleneimine (PEI). While showing a similar transfection profile over multiple cell types, the cyclized knot polymer showed far lower toxicity. In addition, transfection of Neu7 astrocytes with the GDNF encoding gene was able to cause neurite outgrowth when cocultured with dorsal root ganglia (DRGs). The cyclized knot polymer assessed here (PD-E 8%PEG), synthesized via a simple one-pot reaction, was shown to have great potential for neuronal gene therapy applications. PMID:23391146

  9. RAFT dispersion polymerization of 3-phenylpropyl methacrylate with poly[2-(dimethylamino)ethyl methacrylate] macro-CTAs in ethanol and associated thermoreversible polymorphism.

    PubMed

    Pei, Yiwen; Dharsana, Nadia C; van Hensbergen, Johannes A; Burford, Robert P; Roth, Peter J; Lowe, Andrew B

    2014-08-21

    The direct synthesis of methacrylic-based soft polymeric nanoparticles via reversible addition-fragmentation chain transfer dispersion polymerization (RAFTDP) is described. The use of poly[2-(dimethylamino)ethyl methacrylate]s, of varying average degree of polymerization (X¯n), as the stabilizing blocks for the RAFTDP of 3-phenylpropyl methacrylate (PPMA) in ethanol at 70 °C, at various total solids contents, yielded the full spectrum of self-assembled nanoparticles (spherical and worm aggregates and polymersomes). We also demonstrate that nanoparticle morphology can be tuned simply by controlling temperature. This is especially evident in the case of worm aggregates undergoing a thermoreversible transition to spherical species - a process that is accompanied by a macroscopic degelation-gelation process. PMID:24975501

  10. Characterization of complexation of poly (N-isopropylacrylamide-co-2-(dimethylamino) ethyl methacrylate) thermoresponsive cationic nanogels with salmon sperm DNA

    PubMed Central

    Moselhy, Jim; Vira, Tasnim; Liu, Fei-Fei; Wu, Xiao Yu

    2009-01-01

    Thermoresponsive cationic nanogel (TCNG) networks based on N-isopropylacrylamide (NIPAM), 2-(dimethylamino)ethyl methacrylate (DMAEMA), and quaternary alkyl ammonium halide salts of DMAEMA (DMAEMAQ) were synthesized by dispersion polymerization technique. The thermoresponsive properties of TCNGs and TCNG-salmon sperm DNA (sasDNA) polyplexes were characterized in aqueous media of various pH and ionic strength. P[NIPAM] and P[NIPAM/DMAEMA] TCNGs exhibited sharp volume phase transition (VPT) in water at critical temperatures (Tc) of 32 °C and 36 °C, respectively. Quaternized P[NIPAM/DMAEMAQ] TCNGs did not undergo sharp VPT up to 50 °C. The VPT of uncomplexed TCNGs were sensitive to the ionic composition and ionic strength of salts in solution, but were insensitive to pH in the range 5.0 to 7.4. The VPT of P[NIPAM/DMAEMAQ]/sasDNA diminished in magnitude with increasing Wp/Wd suggesting greater compaction of the polyplexes. The distinct phase-transition properties of P[NIPAM/DMAEMA]/sasDNA and P[NIPAM/DMAEMAQ]/sasDNA polyplexes were attributed to the condensing capability of polycations and to differences in the spatial distribution of structural charges in quaternized and nonquaternized networks. The findings demonstrate that stable TCNGs can be prepared with controllable responsive properties determined by the nature of the cationic charge incorporated and may have potential as vehicles for DNA delivery. PMID:19774114

  11. Study the friction behaviour of poly[2-(dimethylamino)ethyl methacrylate] brush with AFM probes in contact mechanics

    NASA Astrophysics Data System (ADS)

    Raftari, Maryam; Zhang, Zhenyu; Leggett, Graham J.; Geoghegan, Mark

    2011-10-01

    We have studied the frictional behaviour of grafted poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) films using friction force microscopy (FFM). The films were prepared on native oxide-terminated silicon substrates using the technique of atom transfer radical polymerization (ATRP). We show that single asperity contact mechanics (Johnson-Kendall-Roberts(JKR) and Derjaguin-Muller-Toporov(DMT)) as well as a linear (Amontons) relation between applied load and frictional load depending on the pH of the FFM probe. Measurements were made using functionalized and unfunctionalized silicon nitride triangular probes. Functionalized probes included gold-coated probes, and ones coated with a self-assembled monolayer of dodecanethiol (DDT). The frictional behaviour between PDMAEMA and all tips immersed in pH from 3 to 11 are corresponded to the DMT or JKR model and are linear in pH=1, 2, and 12. These results show that contact mechanics of polyelectrolytes in water is complex and strongly dependent on the environmental pH.

  12. Synthesis and self-assembly of terpyridine end-capped poly(N-isopropylacrylamide)-block-poly(2-(dimethylamino)ethyl methacrylate) diblock copolymers.

    PubMed

    Brassinne, Jérémy; Poggi, Elio; Fustin, Charles-André; Gohy, Jean-François

    2015-04-01

    At the basis of smart self-assembled materials are lying small building blocks that can hierarchically assemble in response to stimuli, e.g., temperature or chemical species. In this context, the synthesis of terpyridine end-capped poly(2-(dimethylamino)ethyl methacrylate)-block-poly(N-isopropylacrylamide) diblock copolymers via controlled radical copolymerization is reported here. The self-assembly of those copolymers is investigated in dilute aqueous solutions while varying temperature or adding transition metal ions, respectively, leading to the formation of micellar nanostructures or metallosupramolecular triblock copolymers. PMID:25491079

  13. Preparation and optical properties of CdS nanoparticles dispersed in poly(2-(dimethylamino)ethyl methacrylate-co-acrylic acid) co-polymers

    NASA Astrophysics Data System (ADS)

    Trandafilović, L. V.; Djoković, V.; Bibić, N.; Georges, M. K.; Radhakrishnan, T.

    2008-03-01

    CdS/poly(2-(dimethylamino)ethyl methacrylate-co-acrylic acid) nanocomposites were prepared and characterized using structural, optical and thermal methods. Co-polymers used as the matrices were synthesized by radical polymerization of the co-monomers in different mol ratios (1:1, 2:1 and 1:2, DMAEMA:acrylic acid). The presence of the nanostructured CdS was confirmed by TEM analysis as well as by the shift of the onset of the optical absorption towards lower wavelengths. XRD spectra showed the cubic crystal phase of the obtained CdS nanoparticles. TGA measurements revealed improved thermal stability of the nanocomposite with respect to pure co-polymer matrix.

  14. Preparation of complex nano-particles based on alginic acid/poly[(2-dimethylamino) ethyl methacrylate] and a drug vehicle for doxorubicin release controlled by ionic strength.

    PubMed

    Cai, Hong; Ni, Caihua; Zhang, Liping

    2012-01-23

    Monodispersed complex nano-particles were synthesized simply by mixing alginic acid (ALG-H) with poly[(2-dimethylamino) ethyl methacrylate] (PDEMA) in pure water without any surfactants or additives. The structure and properties of the nano-particles were extensively studied. The surface charges and average sizes of the nano-particles were varied with the composition of ALG-H and PDEMA. The nano-particles were formed through electrostatic attraction force, and they were very stable in pure water, but dissociated in salt solutions. An anticancer drug (doxorubicin) was loaded in the nano-particles and released in different saline solutions. The release profiles revealed that the drug release could be controlled by adjusting the pH and salt concentrations. The nano-particles displayed apparent advantages such as simple preparation process, low cost, free of organic solvents, size controllable, biodegradable and biocompatible. PMID:22079138

  15. Development of thermosensitive poly(n-isopropylacrylamide-co-((2-dimethylamino) ethyl methacrylate))-based nanoparticles for controlled drug release

    NASA Astrophysics Data System (ADS)

    Peng, Cheng-Liang; Tsai, Han-Min; Yang, Shu-Jyuan; Luo, Tsai-Yueh; Lin, Chia-Fu; Lin, Wuu-Jyh; Shieh, Ming-Jium

    2011-07-01

    Thermosensitive nanoparticles based on poly(N-isopropylacrylamide-co-((2-dimethylamino)ethylmethacrylate)) (poly(NIPA-co-DMAEMA)) copolymers were successfully fabricated by free radical polymerization. The lower critical solution temperature (LCST) of the synthesized nanoparticles was 41 °C and a temperature above which would cause the nanoparticles to undergo a volume phase transition from 140 to 100 nm, which could result in the expulsion of encapsulated drugs. Therefore, we used the poly(NIPA-co-DMAEMA) nanoparticles as a carrier for the controlled release of a hydrophobic anticancer agent, 7-ethyl-10-hydroxy-camptothecin (SN-38). The encapsulation efficiency and loading content of SN-38-loaded nanoparticles at an SN-38/poly(NIPA-co-DMAEMA) ratio of 1/10 (D/P = 1/10) were about 80% and 6.293%, respectively. Moreover, the release profile of SN-38-loaded nanoparticles revealed that the release rate at 42 °C (above LCST) was higher than that at 37 °C (below LCST), which demonstrated that the release of SN-38 could be controlled by increasing the temperature. The cytotoxicity of the SN-38-loaded poly(NIPA-co-DMAEMA) nanoparticles was investigated in human colon cancer cells (HT-29) to compare with the treatment of an anticancer drug, Irinotecan® (CPT-11). The antitumor efficacy evaluated in a C26 murine colon tumor model showed that the SN-38-loaded nanoparticles in combination with hyperthermia therapy efficiently suppressed tumor growth. The results indicate that these thermo-responsive nanoparticles are potential carriers for controlled drug delivery.

  16. Amphiphilic and biodegradable methoxy polyethylene glycol-block-(polycaprolactone-graft-poly(2-(dimethylamino)ethyl methacrylate)) as an effective gene carrier

    PubMed Central

    Guo, Shutao; Huang, Yuanyu; Wei, Tuo; Zhang, Wendi; Wang, Weiwei; Lin, Daoshu; Zhang, Xu; Kumar, Anil; Du, Quan; Xing, Jinfeng; Deng, Liandong; Liang, Zicai; Wang, Paul C.; Dong, Anjie; Liang, Xing-Jie

    2011-01-01

    A group of amphiphilic cationic polymers, methoxy polyethylene glycol-block-(polycaprolactone-graft-poly(2-(dimethylamino)ethyl methacrylate)) (PECD), were synthesized by combining ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) methods to form nanoparticles (NPs). The structures of these amphiphilic cationic polymers were characterized by 1H NMR measurement. The PECD NPs have hydrophobic cores covered with hydrophilic PEG and cationic PDMAEMA chains. These self-assembly nanoparticles were characterized by dynamic light scattering (DLS) technique. PECD NPs can effectively condense DNA to form compact complexes of the size 65–160 nm suitable for gene delivery. The in vitro gene transfection studies of HeLa and HepG2 cells show that PECD NPs have better transfection efficiency compared to polyethylenimine (PEI) and Lipofectamine 2000 at low dose (N/P = 5). The cytotoxicity result shows that PECD NPs/DNA complexes at the optimal N/P ratio for transfection have comparable toxicity with PEI and Lipofectamine. These results indicate that PECD NPs have a great potential to be used as efficient polymeric carriers for gene transfection. PMID:20970186

  17. Dynamics of tetrahydrofuran as minority component in a mixture with poly(2-(dimethylamino)ethyl methacrylate): A neutron scattering and dielectric spectroscopy investigation

    SciTech Connect

    Goracci, G. Arbe, A.; Lohstroh, W.; Su, Y.; Colmenero, J.

    2015-09-07

    We have investigated a mixture of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and tetrahydrofuran (THF) (70 wt. % PDMAEMA/30 wt. % THF) by combining dielectric spectroscopy and quasielastic neutron scattering (QENS) on a labelled sample, focusing on the dynamics of the THF molecules. Two independent processes have been identified. The “fast” one has been qualified as due to an internal motion of the THF ring leading to hydrogen displacements of about 3 Å with rather broadly distributed activation energies. The “slow” process is characterized by an Arrhenius-like temperature dependence of the characteristic time which persists over more than 9 orders of magnitude in time. The QENS results evidence the confined nature of this process, determining a size of about 8 Å for the volume within which THF hydrogens’ motions are restricted. In a complementary way, we have also investigated the structural features of the sample. This study suggests that THF molecules are well dispersed among side-groups nano-domains in the polymer matrix, ruling out a significant presence of clusters of solvent. Such a good dispersion, together with a rich mobility of the local environment, would prevent cooperativity effects to develop for the structural relaxation of solvent molecules, frustrating thereby the emergence of Vogel-Fulcher-like behavior, at least in the whole temperature interval investigated.

  18. Temperature-induced emission enhancement of star conjugated copolymers with poly(2-(dimethylamino)ethyl methacrylate) coronas for detection of bacteria.

    PubMed

    Qiu, Feng; Wang, Dali; Wang, Ruibin; Huan, Xiuying; Tong, Gangsheng; Zhu, Qi; Yan, Deyue; Zhu, Xinyuan

    2013-05-13

    A facile strategy for temperature-induced emission enhancement of star conjugated copolymers has been developed for biodetection. The star copolymers (HCP-star-PDMAEMAs) with different poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) chain lengths were synthesized from the hyperbranched conjugated polymer (HCP) macroinitiator by atom transfer radical polymerization (ATRP). The star conjugated copolymers exhibited interesting thermoresponsive phase transitions with adjustable lower critical solution temperature (LCST) depending on the pH of copolymer solution. Above the LCST, the emission of HCP-star-PDMAEMAs was enhanced greatly through restriction of intermolecular aggregation of conjugated polymer cores by the collapse of PDMAEMA arms. By changing the PDMAEMA length, the emission performance of HCP-star-PDMAEMAs could be readily adjusted. Correspondingly, this temperature-dependent emission enhancement of HCP-star-PDMAEMAs was successfully applied in the highly sensitive detection of bacteria. Due to the existence of a hyperbranched conjugated core and many thermo-responsive PDMAEMA arms, the detection limit of E. coli could reach 10(2) cfu mL(-1). PMID:23560391

  19. Synthesis of a novel supermagnetic iron oxide nanocomposite hydrogel based on graft copolymerization of poly((2-dimethylamino)ethyl methacrylate) onto salep for controlled release of drug.

    PubMed

    Bardajee, Ghasem Rezanejade; Hooshyar, Zari; Asli, Maryam Jahanbakhsh; Shahidi, Fatemeh Emamjome; Dianatnejad, Nastaran

    2014-03-01

    In this research, a novel supermagnetic iron oxide nanocomposite hydrogel was prepared using simultaneous in situ formation of iron oxide nanoparticles (IONs) and three-dimensional cross-linked polymer networks based on graft copolymerization of poly((2-dimethylamino)ethyl methacrylate) (PDMA) onto salep (PDMA-g-salep). The prepared ION-PDMA-g-salep hydrogel was systematically characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDAX), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). In addition, the ION-PDMA-g-salep hydrogel exhibits favorable swelling properties that are sensitive to temperature, pH, and external magnetic field (EMF). The drug release behavior of the prepared hydrogel under EMF, different temperatures and pHs was also studied for the evaluation of the release mechanism and determination of diffusion coefficients. Finally, the antibacterial activity and cytotoxicity studies of the prepared hydrogel were examined. These results suggested that the ION-PDMA-g-salep hydrogel could be a promising candidate for biological dressing applications. PMID:24433913

  20. Dynamics of tetrahydrofuran as minority component in a mixture with poly(2-(dimethylamino)ethyl methacrylate): A neutron scattering and dielectric spectroscopy investigation

    NASA Astrophysics Data System (ADS)

    Goracci, G.; Arbe, A.; Alegría, A.; Lohstroh, W.; Su, Y.; Colmenero, J.

    2015-09-01

    We have investigated a mixture of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and tetrahydrofuran (THF) (70 wt. % PDMAEMA/30 wt. % THF) by combining dielectric spectroscopy and quasielastic neutron scattering (QENS) on a labelled sample, focusing on the dynamics of the THF molecules. Two independent processes have been identified. The "fast" one has been qualified as due to an internal motion of the THF ring leading to hydrogen displacements of about 3 Å with rather broadly distributed activation energies. The "slow" process is characterized by an Arrhenius-like temperature dependence of the characteristic time which persists over more than 9 orders of magnitude in time. The QENS results evidence the confined nature of this process, determining a size of about 8 Å for the volume within which THF hydrogens' motions are restricted. In a complementary way, we have also investigated the structural features of the sample. This study suggests that THF molecules are well dispersed among side-groups nano-domains in the polymer matrix, ruling out a significant presence of clusters of solvent. Such a good dispersion, together with a rich mobility of the local environment, would prevent cooperativity effects to develop for the structural relaxation of solvent molecules, frustrating thereby the emergence of Vogel-Fulcher-like behavior, at least in the whole temperature interval investigated.

  1. Polyelectrolyte complexes of poly[(2-dimethylamino) ethyl methacrylate]/chondroitin sulfate obtained at different pHs: I. Preparation, characterization, cytotoxicity and controlled release of chondroitin sulfate.

    PubMed

    Bonkovoski, Letícia C; Martins, Alessandro F; Bellettini, Ismael C; Garcia, Francielle P; Nakamura, Celso V; Rubira, Adley F; Muniz, Edvani C

    2014-12-30

    For the first time, polyelectrolyte complex based on poly[(2-dimethylamino) ethyl methacrylate] (PDMAEMA) and chondroitin sulfate (CS) was prepared. The properties of novel material and precursors were investigated by WAXS, FTIR, TGA, SEM and DLS analysis. The PDMAEMA/CS PECs presented hydrophilic-hydrophobic transition at pHs 6.0, 7.0 and 8.0 whereas the non-complexed PDMAEMA showed such a transition at pH 8.0 and not at pHs 6.0 and 7.0. Studies of CS release from PECs at pHs 6 and 8 confirmed that the samples possess the potential to release the CS in alkaline and not in acidic conditions. Since PECs are thermo-responsive due to the reduction of LCST caused by the increase in pH, the release of CS was dependent on temperature and pH factors. Cytotoxicity assays using healthy VERO cells showed that the complexation between CS and PDMAEMA increased the PECs' biocompatibility related to PDMAEMA. However, the biocompatibility depends on the amount of CS present in the PECs. PMID:25311176

  2. Amphiphilic and biodegradable methoxy polyethylene glycol-block-(polycaprolactone-graft-poly(2-(dimethylamino)ethyl methacrylate)) as an effective gene carrier.

    PubMed

    Guo, Shutao; Huang, Yuanyu; Wei, Tuo; Zhang, Wendi; Wang, Weiwei; Lin, Daoshu; Zhang, Xu; Kumar, Anil; Du, Quan; Xing, Jinfeng; Deng, Liandong; Liang, Zicai; Wang, Paul C; Dong, Anjie; Liang, Xing-Jie

    2011-01-01

    A group of amphiphilic cationic polymers, methoxy polyethylene glycol-block-(polycaprolactone-graft-poly(2-(dimethylamino)ethyl methacrylate)) (PECD), were synthesized by combining ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) methods to form nanoparticles (NPs). The structures of these amphiphilic cationic polymers were characterized by (1)H NMR measurement. The PECD NPs have hydrophobic cores covered with hydrophilic PEG and cationic PDMAEMA chains. These self-assembly nanoparticles were characterized by dynamic light scattering (DLS) technique. PECD NPs can effectively condense DNA to form compact complexes of the size 65-160 nm suitable for gene delivery. The in vitro gene transfection studies of HeLa and HepG2 cells show that PECD NPs have better transfection efficiency compared to polyethylenimine (PEI) and Lipofectamine 2000 at low dose (N/P = 5). The cytotoxicity result shows that PECD NPs/DNA complexes at the optimal N/P ratio for transfection have comparable toxicity with PEI and Lipofectamine. These results indicate that PECD NPs have a great potential to be used as efficient polymeric carriers for gene transfection. PMID:20970186

  3. Fabrication of flexible, transparent and conductive films from single-walled carbon nanotubes with high aspect ratio using poly((furfuryl methacrylate)-co-(2-(dimethylamino)ethyl methacrylate)) as a new polymeric dispersant

    NASA Astrophysics Data System (ADS)

    Lee, Taeheon; Kim, Byunghee; Kim, Sumin; Han, Jong Hun; Jeon, Heung Bae; Lee, Young Sil; Paik, Hyun-Jong

    2015-04-01

    We synthesized poly((furfuryl methacrylate)-co-(2-(dimethylamino)ethyl methacrylate)) (p(FMA-co-DMAEMA)) for the dispersion of single-walled carbon nanotubes (SWCNTs) while maintaining their high aspect ratios. The nanotubes' length and height were 2.0 μm and 2 nm, as determined by transmission electron microscopy and atomic force microscopy, respectively. Transparent conductive films (TCFs) were fabricated by individually dispersed long SWCNTs onto a flexible polyethylene terephthalate substrate. The sheet resistance (Rs) was 210 Ω □-1 with 81% transmittance at a wavelength of 550 nm. To reduce their Rs, the TCFs were treated with HNO3 and SOCl2. After treatment, the TCFs had an Rs of 85.75 Ω □-1 at a transmittance of 85%. The TCFs exhibited no appreciable change over 200 repeated bending cycles. Dispersing SWCNTs with this newly synthesized polymer is an effective way to fabricate a transparent, highly conductive and flexible film.

  4. Structure and component dynamics in binary mixtures of poly(2-(dimethylamino)ethyl methacrylate) with water and tetrahydrofuran: A diffraction, calorimetric, and dielectric spectroscopy study.

    PubMed

    Goracci, G; Arbe, A; Alegría, A; Su, Y; Gasser, U; Colmenero, J

    2016-04-21

    We have combined X-ray diffraction, neutron diffraction with polarization analysis, small angle neutron scattering,differential scanning calorimetry, and broad band dielectric spectroscopy to investigate the structure and dynamics of binary mixtures of poly(2-(dimethylamino)ethyl methacrylate) with either water or tetrahydrofuran (THF) at different concentrations. Aqueous mixtures are characterized by a highly heterogeneous structure where water clusters coexist with an underlying nano-segregation of main chains and side groups of the polymeric matrix. THF molecules are homogeneously distributed among the polymeric nano-domains for concentrations of one THF molecule/monomer or lower. A more heterogeneous situation is found for higher THF amounts, but without evidences for solvent clusters. In THF-mixtures, we observe a remarkable reduction of the glass-transition temperature which is enhanced with increasing amount of solvent but seems to reach saturation at high THF concentrations. Adding THF markedly reduces the activation energy of the polymer β-relaxation. The presence of THF molecules seemingly hinders a slow component of this process which is active in the dry state. The aqueous mixtures present a strikingly broad glass-transition feature, revealing a highly heterogeneous behavior in agreement with the structural study. Regarding the solvent dynamics, deep in the glassy state all data can be described by an Arrhenius temperature dependence with a rather similar activation energy. However, the values of the characteristic times are about three orders of magnitude smaller for THF than for water. Water dynamics display a crossover toward increasingly higher apparent activation energies in the region of the onset of the glass transition, supporting its interpretation as a consequence of the freezing of the structuralrelaxation of the surrounding matrix. The absence of such a crossover (at least in the wide dynamic window here accessed) in THF is attributed to

  5. PEGylated poly(2-(dimethylamino) ethyl methacrylate)/DNA polyplex micelles decorated with phage-displayed TGN peptide for brain-targeted gene delivery.

    PubMed

    Qian, Yong; Zha, Yuan; Feng, Bing; Pang, Zhiqing; Zhang, Bo; Sun, Xiyang; Ren, Jinfeng; Zhang, Chi; Shao, Xiayan; Zhang, Qizhi; Jiang, Xinguo

    2013-03-01

    Phage-displayed TGN peptide-decorated polymeric micelle-like polyplexes based on pegylated poly(2-(dimethylamino) ethyl methacrylate) (PEG-PDMAEMA) were prepared for efficient brain-targeted gene delivery. The diblock copolymers Methoxy-PEG-PDMAEMA and Maleimide-PEG-PDMAEMA were synthesized by the atom transfer radical polymerization method. The TGN ligand, a 12-amino acid peptide that could facilitate blood-brain barrier (BBB) targeting, was conjugated to the PEG terminus of the copolymer via a maleimide-mediated covalent binding procedure. TGN-PEG-PDMAEMA was complexed with plasmid DNA to yield polyplexes. The physiochemical properties of the polyplexes, such as morphology, particle size, zeta potential, cytotoxicity and DNA complex formation ability, were studied prior to the successful in vitro and in vivo transfection. The TGN-PEG-PDMAEMA/DNA polyplexes maintained their stable nano-size, were characterized by good condensation capacity and low toxicity and even provided higher cellular uptake than the unmodified polyplexes (PEG-PDMAEMA/DNA polyplexes). Confocal microscopy studies showed that the DNA of TGN-PEG-PDMAEMA/DNA polyplexes entered into the nuclei through the endosome/lysosome pathway. The transfection efficiency of TGN-modified polyplexes was higher than that of unmodified polyplexes both in vitro and in vivo. The results obtained from frozen sections indicated the widespread expression of an exogenous gene in the mouse brain after intravenous injection. Therefore, the results demonstrate that the TGN-decorated PEG-PDMAEMA developed in this study could be utilized as a potential vehicle for gene delivery to the brain. PMID:23245924

  6. Structure and component dynamics in binary mixtures of poly(2-(dimethylamino)ethyl methacrylate) with water and tetrahydrofuran: A diffraction, calorimetric, and dielectric spectroscopy study

    NASA Astrophysics Data System (ADS)

    Goracci, G.; Arbe, A.; Alegría, A.; Su, Y.; Gasser, U.; Colmenero, J.

    2016-04-01

    We have combined X-ray diffraction, neutron diffraction with polarization analysis, small angle neutron scattering, differential scanning calorimetry, and broad band dielectric spectroscopy to investigate the structure and dynamics of binary mixtures of poly(2-(dimethylamino)ethyl methacrylate) with either water or tetrahydrofuran (THF) at different concentrations. Aqueous mixtures are characterized by a highly heterogeneous structure where water clusters coexist with an underlying nano-segregation of main chains and side groups of the polymeric matrix. THF molecules are homogeneously distributed among the polymeric nano-domains for concentrations of one THF molecule/monomer or lower. A more heterogeneous situation is found for higher THF amounts, but without evidences for solvent clusters. In THF-mixtures, we observe a remarkable reduction of the glass-transition temperature which is enhanced with increasing amount of solvent but seems to reach saturation at high THF concentrations. Adding THF markedly reduces the activation energy of the polymer β-relaxation. The presence of THF molecules seemingly hinders a slow component of this process which is active in the dry state. The aqueous mixtures present a strikingly broad glass-transition feature, revealing a highly heterogeneous behavior in agreement with the structural study. Regarding the solvent dynamics, deep in the glassy state all data can be described by an Arrhenius temperature dependence with a rather similar activation energy. However, the values of the characteristic times are about three orders of magnitude smaller for THF than for water. Water dynamics display a crossover toward increasingly higher apparent activation energies in the region of the onset of the glass transition, supporting its interpretation as a consequence of the freezing of the structural relaxation of the surrounding matrix. The absence of such a crossover (at least in the wide dynamic window here accessed) in THF is attributed to

  7. GENOTOXICITY OF ACRYLIC ACID, METHYL ACRYLATE, ETHYL ACRYLATE, METHYL METHACRYLATE, AND ETHYL METHACRYLATE IN L5178Y MOUSE LYMPHOMA CELLS (JOURNAL VERSION)

    EPA Science Inventory

    A series of monomeric acrylate/methacrylate esters (methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate) as well as acrylic acid were examined for genotoxic activity in L5178Y mouse lymphoma cells without exogenous activation. All five compounds induced c...

  8. Growth of tantalum nitride film as a Cu diffusion barrier by plasma-enhanced atomic layer deposition from bis((2-(dimethylamino)ethyl)(methyl)amido)methyl(tert-butylimido)tantalum complex

    NASA Astrophysics Data System (ADS)

    Han, Jeong Hwan; Kim, Hyo Yeon; Lee, Sang Chan; Kim, Da Hye; Park, Bo Keun; Park, Jin-Seong; Jeon, Dong Ju; Chung, Taek-Mo; Kim, Chang Gyoun

    2016-01-01

    A new bis((2-(dimethylamino)ethyl)(methyl)amido)methyl(tert-butylimido)tantalum complex was synthesized for plasma-enhanced atomic layer deposition (PEALD) of tantalum nitride (TaN) film. Using the synthesized Ta compound, PEALD of TaN was conducted at growth temperatures of 150-250 °C in combination with NH3 plasma. The TaN PEALD showed a saturated growth rate of 0.062 nm/cycle and a high film density of 9.1-10.3 g/cm3 at 200-250 °C. Auger depth profiling revealed that the deposited TaN film contained low carbon and oxygen impurity levels of approximately 3-4%. N-rich amorphous TaN films were grown at all growth temperatures and showed highly resistive characteristic. The Cu barrier performance of the TaN film was evaluated by annealing of Cu/TaN (0-6 nm)/Si stacks at 400-800 °C, and excellent Cu diffusion barrier properties were observed even with ultrathin 2 nm-thick TaN film.

  9. A new mechanism of 6-((2-(dimethylamino)ethyl)amino)-3-hydroxy-7H-indeno(2,1-c)quinolin-7-one dihydrochloride (TAS-103) action discovered by target screening with drug-immobilized affinity beads.

    PubMed

    Yoshida, Makoto; Kabe, Yasuaki; Wada, Tadashi; Asai, Akira; Handa, Hiroshi

    2008-03-01

    6-((2-(Dimethylamino)ethyl)amino)-3-hydroxy-7H-indeno(2,1-c)-quinolin-7-one dihydrochloride (TAS-103) is a quinoline derivative that displays antitumor activity in murine and human tumor models. TAS-103 has been reported to be a potent topoisomerase II poison. However, other studies have indicated that cellular susceptibility to TAS-103 is not correlated with topoisomerase II expression. Because the direct target of TAS-103 remained unclear, we searched for a TAS-103 binding protein using high-performance affinity latex beads. We obtained a component of the signal recognition particle (SRP) as a TAS-103 binding protein. This component is a 54-kDa subunit (SRP54) of SRP, which mediates the proper delivery of secretory proteins in cells. We fractioned 293T cell lysates using gel-filtration chromatography and performed a coimmunoprecipitation assay using 293T cells expressing FLAG-tagged SRP54. The results revealed that TAS-103 disrupts SRP complex formation and reduces the amount of SRP14 and SRP19. TAS-103 treatment and RNAi-mediated knockdown of SRP54 or SRP14 promoted accumulation of the exogenously expressed chimeric protein interleukin-6-FLAG inside cells. In conclusion, we identified signal recognition particle as a target of TAS-103 by using affinity latex beads. This provides new insights into the mechanism underlying the effects of chemotherapies comprising TAS-103 and demonstrates the usefulness of the affinity beads. PMID:18089836

  10. Controlled Degradation of Poly(Ethyl Cyanoacrylate-Co-Methyl Methacrylate)(PECA-Co-PMMA) Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes a method for modifying poly(ethyl cyanoacrylate) in order to control the degradation and the stability as well as the glass transition temperatures. Copolymers of poly(ethyl cyanoacrylate-co-methyl methacrylate) (PECA-co-PMMA) with various compositions were synthesized by free ...

  11. Study of the miscibility of poly(styrene-co-4-vinylbenzoic acid) with poly(ethyl methacrylate) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] by inverse gas chromatography.

    PubMed

    Ourdani, Samia; Amrani, Farouk

    2002-09-01

    Poly(styrene) is immiscible with poly(ethyl methacrylate). The introduction of a small amount of 4-vinylbenzoic acid units along poly(styrene) chains (PS-VBA) enhanced its miscibility with poly(ethyl methacrylate) (PEMA) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] (PEMA-DAE), as observed from the appearance of a single composition dependent glass transition temperature for each binary system using inverse gas chromatography. The negative values of the apparent polymer-polymer interaction parameter, chi(23)app, determined with different families of molecular probes, for three blend compositions and over a range of temperature confirm quantitatively the miscibility of these blends. The chi(23)app values for PEMA(PS-VBA) and (PEMA-DAE)-(PS-VBA) blends are dependent of the chemical nature of the probes, the temperature and the blend composition. PMID:12385399

  12. Dispersion of luminescent nanoparticles in different derivatives of poly(ethyl methacrylate).

    PubMed

    Davion, B; Delhorbe, V; Péralta, S P; Goubard, F; Vidal, F

    2011-04-01

    Gd2O3:Tb(5%) nanoparticles were prepared via the polyol route and dispersed without any stabilizer in several ethyl methacrylate derivatives matrices such as poly(ethyl methacrylate), poly(2-methoxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate) (PHEMA). Nanocomposites were obtained via free-radical polymerization of methacrylic monomers with ethylene glycol dimethacrylate as crosslinker and colloidal solution of Gd2O3:Tb(5%) nanoparticles. Best results are obtained with PHEMA in which the dispersed Gd2O3:Tb(5%) nanoparticles are spherical with a mean diameter of 15 nm, as measured by TEM. The obtained solid Gd2O3:Tb(5%)/PHEMA nanocomposites are highly transparent (in the visible spectral range) and exhibit characteristic photoluminescence of Tb3+ 5D4-7F(J) (J = 6-3), with 5D4-7F5 strong green emission at 536 nm upon UV excitation. The nanoparticles and nanocomposites have been well characterized by high-resolution transmission electron microscope (TEM), UV/Vis transmission spectra, photoluminescence excitation, and emission spectra. PMID:21776688

  13. Flexural properties of ethyl or methyl methacrylate-UDMA blend polymers.

    PubMed

    Kanie, Takahito; Kadokawa, Akihiko; Arikawa, Hiroyuki; Fujii, Koichi; Ban, Seiji

    2010-10-01

    Light-curing polyethyl methacrylate (PEMA)-urethane dimethacrylate (UDMA) resins and polymethyl methacrylate (PMMA)-UDMA resins were prepared by two processes. For first step, PEMA or PMMA powders were fully dissolved in ethyl methacrylate (EMA) or methyl methacrylate (MMA) and then the PEMA-EMA/PMMA-MMA mixtures were mixed with UDMA. The flexural properties of cured PEMA-UDMA and PMMA-UDMA polymers were measured using two PEMA (Mw: 300,000-400,000 and 650,000-1,000,000) and three PMMA (Mw: 30,000-60,000, 350,000 and 650,000-1,000,000) powders with different molecular weight, four mixing ratios of PMMA-MMA, and three mixing ratios of PMMA-MMA mixture and UDMA oligomer. Polymers with PMMA(Mw: 350,000) MMA=25/50, and with PMMA(Mw: 350,000)-MMA/UDMA=1/2 and =1/1, showed no-fracture in a flexural test at 1 mm/min and flexural strength and flexural modulus showed no significant difference compared with those of commercially available heat- and self-curing acrylic resins (p>0.01). Within limitation of this investigation, methyl methacrylate-UDMA blend polymer of this composition is available for denture base resin. PMID:20733259

  14. Ferromagnetic resonance spectroscopy of carboxylated cobalt-containing nanocomposite ethyl methacrylate/acrylic acid copolymers

    NASA Astrophysics Data System (ADS)

    Voytsihovskaya, S. A.; Sokolov, M. E.; Panyushkin, V. T.; Gromov, P. Yu.; Shcherbina, A. A.; Matveev, V. V.

    2013-01-01

    We have used ferromagnetic resonance spectroscopy to study the effect of the concentration of cobalt nanoparticles (5-9 nm) incorporated into ethyl methacrylate/acrylic acid copolymers (monomer ratios 100:1 and 10:1) on the magnitude of the resonant field in ferromagnetic resonance and on the effective magnetization of thin-film samples of these nanocomposite polymer materials. The cobalt nanoparticles were obtained by thermolysis of Co2(CO)8 in 5% solutions of the indicated copolymers in toluene. From the solutions obtained, we prepared films of thickness 1 μm on aluminum substrates.

  15. Influence of spoliation in poly(2-hydroxy ethyl methacrylate) soft contact lens on its free volume and optical transparency.

    PubMed

    Deepa Urs, M V; Ranganathaiah, C

    2008-03-01

    The calcification in poly(2-hydroxy ethyl methacrylate) contact lens was investigated using positron annihilation spectroscopy (PLS). The two poly(2-hydroxy ethyl methacrylate) (PHEMA) lenses of different companies were calcified employing a simple mechanism of calcification in abiotic aqueous solutions. The calcium deposit was analyzed using energy dispersive X-ray spectroscopy (EDS). Calcified lenses showed decrease in ortho-positronium (o-Ps) lifetime and free volume hole size of the lens material suggesting diffusion of Ca2+ into these cavities. The change in optical property viz. refractive index of these calcified lenses were measured and correlated with positron results. To find a better correlation, a series of worn spoilt PHEMA lenses of the same power with mainly calcium deposits, were similarly characterized using PLS and refractive index. These results correlate well with the free volume of the material. For hydrophilic lenses this correlation is reported for the first time. PMID:17914610

  16. Novel Pickering emulsifiers based on pH-responsive poly(2-(diethylamino)ethyl methacrylate) latexes.

    PubMed

    Morse, A J; Armes, S P; Thompson, K L; Dupin, D; Fielding, L A; Mills, P; Swart, R

    2013-05-01

    The emulsion copolymerization of 2-(diethylamino)ethyl methacrylate (DEA) with a divinylbenzene cross-linker in the presence of monomethoxy-capped poly(ethylene glycol) methacrylate (PEGMA) at 70 °C afforded near-monodisperse, sterically stabilized PEGMA-PDEA latexes at 10% solids. Dynamic light scattering studies indicated intensity-average diameters of 190 to 240 nm for these latexes at pH 9. A latex-to-microgel transition occurred on lowering the solution pH to below the latex pKa of 6.9. When dilute HCl/KOH was used to adjust the aqueous pH, a systematic reduction in the cationic microgel hydrodynamic diameter of 80 nm was observed over ten pH cycles as a result of the gradual buildup of background salt. However, no such size reduction was observed when using CO2/N2 gases to regulate the aqueous pH because this protocol does not generate background salt. Thus, the latter approach offers better reversibility, albeit at the cost of slower response times. PEGMA-PDEA microgel does not stabilize Pickering emulsions when homogenized at pH 3 with n-dodecane, sunflower oil, isononyl isononanoate, or isopropyl myristate. In contrast, PEGMA-PDEA latex proved to be a ubiquitous Pickering emulsifier at pH 10, forming stable oil-in-water emulsions with each of these four model oils. Lowering the solution pH from 10 to 3 resulted in demulsification within seconds. This is because these pH-responsive particles undergo a latex-to-microgel transition, which leads to their interfacial desorption. Six successive demulsification/emulsification cycles were performed on these Pickering emulsions using HCl/KOH to adjust the solution pH. Demulsification could also be achieved by purging the emulsion solution with CO2 gas to lower the aqueous pH to 4.8. However, complete phase separation required CO2 purging for 4 h at 20 °C. A subsequent N2 purge raised the aqueous pH sufficiently to induce a microgel-to-latex transition, but rehomogenization did not produce a stable Pickering

  17. Amphiphilic Copolymers of Polyfluorene Methacrylates Exhibiting Tunable Emissions for Ink-Jet Printing.

    PubMed

    Deng, Chao; Ling, Jun

    2016-08-01

    Functionalized polyfluorene receives more and more attention due to its wide applications. Here, the syntheses of three novel polyfluorene-based methacrylate macromonomers exhibiting a vast flexibility for further applications are reported. Their emissions strongly depend on the end groups and thus the macromonomers provide blue, green, and red emissions simultaneously with the same excitation light of 365 nm. Their well-defined copolymers with 2-(dimethylamino) ethyl methacrylate via reversible addition-fragmentation chain transfer polymerization are investigated in detail. These copolymers exhibit high quantum yields in solid film (up to 0.8), and self-assemble into photoluminescent nanoparticles in aqueous solutions with pure blue, green, and red emissions. By simply mixing them, perfect white light emission with high quality is obtained. These aqueous nanoparticles solutions are ready for ink-jet printing to produce exquisite bright and colorful fluorescent pictures. PMID:27310485

  18. Graft copolymers of ethyl methacrylate on waxy maize starch derivatives as novel excipients for matrix tablets: physicochemical and technological characterisation.

    PubMed

    Marinich, J A; Ferrero, C; Jiménez-Castellanos, M R

    2009-05-01

    Nowadays, graft copolymers are being used as an interesting option when developing a direct compression excipient for controlled release matrix tablets. New graft copolymers of ethyl methacrylate (EMA) on waxy maize starch (MS) and hydroxypropylstarch (MHS) were synthesised by free radical polymerization and alternatively dried in a vacuum oven (OD) or freeze-dried (FD). This paper evaluates the performance of these new macromolecules and discusses the effect of the carbohydrate nature and drying process on their physicochemical and technological properties. Grafting of EMA on the carbohydrate backbone was confirmed by IR and NMR spectroscopy, and the grafting yields revealed that graft copolymers present mainly a hydrophobic character. The graft copolymerization also leads to more amorphous materials with larger particle size and lower apparent density and water content than carbohydrates (MS, MHS). All the products show a lack of flow, except MHSEMA derivatives. MSEMA copolymers underwent much plastic flow and less elastic recovery than MHSEMA copolymers. Concerning the effect of drying method, FD derivatives were characterised by higher plastic deformation and less elasticity than OD derivatives. Tablets obtained from graft copolymers showed higher crushing strength and disintegration time than tablets obtained from raw starches. This behaviour suggests that these copolymers could be used as excipients in matrix tablets obtained by direct compression and with a potential use in controlled release. PMID:19146956

  19. Surface Modification of Polypropylene Microporous Membrane by Atmospheric-Pressure Plasma Immobilization of N,N-dimethylamino Ethyl Methacrylate

    NASA Astrophysics Data System (ADS)

    Zhong, Shaofeng

    2010-10-01

    Surface modification of polypropylene microporous membrane (PPMM) was performed by atmospheric pressure dielectric barrier discharge plasma immobilization of N,N-dimethylamino ethyl methacrylate (DMAEMA). Structural and morphological changes on the membrane surface were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (FT-IR/ATR), X-ray photoelectron spectroscope (XPS) and field emission scanning electron microscopy (FE-SEM). Water contact angles of the membrane surfaces were also measured by the sessile drop method. Results reveal that both the plasma-treating conditions and the adsorbed DMAEMA amount have remarkable effects on the immobilization degree of DMAEMA. Peroxide determination by 1,1-diphenyl-2-picrvlhydrazyl (DPPH) method verifies the exsistence of radicals induced by plasma, which activize the immobilization reaction. Pure water contact angle on the membrane surface decreased with the increase of DMAEMA immobilization degree, which indicates an enhanced hydrophilicity for the modified membranes. The effects of immobilization degrees on pure water fluxes were also measured. It is shown that pure water fluxes first increased with immobilization degree and then decreased. Finally, permeation of bovine serum albumin (BSA) and lysozyme solution were measured to evaluate the antifouling property of the DMAEMA-modified membranes, from which it is shown that both hydrophilicity and electrostatic repulsion are beneficial for membrane antifouling.

  20. Efficient gene carriers composed of 2-hydroxypropyl-β-cyclodextrin, ethanolamine-functionalized poly(glycidyl methacrylate), and poly((2-dimethyl amino)ethyl methacrylate) by combination of ATRP and click chemistry.

    PubMed

    Zhu, Yun; Zheng, Xuefeng; Yu, Bingran; Yang, Wantai; Zhao, Nana; Xu, Fujian

    2014-08-01

    In this work, a simple one-step method is first employed to produce the bromoisobutyryl-terminated 2-hydroxypropyl-β-cyclodextrin (HPCD-Br). The pendant epoxy groups of poly(glycidyl methacrylate) block prepared via ATRP from HPCD-Br can be reacted with ethanolamine to produce HPCD-PGEA which exhibits much lower cytotoxicity and better gene transfection yield than polyethylenimine (25 kDa) in COS7 and HepG2 cell lines. Moreover, poly((2-dimethyl amino)ethyl methacrylate) blocks can be incorporated into low-molecular-weight HPCD-PGEA via "click" reaction to further enhance the gene transfection efficiency in HepG2 cell lines. PMID:24789347

  1. Molecular dynamics simulations of 2-(dimethylamino)ethanol (DMEA).

    PubMed

    Bringas, Guadalupe; Navarro-Santos, Pedro; López-Rendón, Roberto; López-Lemus, Jorge; Bresme, Fernando

    2015-04-16

    We develop a multipurpose force field to investigate the properties of the condensed phases of 2-(dimethylamino)ethanol (DMEA). We use ab initio computations at the HF/6-311++G(2d,2p) level to derive partial charges, obtain force constants, and compute the electrostatic potential of the DMEA. We find that the HF predictions for the dipole moment are in excellent agreement with the experimental result (2.6 D). The computations also show the strong preference of DMEA to form intramolecular hydrogen bonds between the hydrogen in the alcohol group and nitrogen. We have tested the accuracy of our force field by computing coexistence and interfacial properties as well as thermal conductivities in wide range of thermodynamic states. In all these instances we find excellent agreement with the available experimental data. We have further investigated the structure of the liquid by computing pair correlations. Our results indicate a clear preference for DMEA to form low-dimensional structures, such as linear and bifurcated chains, which are driven by the association of the DMEA molecules via the alcohol group. Overall, our force field provides a good basis to compute the bulk and interfacial properties of DMEA. PMID:25799889

  2. Phase separation kinetics and morphology induced by photopolymerization of 2-hydroxyehyl methacrylate (HEMA) in poly(ethyl acrylate)/HEMA mixtures

    NASA Astrophysics Data System (ADS)

    Van-Pham, Dan-Thuy; Tran-Cong-Miyata, Qui

    2013-03-01

    Morphology and phase separation kinetics induced by polymerization of 2-hydroxyethyl methacrylate (HEMA) in a HEMA/poly(ethyl acrylate) (PEA) mixture were observed by laser scanning confocal microscope in the presence of lucirin TPO used as an initiator. The results were analyzed by 2D-Fourier transform (2D-FFT). The photopolymerization is driven by irradiation with visible light λ = 405 nm. The mixture exhibits the Trommsdorff-Norrish effect which is responsible for a drastic increase in the reaction rate during the irradiation process. The concentration fluctuations and the increase in the viscosity of the medium play an important role in promoting the reaction yield. PHEMA droplets were found to develop in the rhodamine-B-labeled poly(ethyl acrylate) (PEA-Rh) continuous matrix. The characteristic length of the morphology increases with increasing irradiation intensity, revealing the tool to control the morphology by varying the light intensity.

  3. Effects of Grafting Density and Film Thickness on the Adhesion of Staphylococcus epidermidis to Poly(2-hydroxy ethyl methacrylate) and Poly(poly(ethylene glycol)methacrylate) Brushes.

    PubMed

    Ibanescu, Sorin-Alexandru; Nowakowska, Justyna; Khanna, Nina; Landmann, Regine; Klok, Harm-Anton

    2016-05-01

    Thin polymer films that prevent the adhesion of bacteria are of interest as coatings for the development of infection-resistant biomaterials. This study investigates the influence of grafting density and film thickness on the adhesion of Staphylococcus epidermidis to poly(poly(ethylene glycol)methacrylate) (PPEGMA) and poly(2-hydroxyethyl methacrylate) (PHEMA) brushes prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). These brushes are compared with poly(ethylene glycol) (PEG) brushes, which are obtained by grafting PEG onto an epoxide-modified substrate. Except for very low grafting densities (ρ = 1%), crystal violet staining experiments show that the PHEMA and PPEGMA brushes are equally effective as the PEG-modified surfaces in preventing S. epidermis adhesion and do not reveal any significant variations as a function of film thickness or grafting density. These results indicate that brushes generated by SI-ATRP are an attractive alternative to grafted-onto PEG films for the preparation of surface coatings that resist bacterial adhesion. PMID:26757483

  4. Fabrication and characterization of superparamagnetic and thermoresponsive hydrogels based on oleic-acid-coated Fe 3O 4 nanoparticles, hexa(ethylene glycol) methyl ether methacrylate and 2-(acetoacetoxy)ethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Papaphilippou, Petri C.; Pourgouris, Antonis; Marinica, Oana; Taculescu, Alina; Athanasopoulos, George I.; Vekas, Ladislau; Krasia-Christoforou, Theodora

    2011-03-01

    Stimuli-responsive hydrogel nanocomposites comprised of swollen polymer networks, in which magnetic nanoparticles are embedded, are a relatively new class of "smart" soft materials presenting a significant impact on various technological and biomedical applications. A novel approach for the fabrication of hydrogel nanocomposites exhibiting temperature- and magneto-responsive behavior involves the random copolymerization of hexa(ethylene glycol) methyl ether methacrylate (HEGMA, hydrophilic, thermoresponsive) and 2-(acetoacetoxy)ethyl methacrylate (AEMA, hydrophobic, metal-chelating) in the presence of preformed oleic-acid-coated magnetite nanoparticles (OA·Fe 3O 4). In total, two series of hydrogel nanocomposites have been prepared in two different solvent systems: ethyl acetate (series A) and tetrahydrofuran (series B). The degrees of swelling (DSs) of all conetworks were determined in organic and in aqueous media. The nanocrystalline phase adopted by the embedded magnetic nanoparticles was investigated by X-ray diffraction (XRD) spectroscopy. The obtained diffraction patterns indicated the presence of magnetite (Fe 3O 4). Deswelling kinetic studies that were carried out at ˜60 °C in water demonstrated the thermoresponsive properties of the hydrogel nanocomposites, attributed to the presence of the hexaethylene glycol side chains within the conetworks. Moreover, thermal gravimetric analysis (TGA) measurements showed that these materials exhibited superior thermal stability compared to the pristine hydrogels. Further to the characterization of compositional and thermal properties, the assessment of magnetic characteristics by vibrational sample magnetometry (VSM) disclosed superparamagnetic behavior. The tunable superparamagnetic behavior exhibited by these materials depending on the amount of magnetic nanoparticles incorporated within the networks combined with their thermoresponsive properties may allow for their future exploitation in the biomedical field.

  5. Poly(DL-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate): synthesis, characterization, micellization behavior in aqueous solutions, and encapsulation of the hydrophobic drug dipyridamole.

    PubMed

    Karanikolopoulos, Nikos; Zamurovic, Miljana; Pitsikalis, Marinos; Hadjichristidis, Nikos

    2010-02-01

    We synthesized a series of well-defined poly(dl-lactide)-b-poly(N,N-dimethylamino-2-ethyl methacrylate) (PDLLA-b-PDMAEMA) amphiphilic diblock copolymers by employing a three-step procedure: (a) ring-opening polymerization (ROP) of dl-lactide using n-decanol and stannous octoate, Sn(Oct)(2), as the initiating system, (b) reaction of the PDLLA hydroxyl end groups with bromoisobutyryl bromide, and (c) atom transfer radical polymerization, ATRP, of DMAEMA with the newly created bromoisobutyryl initiating site. The aggregation behavior of the prepared block copolymers was investigated by dynamic light scattering and zeta potential measurements at 25 degrees C in aqueous solutions of different pH values. The hydrophobic drug dipyridamole was efficiently incorporated into the copolymer aggregates in aqueous solutions of pH 7.40. High partition coefficient values were determined by fluorescence spectroscopy. PMID:20041661

  6. Deciphering Physical versus Chemical Contributions to the Ionic Conductivity of Functionalized Poly(methacrylate)-Based Ionogel Electrolytes.

    PubMed

    D'Angelo, Anthony J; Grimes, Jerren J; Panzer, Matthew J

    2015-11-25

    Polymer-supported ionic liquids (ionogels) are emergent, nonvolatile electrolytes for electrochemical energy storage applications. Here, chemical and physical interactions between the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI) and three different cross-linked polymer scaffolds with varying chemical functional groups have been investigated in ionogels fabricated via in situ UV-initiated radical polymerization of methyl methacrylate (MMA), 2,2,2-trifluoroethyl methacrylate (TFEMA), or 2-(dimethylamino)ethyl methacrylate (DMAEMA) and a small amount of the cross-linker pentaerythritol tetraacrylate. Experimental findings demonstrate that the chemical functionality of the polymer side groups can significantly affect the degree of ion dissociation within the ionic liquid component of the ionogel and that the fraction of dissociated ions is the dominant factor in determining relative ionic conductivity in these materials, rather than any large differences in ion diffusivity. The MMA-based polymer scaffold exhibits a stronger attractive interaction with EMI TFSI (as evidenced by a higher activation energy of ionic conductivity) compared to the TFEMA- and DMAEMA-based scaffolds, resulting in consistently lower ionic conductivity values for MMA-based ionogels. These results may offer guidance toward the rational selection of future polymer-ionic liquid pairings in order to maximize the fraction of dissociated ions, thereby yielding highly conductive ionogel electrolytes. PMID:26528868

  7. Coating process and early stage adhesion evaluation of poly(2-hydroxy-ethyl-methacrylate) hydrogel coating of 316L steel surface for stent applications.

    PubMed

    Indolfi, Laura; Causa, Filippo; Netti, Paolo Antonio

    2009-07-01

    In this study, a spray-coating method has been set up with the aim to control the coating of poly(2-hydroxy-ethyl-methacrylate) (pHEMA), an hydrophilic polymeric hydrogel, onto the complex surface of a 316L steel stent for percutaneous coronary intervention (PCI). By varying process parameters, tuneable thicknesses, from 5 to 20 microm, have been obtained with uniform and homogeneous surface without crack or bridges. Surface characteristics of pHEMA coating onto metal surface have been investigated through FTIR-ATR, contact angle measurement, SEM, EDS and AFM. Moreover, results from Single-Lap-Joint and Pull-Off adhesion tests as well as calorimetric analysis of glass transition temperature suggested that pHEMA deposition is firmly adhered on metallic surface. The pHEMA coating evaluation of roughness, wettability together with its morphological and chemical stability after three cycles of expansion-crimping along with preliminary results after 6 months demonstrates the suitability of the coating for surgical implantation of stent. PMID:19267260

  8. Spatial control over cross-linking dictates the pH-responsive behavior of poly(2-(tert-butylamino)ethyl methacrylate) brushes.

    PubMed

    Alswieleh, Abdullah M; Cheng, Nan; Leggett, Graham J; Armes, Steven P

    2014-02-11

    Surface-initiated atom transfer radical polymerization (ATRP) of 2-(tert-butylamino)ethyl methacrylate (TBAEMA) produced pH-responsive secondary amine-functionalized polymer brushes with dry thicknesses ranging from 4 to 28 nm, as determined by ellipsometry. At low pH, linear PTBAEMA brushes became protonated and highly swollen; brush collapse occurred when the solution pH was increased to ca. 7.7 due to deprotonation. PTBAEMA brushes were subsequently cross-linked using tolylene-2,4-diisocyanate-terminated poly(propylene glycol) (PPG-TGI) in either THF (a good solvent for PTBAEMA) or n-hexane (a poor solvent). The intensity of the C-C-O component (286.5 eV) in the C1s X-ray photoelectron spectrum increased after reaction with PPG-TDI, suggesting that cross-linking was successful in both solvents. Ellipsometry studies indicated that the pH-responsive behavior of these cross-linked brushes is dictated by the spatial location of the PPG-TDI cross-linker. Thus, uniformly cross-linked brushes prepared in THF became appreciably less swollen at a given (low) pH than surface-cross-linked brushes prepared in n-hexane. Micro- and nanopatterned PTBAEMA brushes were prepared via UV irradiation and interference lithography, respectively, and characterized by atomic force microscopy. The change in brush height was determined as a function of pH, and these AFM observations correlated closely with the ellipsometric studies. PMID:24417283

  9. Spatial Control over Cross-Linking Dictates the pH-Responsive Behavior of Poly(2-(tert-butylamino)ethyl methacrylate) Brushes

    PubMed Central

    2014-01-01

    Surface-initiated atom transfer radical polymerization (ATRP) of 2-(tert-butylamino)ethyl methacrylate (TBAEMA) produced pH-responsive secondary amine-functionalized polymer brushes with dry thicknesses ranging from 4 to 28 nm, as determined by ellipsometry. At low pH, linear PTBAEMA brushes became protonated and highly swollen; brush collapse occurred when the solution pH was increased to ca. 7.7 due to deprotonation. PTBAEMA brushes were subsequently cross-linked using tolylene-2,4-diisocyanate-terminated poly(propylene glycol) (PPG-TGI) in either THF (a good solvent for PTBAEMA) or n-hexane (a poor solvent). The intensity of the C–C–O component (286.5 eV) in the C1s X-ray photoelectron spectrum increased after reaction with PPG-TDI, suggesting that cross-linking was successful in both solvents. Ellipsometry studies indicated that the pH-responsive behavior of these cross-linked brushes is dictated by the spatial location of the PPG-TDI cross-linker. Thus, uniformly cross-linked brushes prepared in THF became appreciably less swollen at a given (low) pH than surface-cross-linked brushes prepared in n-hexane. Micro- and nanopatterned PTBAEMA brushes were prepared via UV irradiation and interference lithography, respectively, and characterized by atomic force microscopy. The change in brush height was determined as a function of pH, and these AFM observations correlated closely with the ellipsometric studies. PMID:24417283

  10. Biosensor utilizing a liquid crystal/water interface functionalized with poly(4-cyanobiphenyl-4'-oxyundecylacrylate-b-((2-dimethyl amino) ethyl methacrylate)).

    PubMed

    Omer, Muhammad; Khan, Mashooq; Kim, Young Kyoo; Lee, Joon Hyung; Kang, Inn-Kyu; Park, Soo-Young

    2014-09-01

    The interface between the nematic liquid crystal, 4-cyano-4'-pentylbiphenyl (5CB) and water within a transmission electron microscopy (TEM) grid cell coated with the pH-dependent weak cationic amphiphilic block copolymer poly((4-cyanobiphenyl-4'-oxyundecylacrylate)-b-((2-dimethyl amino) ethyl methacrylate)) (LCP-b-PDMAEMA) (which was successfully synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization) was subsequently evaluated for protein and deoxyribonucleic acid (DNA) detection. The LCP-b-PDMAEMA monolayer was fabricated using a Langmuir Blodgett trough, transferred to the 5CB-filled TEM grid, and placed on the octadecyltrichlorosilane-coated glass (TEMPDMAEMA) in such a way that the LCP chains were immersed in the 5CB while the PDMAEMA chains were pointed away from the 5CB surface and immersed in water. Several model proteins such as bovine serum albumin (BSA), hemoglobin (Hb), and chymotrypsinogen (ChTg) were tested at pH values ranging from 2 to 12 to determine the role of the charge state of the protein on protein detection by a weak polyelectrolyte such as PDMAEMA. PDMAEMA contains cationic and neutral states below and above the pKa value, respectively, and is thus able to absorb proteins below its pKa threshold through electrostatic interactions. BSA exhibited a homeotropic to planar (H-P) change in orientation within the TEMPDMAEMA grid cell at concentrations greater than 0.02wt% within the pH range between the isoelectric point (pI) of BSA and the pKa of PDMAEMA, where the charge states of BSA and PDMAEMA were negative and positive, respectively. However, this change in orientation did not occur with other proteins that exhibited a pI higher than the pKa of PDMAEMA due to the electrostatic repulsions resulting from their same cationic charges. This result indicates that the electrostatic interactions between proteins and PDMAEMA are a major contributing factor for protein detection by the H-P transformation within the

  11. Polyplex formation between four-arm poly(ethylene oxide)-b-poly(2-(diethylamino)ethyl methacrylate) and plasmid DNA in gene delivery.

    PubMed

    He, E; Yue, C Y; Simeon, F; Zhou, L H; Too, H P; Tam, K C

    2009-12-01

    Amphiphilic polyelectrolytes comprising cationic and uncharged hydrophilic segments condensed negatively charged DNA to form a core-shell structure stabilized by a layer of hydrophilic corona chains. At physiological pH, four-arm star-shaped poly(ethylene oxide)-b-poly(2-(diethylamino)ethyl methacrylate) (four-arm PEO-b-PDEAEMA) block copolymer possessed positively charged amine groups that interacted with negatively charged plasmid DNA to form polymer/DNA complexes. The mechanism and physicochemical properties of the complex formation were investigated at varying molar ratio of amine groups on polymer chains and phosphate group on plasmid DNA segments (N/P ratio). The capability of the star block copolymer to condense DNA was demonstrated through gel electrophoresis and ethidium bromide exclusion assay. In the absence of salt, the hydrodynamic radius of polyplexes was about 94 nm at low polymer/DNA ratio, and it decreased to about 34 nm at large N/P ratios, forming a compact spherical structure with a weighted average molecular weight of 4.39 +/- 0.22 x 10(6) g/mol. Approximately 15 polymeric chains were required to condense a plasmid DNA. The addition of monovalent salt to the polyplexes significantly altered the size of the complexes, which would have an impact on cell transfection. Because of the electrostatic interaction induced by the diffusion of small ions, the polyplex increased in size to about 53 nm with a less compact structure. In vitro cytotoxicty of polymer and polymer/pDNA complexes were evaluated, and the polyplexes exhibited low toxicity at low N/P ratios. At N/P ratio of 4.5, the four-arm PEO-b-PDEAEMA showed the highest level of transfection in Neuro-2A cells. These observations showed that the star-shaped multi-arm polymers offers interesting properties in self-association and condensation ability for plasmid DNA and can serve as a nonviral DNA delivery system. PMID:19048636

  12. Poly(2-dimethylamino ethylmethacrylate)-based polymers to camouflage red blood cell antigens.

    PubMed

    Cerda-Cristerna, Bernardino Isaac; Cottin, Sophie; Flebus, Luca; Pozos-Guillén, Amaury; Flores, Héctor; Heinen, Ernst; Jolois, Olivier; Gérard, Christiane; Maggipinto, Gianni; Sevrin, Chantal; Grandfils, Christian

    2012-04-01

    Poly(2-dimethylamino-ethylmethacrylate) (PDMAEMA) is a cationic polymer when dissolved in a 7.4 pH fluid. Owing to its ionic nature, this polycation interacts with the negatively charged cell membrane surface of red blood cells (RBCs). The electrostatic self-assembly of PDMAEMA on RBCs membrane can be employed for inducing the formation of a polymeric shield camouflaging blood group antigens on RBCs as a valuable strategy for developing "universal RBCs" for blood transfusion. The purpose of this research was to evaluate the camouflaging ability of PDMAEMA homopolymers and PDMAEMA-co-poly(ethylene glycol) copolymers differing in molecular weight and architecture. Surprisingly, the PDMAEMAs caused a partially masking, no masking, and sensitization of the same RBCs population. The MW and architecture of the polymers as well as temperature of PDMAEMA-RBCs treatment influenced the results observed. Herein, the very particular reactivity of PDMAEMAs and RBCs is analyzed and discussed. PMID:22416913

  13. Gd@C82 metallofullerenes for neutron capture therapy—fullerene solubilization by poly(ethylene glycol)-block-poly(2-(N, N-diethylamino)ethyl methacrylate) and resultant efficacy in vitro

    NASA Astrophysics Data System (ADS)

    Horiguchi, Yukichi; Kudo, Shinpei; Nagasaki, Yukio

    2011-08-01

    Poly(ethylene glycol)-block-poly(2-(N,N-diethylamino)ethyl methacrylate) (PEG-b-PAMA) was found to solubilize fullerenes such as C60, and this technique was applied to metallofullerenes. Gd@C82 was easily dissolved in water in the presence of PEG-b-PAMA without any covalent derivatization, forming a transparent complex about 20-30 nm in diameter. Low cytotoxicity was confirmed in vitro. Neutron irradiation of cultured cells (colon-26 adenocarcinoma) with Gd@C82-PEG-b-PAMA-complexed nanoparticles showed effective cytotoxicity, indicating the effective emission of gamma rays and internal conversion electrons produced from the neutron capture reaction of Gd. This result suggests a potentially valuable approach to gadolinium-based neutron capture therapy.

  14. Pentablock copolymers of pluronic F127 and modified poly(2-dimethyl amino)ethyl methacrylate for internalization mechanism and gene transfection studies

    PubMed Central

    Huang, Shih-Jer; Wang, Tzu-Pin; Lue, Sheng-I; Wang, Li-Fang

    2013-01-01

    Cationic polymers are one of the major nonviral gene delivery vectors investigated in the past decade. In this study, we synthesized several cationic copolymers using atom transfer radical polymerization (ATRP) for gene delivery vectors: pluronic F127-poly(dimethylaminoethyl methacrylate) (PF127-pDMAEMA), pluronic F127-poly (dimethylaminoethyl methacrylate-tert-butyl acrylate) (PF127-p(DMAEMA-tBA)), and pluronic F127-poly(dimethylaminoethyl methacrylate-acrylic acid) (PF127-p(DMAEMA-AA)). The copolymers showed high buffering capacity and efficiently complexed with plasmid deoxyribonucleic acid (pDNA) to form nanoparticles 80–180 nm in diameter and with positive zeta potentials. In the absence of 10% fetal bovine serum, PF127-p(DMAEMA-AA) showed the highest gene expression and the lowest cytotoxicity in 293T cells. After acrylic acid groups had been linked with a fluorescent dye, the confocal laser scanning microscopic image showed that PF127-p(DMAEMA-AA)/pDNA could efficiently enter the cells. Both clathrin-mediated and caveolae-mediated endocytosis mechanisms were involved. Our results showed that PF127-p(DMAEMA-AA) has great potential to be a gene delivery vector. PMID:23745045

  15. Terpolymers of ethyl acrylate/methacrylic acid/unsaturated acid ester of alcohols and acids as anti-settling agents in coal water slurries

    SciTech Connect

    Savoly, A.; Villa, J.L.; Grinstein, R.H.; Nachfolger, S.J.

    1988-05-17

    This patent describes a pumpable stabilized coal water slurry, having a coal content of at least about 50% by weight wherein at least 80% of the coal particles are about 200 mesh or finer, containing from about 0.01% to about 1% by weight of the slurry of a water soluble terpolymer of ethylacrylate (A), metacrylic acid (B) and a third monomer (C) selected from the group consisting of an unsaturated carboxylic acid ester of an alcohol and an ethoxylated carboxylic acid. The unsaturated carboxylic acid is a mono- or di- basic unsaturated carboxylic acid of 3 to 10 carbon atoms selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid.

  16. Synthesis, characterisation, and in vitro cellular uptake kinetics of nanoprecipitated poly(2-methacryloyloxyethyl phosphorylcholine)-b-poly(2-(diisopropylamino)ethyl methacrylate) (MPC-DPA) polymeric nanoparticle micelles for nanomedicine applications

    NASA Astrophysics Data System (ADS)

    Salvage, Jonathan P.; Smith, Tia; Lu, Tao; Sanghera, Amendeep; Standen, Guy; Tang, Yiqing; Lewis, Andrew L.

    2016-01-01

    Nanoscience offers the potential for great advances in medical technology and therapies in the form of nanomedicine. As such, developing controllable, predictable, and effective, nanoparticle-based therapeutic systems remains a significant challenge. Many polymer-based nanoparticle systems have been reported to date, but few harness materials with accepted biocompatibility. Phosphorylcholine (PC) based biomimetic materials have a long history of successful translation into effective commercial medical technologies. This study investigated the synthesis, characterisation, nanoprecipitation, and in vitro cellular uptake kinetics of PC-based polymeric nanoparticle micelles (PNM) formed by the biocompatible and pH responsive block copolymer poly(2-methacryloyloxyethyl phosphorylcholine)-b-poly(2-(diisopropylamino)ethyl methacrylate) (MPC-DPA). Atom transfer radical polymerisation (ATRP), and gel permeation chromatography (GPC) were used to synthesise and characterise the well-defined MPC100-DPA100 polymer, revealing organic GPC, using evaporative light scatter detection, to be more accurate than aqueous GPC for this application. Subsequent nanoprecipitation investigations utilising photon correlation spectroscopy (PCS) revealed PNM size increased with polymer concentration, and conferred Cryo-stability. PNM diameters ranged from circa 64-69 nm, and increased upon hydrophobic compound loading, circa 65-71 nm, with loading efficiencies of circa 60 % achieved, whilst remaining monodisperse. In vitro studies demonstrated that the PNM were of low cellular toxicity, with colony formation and MTT assays, utilising V79 and 3T3 cells, yielding comparable results. Investigation of the in vitro cellular uptake kinetics revealed rapid, 1 h, cellular uptake of MPC100-DPA100 PNM delivered fluorescent probes, with fluorescence persistence for 48 h. This paper presents the first report of these novel findings, which highlight the potential of the system for nanomedicine application

  17. Functionalization of lignin through ATRP grafting of poly(2-dimethylaminoethyl methacrylate) for gene delivery.

    PubMed

    Liu, Xiaohong; Yin, Hui; Zhang, Zhongxing; Diao, Bishuo; Li, Jun

    2015-01-01

    The biomass kraft lignin was modified into lignin-based macroinitiators (LnMI) through esterification of the alcohol and phenol functional groups on lignin backbone with 2-bromo-isobutyric bromide under mild condition. Then a series of cationic amphiphilic lignin-based graft copolymers were synthesized by atom transfer radical polymerization (ATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA) starting from the lignin-based macroinitiators. These copolymers, denoted as LnPDMAEMA, had a hyperbranched structure with a hydrophobic backbone of lignin and multiple cationic hydrophilic arms of PDMAEMA. The LnPDMAEMA copolymers were characterized by (1)H NMR and elemental analysis (EA), and studied in terms of their DNA binding capability, formation of nanoparticles with plasmid DNA (pDNA), cytotoxicity, and gene transfection in cultured cells. It was found that all the copolymers could efficiently compact pDNA into nanoparticles with sizes ranging from 100 to 200 nm at N/P ratios of 5 or higher. The cytotoxicity of these copolymers depends greatly on the chain length of PDMAEMA arms, the longer the PAMAEMA chain the higher the cytotoxicity. Luciferase assay was used to study the in vitro gene transfection for the LnPDMAEMA copolymers in different cell lines. The gene transfection efficiency of these copolymers was dependent on the grafted PDMAEMA chain length and N/P ratio. Generally, the transfection efficiency decreased with the increase of PAMAEMA length at N/P ratio of 20 or higher. It is very interesting that one of the LnPDMAEMA copolymers with very short arm length (degree of average DMAEMA units=5.5) showed excellent in vitro transfection efficiency that was comparable or even higher than that of branched PEI (25K). These novel biomass-based LnPDMAEMA hyperbranched copolymers can be a promising nonviral gene vectors for future gene delivery application. PMID:25506805

  18. Ammonium methacrylate

    Integrated Risk Information System (IRIS)

    Ammonium methacrylate ; CASRN 16325 - 47 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcin

  19. Methyl methacrylate

    Integrated Risk Information System (IRIS)

    Methyl methacrylate ; CASRN 80 - 62 - 6 ( 03 / 02 / 98 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  20. 2′-(2-((dimethylamino)methyl)-4′-(2-fluoroalkoxy)-phenylthio)benzenamine Derivatives as Serotonin Transporter Imaging Agents

    PubMed Central

    Parhi, Ajit K.; Wang, Julie L.; Oya, Shunichi; Choi, Seok-Rye; Kung, Mei-Ping; Kung, Hank F.

    2008-01-01

    A novel series of ligands with substitutions at the 5-position on phenyl ring A and at the 4′-position on phenyl ring B of 2′-(2-((dimethylamino)methyl)-4′-(2-fluoro- alkoxy)phenylthio)benzenamine (4′-2-fluoroethoxy derivatives, 28–31 and 4′-3-fluoro propoxy derivatives, 40–42) were prepared and tested as serotonin transporter (SERT) imaging agents. The new ligands displayed high binding affinities to SERT (Ki ranging from 0.07 to 1.5 nM). The corresponding 18F labeled compounds, which can be prepared readily, showed excellent brain uptake and retention after iv injection in rats. The hypothalamus region showed high uptake values between 0.74 to 2.2 % dose/g at 120 min post iv injection. Significantly, the hypothalamus to cerebellum ratios (target to non-target ratios) at 120 min were 7.8 and 7.7 for [18F]28 and [18F]40, respectively. The selective uptake and retention in the hypothalamus, which has a high concentration of SERT binding sites, demonstrated that [18F]28 and [18F]40 are promising PET (positron emission computed tomography) imaging agents for mapping SERT binding sites in the brain. PMID:18052090

  1. Nizatidine, N-[2-[[[2-[(dimethylamino)methyl]-4-thiazolyl]methyl]thio]ethyl]-N‧-methyl-2-nitro-1,1-ethenediamine

    NASA Astrophysics Data System (ADS)

    Stephenson, Gregory A.; Wozniak, Timothy J.; Stowell, Joseph G.; Byrn, Stephen R.

    1996-06-01

    C 12H 21N 5S 2O 2, Mr = 331.46, triclinic, P1¯, a = 7.3645(5), b = 8.8785(9), c = 25.678(4) Å, α = 89.35(1)°, β = 82.49(1)°, γ = 87.46(1)°, V = 1662.9(5) Å 3, Z = 4, D x = 1.324 g cm -3, λ(Cu Kα) = 1.54184 Å, μ = 29.57 cm -1, F(000) = 704.0, T = 293 K, final R = 0.057 for 4830 observed reflections. Nizatidine, Axid®, is a selective H 2-receptor antagonist used in the treatment of duodenal ulcers. The pharmaceutical nizatidine crystallizes with two independent molecules in the asymmetric unit. The two molecules have similar conformations, with the exception of the dimethylamino group. The bisalkylamino-2-nitroethene moiety differs from the structurally related hydrogen oxalate salt form of ranitidine in that the nitro group of nizatidine is the cis geometrical isomer with respect to the ethylamino group.

  2. Icosapent Ethyl

    MedlinePlus

    ... weight loss, exercise) to reduce the amount of triglycerides (a fat-like substance) in your blood. Icosapent ... ethyl may work by decreasing the amount of triglycerides and other fats made in the liver.

  3. Heterocyclic methacrylates for clinical applications. II. Room temperature polymerizing systems for potential clinical use.

    PubMed

    Patel, M P; Braden, M

    1991-09-01

    A number of useful room temperature polymerizing resins were formulated, based on poly(ethyl methacrylate) powder and a range of low shrinkage heterocyclic methacrylate monomers. N,N-dimethyl-p-toluidine or p-tolyl diethanolamine were used as activating amines, but the latter material is less active and some care is necessary with respect to the source of the monomer. Isobornyl methacrylate is a useful diluent monomer to reduce the exotherm. PMID:1742408

  4. X-ray structure and conformational study of tris(2-(dimethylamino)phenyl)methanol: Roles of hydrogen bond in conformational conversions of molecules

    NASA Astrophysics Data System (ADS)

    Niu, Yong-Ping; Zhang, Jun-Kai; Wang, Xiao-Wei; Ma, Xiao-Fei; Cai, Jun-Qing; Zhou, Na; Zheng, Zhi-Wu; Hua, Rui-Mao

    2015-07-01

    Tris(2-(dimethylamino)phenyl)methanol, (2-(Me)2N-C6H4)3COH, was synthesized and characterized by using NMR, EA and ESI-MS. Single crystal of the 2-syn/1-anti conformer of the tertiary alcohol was obtained and analyzed by X-ray diffraction. The variable-temperature 1H NMR experiments reveal that, in solution, the tertiary alcohol is an equilibrium mixture of four conformers, all-syn, 2-syn/1-anti, 1-syn/2-anti and all-anti. The results show that hydrogen bond plays an important role in both intra- and inter-conformational conversions of molecules. The intra-conformational conversions within specific conformers are just helical changes. The inter-conformational conversions between conformers occurred via one-ring flip process.

  5. Ethyl carbamate

    Integrated Risk Information System (IRIS)

    Ethyl carbamate ; CASRN 51 - 79 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  6. Ethyl chloride

    Integrated Risk Information System (IRIS)

    Ethyl chloride ; CASRN 75 - 00 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  7. Ethyl ether

    Integrated Risk Information System (IRIS)

    Ethyl ether ; CASRN 60 - 29 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  8. Ethyl acetate

    Integrated Risk Information System (IRIS)

    Ethyl acetate ; CASRN 141 - 78 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  9. Dielectric relaxation study of mixtures of alkyl methacrylates and 1-alcohols using time-domain reflectometry

    NASA Astrophysics Data System (ADS)

    Sivagurunathan, P.; Dharmalingam, K.; Ramachandran, K.; Prabhakar Undre, B.; Khirade, P. W.; Mehrotra, S. C.

    2006-05-01

    Dielectric relaxation measurements on alkyl methacrylates (methyl methacrylate, ethyl methacrylate and butyl methacrylate) with 1-alcohols (1-propanol, 1-pentanol, 1-heptanol, 1-octanol and 1-decanol) have been carried out using time-domain reflectometry (TDR) over the frequency range 10 MHz to 20 GHz at 303 K for different concentrations of alcohols. The dielectric parameters, namely the static dielectric constant (ɛ0), the dielectric constant at microwave frequencies (ɛ∞) and the relaxation time (τ) were determined. The Kirkwood correlation factor, which contains information regarding solute-solvent interaction and corresponding structural information, the excess permittivity and the excess inverse relaxation time were also determined. The values of the static dielectric constant and the relaxation time increase with the percentage of alkyl methacrylates in the alcohol, whereas the static dielectric constant decreases and the relaxation time increases with an increase in the alkyl chain length of both the methacrylates and the alcohols.

  10. The acute aquatic toxicity of a series of acrylate and methacrylate esters

    SciTech Connect

    Staples, C.A.; McLaughlin, J.E.; Hamilton, J.D.

    1994-12-31

    Acute aquatic toxicity data for several acrylate and methacrylate esters were reviewed. Acrylates included acrylic acid, ethyl-, and butyl-acrylate. Methacrylates included methacrylic acid, methyl-, and butyl-methacrylate. Tests were 48 hr or 96 hr standard flow through (invertebrates and fish) assays (measured exposure concentrations). These data are currently used in a risk assessment of acrylate/methacrylate environmental safety. Algal growth (Selanastrum capricomutum) 96 hr EC{sub 50}s were 0.17 mg/L (NOEC < 0.13 mg/L) for acrylic acid, 11.0 mg/L (NOEC < 6.5 mg/L) for ethyl acrylate, and 5.2 mg/L (NOEC < 3.8 mg/L) for butyl acrylate. Invertebrate (Daphnia magna) 48 hr LC{sub 50}s were 95.0 mg/L (NOEC 23.0 mg/L) for acrylic acid, 7.9 mg/L (NOEC 3.4 mg/L) for ethyl acrylate, and 8.2 mg/L (NOEC 2.4 mg/L) for butyl acrylate. Rainbow trout (Oncorhynchus mykiss) 96 hr LC{sub 50}s were 27.0 mg/L (NOEC 6.3 mg/L) for acrylic acid, 4.6 mg/L (NOEC 0.78 mg/L) for ethyl acrylate, and 5.2 mg/L (NOEC 3.8 mg/L) for butyl acrylate. Algae 96 hr EC{sub 50}s were 0.59 mg/L (NOEC 0.38 mg/L) for methacrylic acid, 170.0 mg/L (NOEC 100.0 mg/L) for methyl methacrylate, and 130.0 mg/L for butyl methacrylate. Daphnia magna 48 hr LC{sub 50}s were > 130.0 mg/L (NOEC 130.0 mg/L) for methacrylic acid, 69.0 mg/L (NOEC 48.0 mg/L) for methyl methacrylate, and 32.0 mg/L (NOEC 23.0 mg/L) for butyl methacrylate. Trout 96 hr LC{sub 50}s were 85.0 mg/L (NOEC 12.0 mg/L) for methacrylic acid and > 79.0 mg/L (NOEC 40.0 mg/L) for methyl methacrylate. The fathead minnow (Pimephales promelas) 96 hr LC{sub 50} was 11.0 mg/L for butyl methacrylate.

  11. Low molecular weight poly (2-dimethylamino ethylmethacrylate) polymers with controlled positioned fluorescent labeling: Synthesis, characterization and in vitro interaction with human endothelial cells.

    PubMed

    Flebus, Luca; Lombart, François; Sevrin, Chantal; Defraigne, Jean-Olivier; Peters, Pierre; Parhamifar, Ladan; Molin, Daniel G M; Grandfils, Christian

    2015-01-15

    Poly (2-dimethylamino ethylmethacrylate) (PDMAEMA) is an attractive non-degradable polymer studied as nonviral vector for gene delivery but it can be also adopted for delivery of other biopharmaceutical drugs. As a parenteral carrier, the PDMAEMA free form (FF) might interact with tissues and cells. Few data are available on its selective internalization and efflux from cells, while the majority of studies published have followed the distribution of DNA complexed with PDMAEMA. In order to address polycation safety, the first aim was to synthesize by atom transfer radical polymerisation (ATRP) fluorescent labeled PDMAEMA of low molecular weight (Mw) (below 15 kDa), controlling the position and density of fluorescein. The second goal was to analyze the possible difference in uptake and subcellular distribution of this labeled FF polycation between human umbilical vein endothelial cells (HUVEC) and hCMEC/D3 cells. These two cell lines have been chosen in order to detect selectivity towards the blood-brain barrier (BBB). In both cases, polycation was detected along the plasma membrane followed by progressive migration to the peri-nuclear region, where it overlapped with lysosomal structures. The analysis by fluorescence-activated cell sorting (FACS) of the PDMAEMA uptake by hCMEC/D3 cells showed a significant (p<0.05) inhibition (40%) in presence of 2-dexoxy-D-glucose inhibitor, a result supporting an energy-dependence mechanism(s). Cytotoxicity study showed that low Mw PDMAEMA (10 kDa) lead to a minor cytotoxicity compared to the higher ones. As main conclusion this study highlights the similitude in cell trafficking of FF PDMAEMA and data previously reported for PDMAEMA/DNA complexes. PMID:25448588

  12. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ethyl alcohol containing ethyl acetate....

  13. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ethyl alcohol containing ethyl acetate....

  14. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate....

  15. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ethyl alcohol containing ethyl acetate....

  16. 21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the requirement of 27 CFR 21.62, being not less than 92.5 percent ethyl alcohol, each 100 gallons... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ethyl alcohol containing ethyl acetate....

  17. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ...This regulation establishes an exemption from the requirement of a tolerance for residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft copolymer when used as an inert ingredient in a pesticide chemical formulation. Akzo Noel Surface Chemistry LLC submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an......

  18. 21 CFR 73.3121 - Poly(hydroxyethyl methacrylate)-dye copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...(hydroxyethyl methacrylate). The dyes that may be used alone or in combination are (1) Reactive Black 5 (CAS Reg...)-, sulfo((4-((2-sulfooxy)ethyl)sulfonyl)phenyl)amino) sulfonyl derivs] (CAS Reg. No. 73049-92-0); (3) Reactive Orange 78 CAS Reg. No. 68189-39-9); (4) Reactive Yellow 15 (CAS Reg. No. 60958-41-0); (5)...

  19. 21 CFR 73.3121 - Poly(hydroxyethyl methacrylate)-dye copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...(hydroxyethyl methacrylate). The dyes that may be used alone or in combination are (1) Reactive Black 5 (CAS Reg...)-, sulfo((4-((2-sulfooxy)ethyl)sulfonyl)phenyl)amino) sulfonyl derivs] (CAS Reg. No. 73049-92-0); (3) Reactive Orange 78 CAS Reg. No. 68189-39-9); (4) Reactive Yellow 15 (CAS Reg. No. 60958-41-0); (5)...

  20. Contact dermatitis to methyl methacrylate.

    PubMed

    Kassis, V; Vedel, P; Darre, E

    1984-07-01

    2 cases of contact dermatitis to methyl methacrylate monomer are presented. The patients are nurses who mixed bone cement at orthopedic operations. During the procedure, they used 2 pairs of gloves (latex). Butyl rubber gloves are recommended for methyl methacrylate monomer to avoid sensitization and/or cumulative irritant contact dermatitis on the hands. PMID:6204812

  1. Toward pH-responsive coating materials--high-throughput study of (meth)acrylic copolymers.

    PubMed

    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. PMID:24964068

  2. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... methacrylate and substituted methacrylate. 721.9492 Section 721.9492 Protection of Environment ENVIRONMENTAL... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate. Link to an amendment published at 79 FR 34638, June 18, 2014....

  3. Chlorimuron-ethyl

    Integrated Risk Information System (IRIS)

    Chlorimuron - ethyl ; CASRN 90982 - 32 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinog

  4. Methyl ethyl ketone (MEK)

    Integrated Risk Information System (IRIS)

    Methyl ethyl ketone ( MEK ) ( CASRN 78 - 93 - 3 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  5. Ethyl alcohol production

    SciTech Connect

    Hofman, V.; Hauck, D.

    1980-11-01

    Recent price increases and temporary shortages of petroleum products have caused farmers to search for alternate sources of fuel. The production of ethyl alcohol from grain is described and the processes involved include saccharification, fermentation and distillation. The resulting stillage has potential as a livestock feed.

  6. Terminal-Selective Transesterification of Chlorine-Capped Poly(Methyl Methacrylate)s: A Modular Approach to Telechelic and Pinpoint-Functionalized Polymers.

    PubMed

    Ogura, Yusuke; Terashima, Takaya; Sawamoto, Mitsuo

    2016-04-20

    Terminal-selective transesterification of chlorine-capped poly(methyl methacrylate)s (PMMA-Cl) with alcohols was developed as a modular approach to create telechelic and pinpoint-functionalized polymers. Being sterically less hindered and electronically activated, both the α-end ethyl ester and ω-end methyl ester of PMMA-Cl were efficiently and selectively transesterified with diverse alcohols in the presence of a titanium alkoxide catalyst, while retaining the pendent esters intact, to almost quantitatively give various chlorine-capped telechelic PMMAs. In sharp contrast to conventional telechelic counterparts, the telechelic polymers obtained herein yet carry a chlorine atom at the ω-terminal to further work as a macroinitiator in living radical polymerization. The iterative process of living radical polymerization and terminal-selective transesterification successfully afforded unique pinpoint-functionalized polymers where a single functional monomer unit was introduced into the desired site of the polymer chains. PMID:27040865

  7. Thermomechanical behavior of amorphous tactic methacrylate polymers

    NASA Technical Reports Server (NTRS)

    Kiran, E.; Gillham, J. K.; Gipstein, E.

    1974-01-01

    Dynamic mechanical spectra of amorphous stereoregular poly(methyl methacrylate)s and poly(t-butyl methacrylate)s with assigned microtacticities are presented and discussed. An intermolecular argument is invoked to account for the higher glass transition temperature of syndiotactic vis a vis isotactic PMMA, in spite of the higher density of the latter at 30 C. An argument is presented to show that the ratio of glassy-region relaxation temperature to glass transition temperature is not only a measure of the degree of coupling of the beta and glass transition processes, but also of the degree to which intermolecular factors influence these processes. The greater extent of the low-temperature irreversibilities observed in the thermomechanical spectra of poly(t-butyl methacrylate)s is attributed to the brittle character induced by the bulky side groups which presumably weaken cohesive forces.

  8. Sulfone-Containing Methacrylate Homopolymers: Wetting and Thermal Properties.

    PubMed

    Fujii, Shota; McCarthy, Thomas J

    2016-01-26

    Although the sulfonyl functional group has a large dipole moment and compounds containing them (sulfones) have correspondingly high dielectric constants, this chemical structure has been neglected for use as a functional group to render surfaces hydrophilic. We have prepared three methacrylate polymers containing side chains capped with sulfolane, methylsulfone, and ethylsulfone functionality. The sulfolane-containing polymer exhibits an unusually high glass transition temperature (Tg = 188°C) for a methacrylate polymer and slightly different thermal degradation behavior than the other two sulfone-containing polymers, likely due to the bulky structure of the sulfolane group in the polymer side chain. At macroscopic polymer film/water interfaces, the sulfone-containing side chains exposed to the interface impart hydrophilic properties as assessed by contact angle analysis. The hydrophilicities of sulfolane and methylsulfone surfaces are similar, and greater than the ethylsulfone surface. Although the chemical compositions of the sulfolane and ethylsulfone polymers are almost identical, the five-membered ring structure of sulfolane allows the sulfonyl moiety to be exposed at the interface in a manner similar to that of the methylsulfone polymer. The sulfonyl group at the ethylsulfone polymer/water interface is slightly masked by the ethyl group. Interestingly, the sulfolane surface displays a higher affinity to methylene iodide and n-hexadecane probe fluids compared to the other sulfone surfaces, suggesting that the five-membered ring structure of the sulfolane moiety can orient in a manner that shelters the sulfonyl group at hydrophobic interfaces. PMID:26716766

  9. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified methyl methacrylate, 2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10153 Modified methyl methacrylate, 2... reporting. (1) The chemical substance identified generically as modified methyl methacrylate,...

  10. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified methyl methacrylate, 2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10153 Modified methyl methacrylate, 2... reporting. (1) The chemical substance identified generically as modified methyl methacrylate,...

  11. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified methyl methacrylate, 2... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10153 Modified methyl methacrylate, 2... reporting. (1) The chemical substance identified generically as modified methyl methacrylate,...

  12. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  13. 40 CFR 721.10153 - Modified methyl methacrylate, 2-hydroxyethyl methacrylate polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hydroxyethyl methacrylate polymer (generic). 721.10153 Section 721.10153 Protection of Environment...-hydroxyethyl methacrylate polymer (generic). (a) Chemical substance and significant new uses subject to... methacrylate polymer (PMN P-08-6) is subject to reporting under this section for the significant new...

  14. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may... produced by the polymerization of methacrylic acid and divinylbenzene. The divinylbenzene functions as...

  15. Development of methacrylate/silorane hybrid monomer system: Relationship between photopolymerization behavior and dynamic mechanical properties.

    PubMed

    Song, Linyong; Ye, Qiang; Ge, Xueping; Singh, Viraj; Misra, Anil; Laurence, Jennifer S; Berrie, Cindy L; Spencer, Paulette

    2016-07-01

    Resin chemistries for dental composite are evolving as noted by the introduction of silorane-based composites in 2007. This shift in the landscape from methacrylate-based composites has fueled the quest for versatile methacrylate-silorane adhesives. The objective of this study was to evaluate the polymerization behavior and structure/property relationships of methacrylate-silorane hybrid systems. Amine compound ethyl-4-(dimethylamino) benzoate (EDMAB) or silane compound tris(trimethylsilyl) silane (TTMSS) was selected as coinitiators. The mechanical properties of the copolymer were improved significantly at low concentrations (15, 25, or 35 wt %) of silorane when EDMAB was used as coinitiator. The rubbery moduli of these experimental copolymers were increased by up to 260%, compared with that of the control (30.8 ± 1.9 MPa). Visible phase separation appeared in these formulations if the silorane concentrations in the formulations were 50-75 wt %. The use of TTMSS as coinitiator decreased the phase separation, but there was a concomitant decrease in mechanical properties. In the neat methacrylate formulations, the maximum rates of free-radical polymerization with EDMAB or TTMSS were 0.28 or 0.06 s(-1) , respectively. In the neat silorane resin, the maximum rates of cationic ring-opening polymerization with EDMAB or TTMSS were 0.056 or 0.087 s(-1) , respectively. The phase separation phenomenon may be attributed to differences in the rates of free-radical polymerization of methacrylates and cationic ring-opening polymerization of silorane. In the hybrid systems, free-radical polymerization initiated with EDMAB led to higher crosslink density and better mechanical properties under dry/wet conditions. These beneficial effects were, however, associated with an increase in heterogeneity in the network structure. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 841-852, 2016. PMID:25953619

  16. Hyperbranched Polymers by Type II Photoinitiated Self-Condensing Vinyl Polymerization.

    PubMed

    Aydogan, Cansu; Ciftci, Mustafa; Yagci, Yusuf

    2016-04-01

    Type II photoinitiated self-condensing vinyl polymerization for the preparation of hyperbranched polymers is explored using 2-hydroxyethyl methacrylate (HEMA) or 2-(dimethylamino)ethyl methacrylate (DMAEMA), and methyl methacrylate as hydrogen donating inimers and comonomer, respectively, in the presence of benzophenone and camphorquinone under UV and visible light. Upon irradiation at the corresponding wavelength, the excited photoinitiator abstracts hydrogen from HEMA or DMAEMA leading to the formation of initiating radicals. Depending on the concentration of inimers, type of the photoinitiator, and irradiation time, hyperbranched polymers with different branching densities and cross-linked polymers are formed. PMID:26785924

  17. Photolithography with polymethyl methacrylate (PMMA)

    NASA Astrophysics Data System (ADS)

    Carbaugh, Daniel J.; Wright, Jason T.; Parthiban, Rajan; Rahman, Faiz

    2016-02-01

    Polymethyl methacrylate (PMMA) is widely used as an electron beam resist but is not used as a photoresist because of its insensitivity to electromagnetic radiation with wavelengths longer than about 300 nm. In this paper we describe a technique for performing conventional photolithography with high molecular weight PMMA at the widely used 365 nm i-line wavelength. The technique involves photosensitizing PMMA with Irgacure 651—a commercially available photo-initiator that can cause PMMA strands to cross-link. Optimum amount of Irgacure can produce a negative tone photoresist with adequate photosensitivity and plasma etch resistance. We describe this technique in detail with complete processing conditions and discuss the effects of varying Irgacure 651 concentration in PMMA as well as changes in UV exposure dose. We also show example structures patterned with commonly available materials and equipment. Finally, we show that it is possible to carry out gradient lithography with this approach, in order to produce structures in relief in photosensitive PMMA.

  18. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  19. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  20. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2010 CFR

    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...

  1. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  2. Amphiphilic graft copolymers with ethyl cellulose backbone: Synthesis, self-assembly and tunable temperature-CO2 response.

    PubMed

    Yuan, Weizhong; Zou, Hui; Shen, Jin

    2016-01-20

    Amphiphilic ethyl cellulose-graft-poly(N,N-dimethylaminoethyl methacrylate) (EC-g-PDMAEMA) and ethyl cellulose-graft-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate) (EC-g-P(MEO2MA-co-DMAEMA)) graft copolymers were easily synthesized by atom transfer radical polymerization (ATRP). The micelles self-assembled from the copolymer presented switchable temperature-CO2 dually responsive properties. The value of lower critical solution temperature (LCST) for the copolymer micelle solutions could be adjusted by CO2/Ar. Moreover, due to the alteration of the ratio of DMAEMA to MEO2MA, the LCST values of the micelle solutions decreased with the increase of MEO2MA in copolymer. The temperature-CO2 dually responsive properties of the copolymer were reversible and could be accomplished through altering the temperature and bubbling CO2/Ar. The hydrodynamic radius (Rh) of the copolymer micelles was also influenced by the ratio of DMAEMA to MEO2MA and the stimuli of temperature and CO2/Ar. As a drug release system, the copolymer micelles could achieve the control release of doxorubicin (DOX) by changing the temperature and alternatively bubbling CO2/Ar. PMID:26572349

  3. Polymerization of novel methacrylated anthraquinone dyes

    PubMed Central

    Dollendorf, Christian; Kreth, Susanne Katharina; Choi, Soo Whan

    2013-01-01

    Summary A new series of polymerizable methacrylated anthraquinone dyes has been synthesized by nucleophilic aromatic substitution reactions and subsequent methacrylation. Thereby, green 5,8-bis(4-(2-methacryloxyethyl)phenylamino)-1,4-dihydroxyanthraquinone (2), blue 1,4-bis(4-((2-methacryloxyethyl)oxy)phenylamino)anthraquinone (6) and red 1-((2-methacryloxy-1,1-dimethylethyl)amino)anthraquinone (12), as well as 1-((1,3-dimethacryloxy-2-methylpropan-2-yl)amino)anthraquinone (15) were obtained. By mixing of these brilliant dyes in different ratios and concentrations, a broad color spectrum can be generated. After methacrylation, the monomeric dyes can be covalently emplaced into several copolymers. Due to two polymerizable functionalities, they can act as cross-linking agents. Thus, diffusion out of the polymer can be avoided, which increases the physiological compatibility and makes the dyes promising compounds for medical applications, such as iris implants. PMID:23503994

  4. Photocontrol over the Disorder-to-Order Transition (DOT) in Thin Film of Polystyrene-block-Poly(methyl methacrylate) Block Copolymers Containing Photodimerizable anthracene functionality

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Li, Le; Wei, Xinyu; Balazs, Anna; Matyjaszewski, Krzysztof; Russell, Thomas

    2010-03-01

    Reversible photocontrol over the disorder-to-order transition (DOT) of block copolymers can be used to fabricate defect-free, long-range ordered nanomaterials over macroscopic distances by ``photo-combing'' the microdomains. Here, we randomly copolymerized anthracene functionalities in a ``dilute'' way with 2-hydroxyethyl methacrylate as the middle block, forming deuterated polystyrene-block-poly(2-(methacryloyloxy)ethyl anthracene-9-carboxylate-random-2-hydroxyethyl methacrylate)-block-poly(methyl methacrylate) (d8-PS-b-P(9AnEMA-r-HEMA)-b-PMMA) triblock copolymers. Upon UV irradiation of a thin film of the phase-mixed triblock copolymer, photodimerization of anthracene links the junction of d8-PS and PMMA blocks and produces an artificial interface to force a phase-separation, i.e. a UV-induced DOT, as evidenced by small angle neutron scattering (SANS). Reversible photocontrol over the DOT can be achieved by taking advantage of photodimerization and photodissociation of anthracene.

  5. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  6. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  7. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  8. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  9. 21 CFR 882.5300 - Methyl methacrylate for cranioplasty.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... methacrylate for cranioplasty. (a) Identification. Methyl methacrylate for cranioplasty (skull repair) is a self-curing acrylic that a surgeon uses to repair a skull defect in a patient. At the time of...

  10. (Methacrylates to form insulation). Final technical report

    SciTech Connect

    Rasmussen, L.

    1980-05-20

    The use of methacrylates to form the interior foam of a transport insulation was studied. Problems encountered with the methacrylates include its low surface tension, and its slow rate of polymerization. An additional problem was an incompatability between the fluorinated surfactant molecules and the fluorocarbon gas used to blow the foam. Other experimentation involved acrylamide foams using glycerol-ethylene glycol combinations and sodium linolenate. Also investigated was the use of tin oxide coatings which are transported to visible light but reflect infrared light. (BCS)

  11. Anionic polymerization of azo substituted methacrylates

    SciTech Connect

    Dimov, D.K.; Dalton, L.R.; Hogen-Esch, T.E.

    1993-12-31

    The anionic polymerization of 4-phenylazophenyl methacrylate (PAM) and 6-(4-phenylazophenoxy)-hexyl methacrylate (PAHM) initiated by {open_quotes}living{close_quotes} PMMA with lithium counterion was studied in THF at {minus}78{degrees}C. The polymerization of PAM was prevented by a side termination reaction. The polymerization of PAHM proceeded smoothly to furnish PMMA/azopolymer block copolymers. The process showed features typical of {open_quotes}living{close_quotes} anionic polymerization. No phase transitions could be detected by DSC to prove liquid crystalline mesophase formation by the block copolymers.

  12. Click synthesis of quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide with improved antibacterial and antifouling ability.

    PubMed

    Tu, Qin; Tian, Chang; Ma, Tongtong; Pang, Long; Wang, Jinyi

    2016-05-01

    A quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO-QPDMAEMA) was successfully prepared in this study via click chemistry. Alkyne-functionalized graphene oxide (GO-alkyne) was first synthesized through a two-step amidation reaction of GO-COOH. Meanwhile, azide-terminated poly(dimethylaminoethyl methacrylate) (PDMAEMA-N3) was prepared via the atom-transfer radical-polymerization of dimethylaminoethyl methacrylate (DMAEMA). Subsequently, PDMAEMA-N3 was grafted onto the GO-alkyne through click chemistry to obtain PDMAEMA modified graphene oxide (GO-PDMAEMA). Finally, the tertiary amino groups of GO-PDMAEMA were quaternized by ethyl bromide to provide a quaternized poly(dimethylaminoethyl methacrylate) functionalized graphene oxide (GO-QPDMAEMA). Various characterization techniques, including Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis spectrometry, ζ potential, Raman, contact angle analyses and field emission scanning electron microscope were used to ascertain the successful preparation of the quaternized GO-QPDMAEMA. Furthermore, antibacterial and antifouling activities of GO-QPDMAEMA were investigated via protein adsorption, as well as bacterial and cell adhesion studies. The results suggest that the GO-QPDMAEMA surface exhibited significant antibacterial and antifouling properties, compared with the GO-COOH and GO-PDMAEMA surfaces. PMID:26852103

  13. Detection of interstellar ethyl cyanide

    NASA Technical Reports Server (NTRS)

    Johnson, D. R.; Lovas, F. J.; Gottlieb, C. A.; Gottlieb, E. W.; Litvak, M. M.; Thaddeus, P.; Guelin, M.

    1977-01-01

    Twenty-four millimeter-wave emission lines of ethyl cyanide (CH3CH2CN) have been detected in the Orion Nebula (OMC-1) and seven in Sgr B2. To derive precise radial velocities from the astronomical data, a laboratory measurement of the rotational spectrum of ethyl cyanide has been made at frequencies above 41 GHz. In OMC-1, the rotational temperature of ethyl cyanide is 90 K (in good agreement with other molecules), the local-standard-of-rest radial velocity is 4.5 + or - 1.0 km/s (versus 8.5 km/s for most molecules), and the column density is 1.8 by 10 to the 14th power per sq cm (a surprisingly high figure for a complicated molecule). The high abundance of ethyl cyanide in the Orion Nebula suggests that ethane and perhaps larger saturated hydrocarbons may be common constituents of molecular clouds and have escaped detection only because they are nonpolar or only weakly polar.

  14. S-Ethyl dipropylthiocarbamate (EPTC)

    Integrated Risk Information System (IRIS)

    S - Ethyl dipropylthiocarbamate ( EPTC ) ; CASRN 759 - 94 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  15. pH-sensitive methacrylic copolymers and the production thereof

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2006-02-14

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  16. pH-sensitive methacrylic copolymers and the production thereof

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.; Bloom, Paul D.; Sheares Ashby, Valerie V.

    2007-01-09

    The present invention provides novel multi-functional methacrylic copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility under acidic conditions. The copolymers are constructed from tertiary amine methacrylates and poly(ethylene glycol) containing methacrylates. The copolymers are useful as gene vectors, pharmaceutical carriers, and in protein separation applications.

  17. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  18. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  19. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methacrylic acid-divinylbenzene copolymer. 172.775... HUMAN CONSUMPTION Other Specific Usage Additives § 172.775 Methacrylic acid-divinylbenzene copolymer. Methacrylic acid-divinylbenzene copolymer may be safely used in food in accordance with the...

  20. Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC)

    PubMed Central

    Tabatabai, Monir; Herrmann, Markus

    2016-01-01

    Summary We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by 1H NMR, IR, GPC and DSC methods. The kinetics of the deprotection step was followed by 1H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed. PMID:26977183

  1. Amino-functionalized (meth)acryl polymers by use of a solvent-polarity sensitive protecting group (Br-t-BOC).

    PubMed

    Ritter, Helmut; Tabatabai, Monir; Herrmann, Markus

    2016-01-01

    We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)acrylate) 6a,b bearing protected amino side groups. The subsequent solvolysis of the Br-t-BOC function led to the new polymers poly(2-aminoethyl (meth)acrylate) 8a,b with protonated free amino groups. The monomers and the resulting polymers were thoroughly characterized by (1)H NMR, IR, GPC and DSC methods. The kinetics of the deprotection step was followed by (1)H NMR spectroscopy. The solvent polarity and neighboring group effects on the kinetics of deprotection are discussed. PMID:26977183

  2. Discovery of (7R)-14-cyclohexyl-7-{[2-(dimethylamino)ethyl](methyl) amino}-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylic acid (MK-3281), a potent and orally bioavailable finger-loop inhibitor of the hepatitis C virus NS5B polymerase.

    PubMed

    Narjes, Frank; Crescenzi, Benedetta; Ferrara, Marco; Habermann, Jörg; Colarusso, Stefania; Ferreira, Maria del Rosario Rico; Stansfield, Ian; Mackay, Angela Claire; Conte, Immacolata; Ercolani, Caterina; Zaramella, Simone; Palumbi, Maria-Cecilia; Meuleman, Philip; Leroux-Roels, Geert; Giuliano, Claudio; Fiore, Fabrizio; Di Marco, Stefania; Baiocco, Paola; Koch, Uwe; Migliaccio, Giovanni; Altamura, Sergio; Laufer, Ralph; De Francesco, Raffaele; Rowley, Michael

    2011-01-13

    Infections caused by hepatitis C virus (HCV) are a significant world health problem for which novel therapies are in urgent demand. The polymerase of HCV is responsible for the replication of viral genome and has been a prime target for drug discovery efforts. Here, we report on the further development of tetracyclic indole inhibitors, binding to an allosteric site on the thumb domain. Structure-activity relationship (SAR) studies around an indolo-benzoxazocine scaffold led to the identification of compound 33 (MK-3281), an inhibitor with good potency in the HCV subgenomic replication assay and attractive molecular properties suitable for a clinical candidate. The compound caused a consistent decrease in viremia in vivo using the chimeric mouse model of HCV infection. PMID:21141896

  3. Anti-Bioadhesive Coating Based on Easy to Make Pseudozwitterionic RAFT Block Copolymers for Blood-Contacting Applications.

    PubMed

    Nehache, Sabrina; Yeh, Chin-Cheng; Semsarilar, Mona; Deratani, André; Chang, Yung; Quemener, Damien

    2016-01-01

    Amphiphilic diblock copolymer containing randomly distributed positive and negative charged monomers are synthesized using RAFT polymerization technique to be used as anti-bioadhesion coatings for hydrophobic surfaces. Quaternized 2-(dimethylamino) ethyl methacrylate and potassium 3-sulfopropyl methacrylate (P[qDMAEMA-co-KSPMA]) are randomly polymerized to yield an anti-bioadhesion block which is, in one pot, copolymerized with styrene as an anchoring block. This copolymer has demonstrated high anti-bioadhesion properties to avoid the blood clotting in medical devices through a simple and facile approach to preparation of pseudozwitterionic copolymers. PMID:26222768

  4. Immobilization of enzymes on 2-hydroxyethyl methacrylate and glycidyl methacrylate copolymer brushes.

    PubMed

    Ren, Tanchen; Mao, Zhengwei; Moya, Sergio Enrique; Gao, Changyou

    2014-08-01

    The immobilization of enzymes is of paramount importance to maintain their activity and stability. In this study, surface-initiated atom-transfer radical polymerization was applied to prepare poly(2-hydroxyethyl methacrylate)-block-poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) brushes on glass slides. The polymerization kinetics was followed by using a quartz crystal microbalance with dissipation monitoring and ellipsometry in terms of mass and thickness growth, respectively. The surface chemical compositions of the obtained polymer brushes were characterized by X-ray photoelectron spectroscopy. Their mass, thickness, and enzyme-immobilization ability could be easily tuned by the initiator reaction time, monomer ratio, and polymerization time. The antibacterial activity and stability of the immobilized lysozymes were studied by fluorescent staining and bacteria lysis assay, which revealed that the lysozymes on the copolymer brushes had good stability during storage at 4 °C for up to 30 days. PMID:24962678

  5. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, Box... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and....1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH. (b) The ingredient meets...

  6. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  7. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  8. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  9. 21 CFR 184.1293 - Ethyl alcohol.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl alcohol. 184.1293 Section 184.1293 Food and... Substances Affirmed as GRAS § 184.1293 Ethyl alcohol. (a) Ethyl alcohol (ethanol) is the chemical C2H5OH....

  10. Hydrogenation of ethyl 5-cyano-2-oximinovalerate

    SciTech Connect

    Klabunovskii, E.I.; Levitina, E.S.; Kaigorodova, L.N.; Godunova, L.F.; Gogoladze, D.D.; Karpeiskaya, E.I.; Novikova, S.A.

    1987-03-10

    Hydrogenation of ethyl 5-cyano-2-oximinovalerate in acetic anhydride at atmospheric pressure in the presence of strong base leads to a quantitative yield of the ethyl ester of ..cap alpha..,eta-diacetyllysine. Selective reduction of the cyano and oximino groups in ethyl 5-cyano-2-oximinovalerate has been shown in the presence of powdered Ni, Cu-Ni, and LaNi/sub 5/H/sub 6.6/ catalysts. Hydrogenation of ethyl 5-cyano-2-oximinovalerate on Raney Ni at atmospheric pressure in dioxan with addition of acetic anhydride leads to a 50% yield of diacetyllysine.

  11. Zwitterionic Poly(amino acid methacrylate) Brushes

    PubMed Central

    2014-01-01

    A new cysteine-based methacrylic monomer (CysMA) was conveniently synthesized via selective thia-Michael addition of a commercially available methacrylate-acrylate precursor in aqueous solution without recourse to protecting group chemistry. Poly(cysteine methacrylate) (PCysMA) brushes were grown from the surface of silicon wafers by atom-transfer radical polymerization. Brush thicknesses of ca. 27 nm were achieved within 270 min at 20 °C. Each CysMA residue comprises a primary amine and a carboxylic acid. Surface zeta potential and atomic force microscopy (AFM) studies of the pH-responsive PCysMA brushes confirm that they are highly extended either below pH 2 or above pH 9.5, since they possess either cationic or anionic character, respectively. At intermediate pH, PCysMA brushes are zwitterionic. At physiological pH, they exhibit excellent resistance to biofouling and negligible cytotoxicity. PCysMA brushes undergo photodegradation: AFM topographical imaging indicates significant mass loss from the brush layer, while XPS studies confirm that exposure to UV radiation produces surface aldehyde sites that can be subsequently derivatized with amines. UV exposure using a photomask yielded sharp, well-defined micropatterned PCysMA brushes functionalized with aldehyde groups that enable conjugation to green fluorescent protein (GFP). Nanopatterned PCysMA brushes were obtained using interference lithography, and confocal microscopy again confirmed the selective conjugation of GFP. Finally, PCysMA undergoes complex base-catalyzed degradation in alkaline solution, leading to the elimination of several small molecules. However, good long-term chemical stability was observed when PCysMA brushes were immersed in aqueous solution at physiological pH. PMID:24884533

  12. Zwitterionic poly(amino acid methacrylate) brushes.

    PubMed

    Alswieleh, Abdullah M; Cheng, Nan; Canton, Irene; Ustbas, Burcin; Xue, Xuan; Ladmiral, Vincent; Xia, Sijing; Ducker, Robert E; El Zubir, Osama; Cartron, Michael L; Hunter, C Neil; Leggett, Graham J; Armes, Steven P

    2014-07-01

    A new cysteine-based methacrylic monomer (CysMA) was conveniently synthesized via selective thia-Michael addition of a commercially available methacrylate-acrylate precursor in aqueous solution without recourse to protecting group chemistry. Poly(cysteine methacrylate) (PCysMA) brushes were grown from the surface of silicon wafers by atom-transfer radical polymerization. Brush thicknesses of ca. 27 nm were achieved within 270 min at 20 °C. Each CysMA residue comprises a primary amine and a carboxylic acid. Surface zeta potential and atomic force microscopy (AFM) studies of the pH-responsive PCysMA brushes confirm that they are highly extended either below pH 2 or above pH 9.5, since they possess either cationic or anionic character, respectively. At intermediate pH, PCysMA brushes are zwitterionic. At physiological pH, they exhibit excellent resistance to biofouling and negligible cytotoxicity. PCysMA brushes undergo photodegradation: AFM topographical imaging indicates significant mass loss from the brush layer, while XPS studies confirm that exposure to UV radiation produces surface aldehyde sites that can be subsequently derivatized with amines. UV exposure using a photomask yielded sharp, well-defined micropatterned PCysMA brushes functionalized with aldehyde groups that enable conjugation to green fluorescent protein (GFP). Nanopatterned PCysMA brushes were obtained using interference lithography, and confocal microscopy again confirmed the selective conjugation of GFP. Finally, PCysMA undergoes complex base-catalyzed degradation in alkaline solution, leading to the elimination of several small molecules. However, good long-term chemical stability was observed when PCysMA brushes were immersed in aqueous solution at physiological pH. PMID:24884533

  13. On permeability of methyl methacrylate, 2-hydroxyethyl methacrylate and triethyleneglycol dimethacrylate through protective gloves in dentistry.

    PubMed

    Andreasson, Harriet; Boman, Anders; Johnsson, Stina; Karlsson, Stig; Barregård, Lars

    2003-12-01

    Continuous glove use is more common in dentistry than in most other occupations, and the glove should offer protection against blood-borne infections, skin irritants and contact allergens. Methacrylate monomers are potent contact allergens, and it is known that these substances may penetrate the glove materials commonly used. The aim of this study was to assess the permeability of various types of gloves to methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and triethyleneglycol dimethacrylate (TEGDMA) with special reference to combinations with ethanol or acetone. The permeation rate and time lag breakthrough (lag-BT) for MMA (neat, or diluted to 30% in ethanol or acetone), HEMA (30% in water, ethanol, or acetone) and TEGDMA (30% in ethanol or acetone) were investigated for different protective gloves. Nine different types of gloves were tested for one or several of these methacrylates. The lag-BT for neat MMA was

  14. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  15. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted methyl styrene, methyl methacrylate, and substituted silane. 721.6920 Section 721.6920 Protection... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  17. Injectible bodily prosthetics employing methacrylic copolymer gels

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-02-27

    The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

  18. Microgel colloidosomes based on pH-responsive poly(tert-butylaminoethyl methacrylate) latexes.

    PubMed

    Morse, Andrew J; Madsen, Jeppe; Growney, David J; Armes, Steven P; Mills, Peter; Swart, Ron

    2014-10-28

    Emulsion copolymerization of 2-(tert-butylamino)ethyl methacrylate (TBAEMA) with divinylbenzene (DVB) cross-linker in the presence of monomethoxy-capped poly(ethylene glycol) methacrylate (PEGMA) at 70 °C afforded sterically stabilized poly[2-(tert-butylamino)ethyl methacrylate] (PTBAEMA) latexes at 10% solids at pH 9. Such particles proved to be an effective Pickering emulsifier at pH 10 for both n-dodecane and n-hexane. (1)H NMR spectroscopy was used to follow the model reaction between the secondary amine of the TBAEMA monomer and the isocyanate groups of tolylene 2,4-diisocyanate-terminated poly(propylene glycol) (PPG-TDI). Cross-linking the PTBAEMA latex particles adsorbed at the n-dodecane/water interface using this oil-soluble PPG-TDI cross-linker at around 0 (o)C led to robust colloidosomes that survived an acid challenge. This resistance to demulsification was confirmed via laser diffraction studies following an in situ switch from pH 10 to 3, since no change was observed in either the oil droplet size or concentration (compared to non-cross-linked PTBAEMA-stabilized Pickering emulsions). Such PTBAEMA colloidosomes survived removal of the internal oil phase on washing with excess ethanol. However, because ethanol is a good solvent for the PTBAEMA chains, imaging the ethanol-treated colloidosomes via electron microscopy proved rather problematic due to partial film formation. Therefore, a series of TBAEMA/styrene copolymer latexes (comprising 10, 30, 50, or 60 mol % styrene) were prepared via emulsion copolymerization at 70 °C in the presence of DVB and PEGMA. The higher glass transition temperatures exhibited by these copolymer particles (and their greater resistance to ethanol swelling) enabled better-quality electron microscopy images to be obtained. The presence of nitrogen atoms at the surface of these copolymer latex particles was confirmed via X-ray photoelectron spectroscopy studies; these secondary amine groups allow covalent cross-linking via

  19. Methacrylic resin having a high solar radiant energy absorbing property and process for producing the same

    SciTech Connect

    Abe, K.; Kamada, K.; Nakai, Y.

    1981-10-20

    A methacrylic resin having a high solar radiant energy absorbing property wherein an organic compound (A) containing cupric ion and a compound (B) having at least one p-o-h bond in a molecule are contained into the methacrylic resin selected from poly(Methyl methacrylate) or methacrylic polymers containing at least 50% by weight of a methyl methacrylate unit. A process for producing said methacrylic resin is also disclosed.

  20. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  1. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  2. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  3. 21 CFR 573.420 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.420 Ethyl cellulose. The food additive ethyl cellulose may be safely used in animal feed in accordance with the following prescribed conditions: (a) The food additive is a cellulose ether...

  4. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  5. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.868 Ethyl...

  6. 21 CFR 172.868 - Ethyl cellulose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl cellulose. 172.868 Section 172.868 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.868 Ethyl...

  7. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  8. 21 CFR 173.228 - Ethyl acetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the specifications of the Food Chemicals Codex, 1 (Ethyl Acetate; p. 372, 3d Ed., 1981), which are... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl acetate. 173.228 Section 173.228 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  9. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  10. 27 CFR 21.108 - Ethyl ether.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL FORMULAS FOR DENATURED ALCOHOL AND RUM Specifications for Denaturants § 21.108 Ethyl ether. (a) Odor. Characteristic odor....

  11. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  12. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  13. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  14. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  15. 40 CFR 721.10053 - Alkyl silane methacrylate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl silane methacrylate (generic... Specific Chemical Substances § 721.10053 Alkyl silane methacrylate (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as alkyl...

  16. DEGRADATION OF POLY(METHYL METHACRYLATE) IN SOLUTION

    EPA Science Inventory

    The rate of degradation of poly(methyl methacrylate) (PMMA) to methyl methacrylate (MMA) was investigated in the liquid phase with toluene as the solvent. The degradation experiments were carried out in a tubular flow reactor at 1000 psig (6.8 MPa) and at four different temperat...

  17. Regioselective ester cleavage during the preparation of bisphosphonate methacrylate monomers

    PubMed Central

    Chougrani, Kamel; Niel, Gilles; Boutevin, Bernard

    2011-01-01

    Summary New functional monomers bearing a methacrylate, a bisphosphonate function and, for most, an internal carboxylate group, were prepared for incorporation into copolymers with adhesive or anticorrosive properties. Methanolysis of some trimethylsilyl bisphosphonate esters not only deprotects the desired bisphosphonate function but also regioselectively cleaves the alkyl ester function without affecting the methacrylate ester. PMID:21512600

  18. Cell-laden microengineered gelatin methacrylate hydrogels.

    PubMed

    Nichol, Jason W; Koshy, Sandeep T; Bae, Hojae; Hwang, Chang M; Yamanlar, Seda; Khademhosseini, Ali

    2010-07-01

    The cellular microenvironment plays an integral role in improving the function of microengineered tissues. Control of the microarchitecture in engineered tissues can be achieved through photopatterning of cell-laden hydrogels. However, despite high pattern fidelity of photopolymerizable hydrogels, many such materials are not cell-responsive and have limited biodegradability. Here, we demonstrate gelatin methacrylate (GelMA) as an inexpensive, cell-responsive hydrogel platform for creating cell-laden microtissues and microfluidic devices. Cells readily bound to, proliferated, elongated, and migrated both when seeded on micropatterned GelMA substrates as well as when encapsulated in microfabricated GelMA hydrogels. The hydration and mechanical properties of GelMA were demonstrated to be tunable for various applications through modification of the methacrylation degree and gel concentration. The pattern fidelity and resolution of GelMA were high and it could be patterned to create perfusable microfluidic channels. Furthermore, GelMA micropatterns could be used to create cellular micropatterns for in vitro cell studies or 3D microtissue fabrication. These data suggest that GelMA hydrogels could be useful for creating complex, cell-responsive microtissues, such as endothelialized microvasculature, or for other applications that require cell-responsive microengineered hydrogels. PMID:20417964

  19. Structure/property relationships in methacrylate/dimethacrylate polymers for dental applications

    NASA Astrophysics Data System (ADS)

    Mehlem, Jeremy John

    Since its invention Bis-GMA or one of its analogs has been the main component of the polymer portion of composites for dental restorations. The need for dilution of Bis-GMA and its analogs to optimize its properties has long been recognized. Bis-GMA is a highly viscous monomer. This high viscosity leads to early vitrification, which limits conversion during cure. This viscosity also limits filler loading. Vitrification at low conversions leads to heterogeneous systems composed of low and high cross-link density phases. The low cross-link density phases behave as defects in the system; therefore, if the amount of low cross-link density phases in the system can be reduced and a more uniform network structure can be achieved, then the mechanical properties of the resin can be improved. Since the increase in viscosity during cure causes vitrification, it is logical that a system with a low initial viscosity will delay the onset of vitrification. Reactive diluents such as triethylene glycol dimethacrylate (TEGDMA) are effective at lower levels. However, large amounts negatively affect matrix properties by increasing polymerization shrinkage and water sorption. Shrinkage has been cited as one of the main deficiencies in dental composites. The goal of this project is to improve upon standard viscosity modifying comonomers such as triethylene glycol dimethacrylate. The comonomers that were explored were phenyloxyethyl methacrylate, cyclohexyl methacrylate, and tert-butylcylcohexyl methacrylate. Multicomponent systems based on analogs of ethylene glycol dimethacrylates with different length ethyl glycol chains were also examined. The substitution of monomethacrylates for TEGDMA as a comonomer resulted in enhanced or negligible affects on the mechanical properties of Bis-MEPP based polymer systems while reducing polymerization shrinkage. 129Xenon NMR and TappingMode(TM) AFM were used to characterize the heterogeneity of dimethacrylates systems during their cure cycle as well

  20. Formation and inhibition of ethyl glucuronide and ethyl sulfate.

    PubMed

    Stachel, Nicole; Skopp, Gisela

    2016-08-01

    Ethyl glucuronide (EtG) und ethyl sulfate (EtS) are widely accepted biomarkers in forensic and clinical settings. Even though, levels of EtG and EtS in blood and urine increase with increasing doses of alcohol, a high inter-individual variability in their production has been noticed. Therefore, we investigated the influence of dietary plant phenols on the formation of EtG and EtS and tentatively estimated the magnitude of in vivo inhibitory interactions from our in vitro results. To address these issues, formation of EtS and EtG was investigated using recombinant glucuronosyl- and sulfotransferases as well as human liver microsomes and liver cytosol. After respective kinetics had been established, inhibition experiments using quercetin, kaempferol and resveratrol were performed. These polyphenols are subject to extensive glucuronidation and/or sulfonation. EtG and EtS were determined by LC-MS/MS following solid phase extraction for EtG due to severe matrix effects and by direct injection for EtS. All enzymes investigated were involved in the conjugation of ethanol. Maximal EtG and EtS formation rates were observed with HLM and SULT1A1, respectively. All kinetics could best be described by Michaelis-Menten kinetics. Resveratrol was a competitive inhibitor of UGT1A1, UGT1A9 and HLM; quercetin and kaempferol were inhibitors of all transferases under investigation except UGT2B15. Findings for quercetin with regard to UGT2B7 and SULT2A1 and for kaempferol with regard to SULT1E1 and SULT2A1 suggested a mechanism based inhibition. Competitive inhibition of the glucuronidation and sulfonation of ethanol was estimated as weak to negligible and as moderate to weak, respectively. Beside the known polymorphisms of the transferases involved in EtG and EtS formation, prediction of the inhibitory potential indicates that polyphenols may contribute to the variable formation rate of EtG and EtS. PMID:26829336

  1. Improvement of holographic thermal stability in phenanthrenequinone-doped poly(methyl methacrylate-co-methacrylic acid) photopolymer

    NASA Astrophysics Data System (ADS)

    Yu, Dan; Liu, Hongpeng; Wang, Heng; Wang, Jian; Jiang, Yongyuan; Sun, Xiudong

    2011-08-01

    Experimental studies of holographic thermal stability in phenanthrenequinone (PQ)-doped poly(methyl methacrylate-co-methacrylic acid) [P(MMA-co-MAA)] photopolymers are presented. A possibility to improve the thermal stability of holograms is demonstrated by doping methacrylic acid (MAA) into the poly(methyl methacrylate) (PMMA) polymer matrix. MAA as a copolymerization monomer can form a more stable polymer matrix with methyl methacrylate (MMA) monomer and increase average molecular weight of photoproducts, which finally depress the diffusion of photoproduct. The optimized MAA concentration copolymerized into P(MMA-co-MAA) polymer matrix can bring nearly a month's lifetime of gratings, which is obviously an improvement over the usual PQ-PMMA material under thermal treatment.

  2. Predicting the chromatographic retention of polymers: poly(methyl methacrylate)s and polyacryate blends.

    PubMed

    Bashir, Mubasher A; Radke, Wolfgang

    2007-09-01

    The suitability of a retention model especially designed for polymers is investigated to describe and predict the chromatographic retention behavior of poly(methyl methacrylate)s as a function of mobile phase composition and gradient steepness. It is found that three simple yet rationally chosen chromatographic experiments suffice to extract the analyte specific model parameters necessary to calculate the retention volumes. This allows predicting accurate retention volumes based on a minimum number of initial experiments. Therefore, methods for polymer separations can be developed in relatively short time. The suitability of the virtual chromatography approach to predict the separation of polymer blend is demonstrated for the first time using a blend of different polyacrylates. PMID:17586517

  3. Preparation of ultrafine poly(methyl methacrylate-co-methacrylic acid) biodegradable nanoparticles loaded with ibuprofen.

    PubMed

    Saade, Hened; Diaz de León-Gómez, Ramón; Enríquez-Medrano, Francisco Javier; López, Raúl Guillermo

    2016-08-01

    Ibuprofen-loaded polymeric particles with around 9.2 nm in mean diameter, as determined by electron microscopy, dispersed in an aqueous media containing up to 12.8% solids were prepared by semicontinuous heterophase polymerization. The polymeric material is a (2/1 mol/mol) methyl methacrylate-co-methacrylic acid copolymer similar to Eudragit S100, deemed safe for human consumption and used in the manufacturing of drug-loaded pills as well as micro- and nanoparticles. The loading efficiency was 100%, attaining around 10-12% in drug content. Release studies showed that the drug is released from the nanoparticles at a slower rate than that in the case of free IB. Given their size as well as the pH values required for their dissolution, it is believed that this type of particles could be used as a basis for preparing nanosystems loaded with a variety of drugs. PMID:27126476

  4. Fate of methyl methacrylate in rats.

    PubMed Central

    Bratt, H.; Hathway, D. E.

    1977-01-01

    Up to 88% of a single dose of methyl[14C]methacrylate in rats is expired as 14CO2 in 10 days (65% in 2 h), irrespective of the route of administration and of the specific labelling of the propylene residue of the molecule. The implications of this observation, and of the excretion of small amounts of [14C]methylmalonate, [14C]-succinate and probably of [14C]beta-hydroxyisobutyrate and 2-formylpropionate, and of the formation of [14C] normal, physiological metabolites that may be accounted for by anabolism both from 14CO2 and from [14C]acetate emergent from the citric acid cycle, are that the metabolic pathway concerned involves intermediary metabolism and relates to mitochondrial function. Present findings are discussed in relation to the imputations of a report of carcinogenic risk. PMID:889678

  5. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, L.A. Jr.; Arganbright, R.P.; Hearn, D.

    1995-12-19

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50 C to 300 C, using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered. 2 figs.

  6. Process for the preparation of ethyl benzene

    DOEpatents

    Smith, Jr., Lawrence A.; Arganbright, Robert P.; Hearn, Dennis

    1995-01-01

    Ethyl benzene is produced in a catalyst bed under 0.25 to 50 atmospheres of pressure and at temperatures in the range of 50.degree. C. to 300.degree. C., using as the catalyst a mole sieve characterized as acidic by feeding ethylene to the catalyst bed while benzene is conveniently added through the reflux to result in a molar excess present in the reactor to that required to react with ethylene, thereby reacting substantially all of the ethylene and recovering benzene as the principal overhead and ethyl benzene and diethyl benzene in the bottoms. The bottoms are fractionated, the ethyl benzene recovered and the bottoms are contacted with benzene in the liquid phase in a fixed bed straight pass reactor under conditions to transalkylate the benzene thereby converting most of the diethyl benzene to ethyl benzene which is again separated and recovered.

  7. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... of concentrated sulfuric acid. Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of...

  8. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of the “Food Chemicals Codex,” 3d...

  9. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of concentrated sulfuric acid. Ethyl formate occurs naturally in some plant oils, fruits, and juices but does not occur naturally in the animal kingdom. (b) The ingredient meets the specifications of...

  10. Biocompatible Bacterial Cellulose-Poly(2-hydroxyethyl methacrylate) Nanocomposite Films

    PubMed Central

    Figueiredo, Andrea G. P. R.; Figueiredo, Ana R. P.; Alonso-Varona, Ana; Fernandes, Susana C. M.; Palomares, Teodoro; Rubio-Azpeitia, Eva; Barros-Timmons, Ana; Silvestre, Armando J. D.; Pascoal Neto, Carlos; Freire, Carmen S. R.

    2013-01-01

    A series of bacterial cellulose-poly(2-hydroxyethyl methacrylate) nanocomposite films was prepared by in situ radical polymerization of 2-hydroxyethyl methacrylate (HEMA), using variable amounts of poly(ethylene glycol) diacrylate (PEGDA) as cross-linker. Thin films were obtained, and their physical, chemical, thermal, and mechanical properties were evaluated. The films showed improved translucency compared to BC and enhanced thermal stability and mechanical performance when compared to poly(2-hydroxyethyl methacrylate) (PHEMA). Finally, BC/PHEMA nanocomposites proved to be nontoxic to human adipose-derived mesenchymal stem cells (ADSCs) and thus are pointed as potential dry dressings for biomedical applications. PMID:24093101

  11. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .../methyl methacrylate polymers. The vinylidene chloride/methyl acrylate/methyl methacrylate polymers (CAS... methacrylate polymers consist of basic polymers produced by the copolymerization of vinylidene chloride/methyl acrylate/methyl methacrylate such that the basic polymers or the finished food-contact articles meet...

  12. Multi-steps green process for synthesis of six-membered functional cyclic carbonate from trimethylolpropane by lipase catalyzed methacrylation and carbonation, and thermal cyclization.

    PubMed

    Sayed, Mahmoud; Gaber, Yasser; Bornadel, Amin; Pyo, Sang-Hyun

    2016-01-01

    A highly functionalized six-membered cyclic carbonate, methacrylated trimethylolpropane (TMP) cyclic carbonate, which can be used as a potential monomer for bisphenol-free polycarbonates and isocyanate-free polyurethanes, was synthesized by two steps transesterifications catalyzed by immobilized Candida antarctica lipase B, Novozym(®) 435 (N435) followed by thermal cyclization. TMP was functionalized as 70 to 80% selectivity of mono-methacrylate with 70% conversion was achieved, and the reaction rate was evaluated using various acyl donors such as methacrylic acid, methacrylate-methyl ester, -ethyl ester, and -vinyl ester. As a new observation, the fastest rate obtained was for the transesterfication reaction using methacrylate methyl ester. Byproducts resulted from leaving groups were adsorbed on the molecular sieves (4Å) to minimize the effect of leaving group on the equilibrium. The difference of reaction rate was explained by molecular dynamic simulations on interactions between carbonyl oxygen and amino acid residues (Thr 40 and Glu 157) in the active site of lipase. Our docking studies revealed that as acyl donor, methyl ester was preferred for the initial conformation of the first tetrahederal intermediate with hydrogen bonding interactions. TMP-monomethacrylate (TMP-mMA) cyclic carbonate was obtained in 63% yield (74.1% calculated in 85% conversion) from the lipase-catalyzed carbonation reaction of TMP-mMA with dimethylcarbonate, and followed by thermal cyclization of the monocarbonate at 90°C. From the multiple reactions demonstrated in gram scale, TMP-mMA cyclic carbonate was obtained as a green process without using chlorinated solvent and reagent. PMID:26561375

  13. HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR METHYL METHACRYLATE

    EPA Science Inventory

    The Health and Environmental Effects Profile for methyl methacrylate was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response to support listings of hazardo...

  14. Thermoresponsive amperometric glucose biosensor.

    PubMed

    Pinyou, Piyanut; Ruff, Adrian; Pöller, Sascha; Barwe, Stefan; Nebel, Michaela; Alburquerque, Natalia Guerrero; Wischerhoff, Erik; Laschewsky, André; Schmaderer, Sebastian; Szeponik, Jan; Plumeré, Nicolas; Schuhmann, Wolfgang

    2016-03-01

    The authors report on the fabrication of a thermoresponsive biosensor for the amperometric detection of glucose. Screen printed electrodes with heatable gold working electrodes were modified by a thermoresponsive statistical copolymer [polymer I: poly(ω-ethoxytriethylenglycol methacrylate-co-3-(N,N-dimethyl-N-2-methacryloyloxyethyl ammonio) propanesulfonate-co-ω-butoxydiethylenglycol methacrylate-co-2-(4-benzoyl-phenoxy)ethyl methacrylate)] with a lower critical solution temperature of around 28 °C in aqueous solution via electrochemically induced codeposition with a pH-responsive redox-polymer [polymer II: poly(glycidyl methacrylate-co-allyl methacrylate-co-poly(ethylene glycol)methacrylate-co-butyl acrylate-co-2-(dimethylamino)ethyl methacrylate)-[Os(bpy)2(4-(((2-(2-(2-aminoethoxy)ethoxy)ethyl)amino)methyl)-N,N-dimethylpicolinamide)](2+)] and pyrroloquinoline quinone-soluble glucose dehydrogenase acting as biological recognition element. Polymer II bears covalently bound Os-complexes that act as redox mediators for shuttling electrons between the enzyme and the electrode surface. Polymer I acts as a temperature triggered immobilization matrix. Probing the catalytic current as a function of the working electrode temperature shows that the activity of the biosensor is dramatically reduced above the phase transition temperature of polymer I. Thus, the local modulation of the temperature at the interphase between the electrode and the bioactive layer allows switching the biosensor from an on- to an off-state without heating of the surrounding analyte solution. PMID:26702635

  15. 40 CFR 721.10595 - Octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Octadecen-1-aminium, N-ethyl-N,N... Significant New Uses for Specific Chemical Substances § 721.10595 Octadecen-1-aminium, N-ethyl-N,N-dimethy... chemical substance identified as octadecen-1-aminium, N-ethyl-N,N-dimethy-, ethyl sulfate (1:1) (PMN...

  16. The Competing Effects of Hyaluronic and Methacrylic Acid in Model Contact Lenses.

    PubMed

    Weeks, Andrea; Subbaraman, Lakshman N; Jones, Lyndon; Sheardown, Heather

    2012-01-01

    The aim of this study was to determine the influence of hyaluronic acid (HA) on lysozyme sorption in model contact lenses containing varying amounts of methacrylic acid (MAA). One model conventional hydrogel (poly(2-hydroxyethyl methacrylate) (pHEMA)) and two model silicone hydrogels (pHEMA, methacryloxypropyltris(trimethylsiloxy)silane (pHEMA TRIS) and N,N-dimethylacrylamide, TRIS (DMAA TRIS)) lens materials were prepared with and without MAA at two different concentrations (1.7 and 5%). HA, along with dendrimers, was loaded into these model contact lens materials and then cross-linked with 1-ethyl-3-(3-dimethylamino propyl)-carbodiimide (EDC). Equilibrium water content (EWC), advancing water contact angle and lysozyme sorption on these lens materials were investigated. In the HA-containing materials, the presence (P < 0.05) and amount (P < 0.05) of MAA increased the EWC of the materials. For most materials, addition of MAA reduced the advancing contact angles (P < 0.05) and for all the materials, the addition of HA further improved hydrophilicity (P < 0.05). For the non-HA containing hydrogels, the presence (P < 0.05) and amount (P < 0.05) of MAA increased lysozyme sorption. The presence of HA decreased lysozyme sorption for all materials (P < 0.05). MAA appears to work synergistically with HA to increase the EWC in addition to improving the hydrophilicity of model pHEMA-based and silicone hydrogel contact lens materials. Hydrogel materials that contain HA have tremendous potential as hydrophilic, protein-resistant contact lens materials. PMID:21477462

  17. Thermally Switchable Thin Films of an ABC Triblock Copolymer of Poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate)

    SciTech Connect

    Zhang, Shanju; Liu, Zhan; Bucknall, David G.; He, Lihong; Hong, Kunlun; Mays, Jimmy; Allen, Mark

    2011-01-01

    The thermo-responsive behavior of polymer films consisting of novel linear triblock copolymers of poly(n-butyl methacrylate)-poly(methyl methacrylate)-poly(2-fluoroethyl methacrylate) (PnBuMA-PMMA-P2FEMA) are reported using differential scanning calorimetry (DSC), atomic forcing microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contacting angle (CA) measurements. The surface morphology, wettability and chemical structure of thin films of these triblock copolymers on silicon wafers as a function of temperature have been investigated. It has been shown that the wettability of the films is thermally switchable. Detailed structural analysis shows that thermo-responsive surface composition changes are produced. The underlying mechanism of the thermoresponsive behavior is discussed.

  18. Furfuryl methacrylate plasma polymers for biomedical applications.

    PubMed

    Shirazi, Hanieh Safizadeh; Rogers, Nicholas; Michelmore, Andrew; Whittle, Jason D

    2016-01-01

    Furfuryl methacrylate (FMA) is a promising precursor for producing polymers for biomedical and cell therapy applications. Herein, FMA plasma polymer coatings were prepared with different powers, deposition times, and flow rates. The plasma polymer coatings were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results from AFM and SEM show the early growth of the coatings and the existence of particle aggregates on the surfaces. XPS results indicated no measureable chemical differences between the deposited films produced under different power and flow rate conditions. ToF-SIMS analysis demonstrated differing amounts of C5H5O (81 m/z) and C10H9O2 (161 m/z) species in the coatings which are related to the furan ring structure. Through judicious choice of plasma polymerization parameters, the quantity of the particle aggregates was reduced, and the fabricated plasma polymer coatings were chemically uniform and smooth. Primary human fibroblasts were cultured on FMA plasma polymer surfaces to determine the effect of surface chemical composition and the presence of particle aggregates on cell culture. Particle aggregates were shown to inhibit fibroblast attachment and proliferation. PMID:27609095

  19. [Degradation of thiometon in ethyl acetate].

    PubMed

    Satoh, M; Shimokawa, S; Kobata, M; Tanaka, T; Nakanishi, Y

    2001-04-01

    When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 microL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate. The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton. These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton. PMID:11486375

  20. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  1. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  2. 40 CFR 721.10244 - Phosphonic acid, P-[2-[bis(2-hydroxyethyl)amino]ethyl]-, 2-[bis(2- chloroethoxy)phosphinyl]ethyl...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphonic acid, P- ethyl]-, 2- ethyl... New Uses for Specific Chemical Substances § 721.10244 Phosphonic acid, P- ethyl]-, 2- ethyl 2... substance identified as phosphonic acid, P- ethyl]-, 2- ethyl 2-chloroethyl ester (PMN P-09-195; CAS...

  3. Preparation and application of sol-gel acrylate and methacrylate solid-phase microextraction fibres for gas chromatographic analysis of organoarsenic compounds.

    PubMed

    Popiel, Stanisław; Nawała, Jakub; Czupryński, Krzysztof

    2014-07-21

    Novel solid-phase microextraction (SPME) fibres containing methyl, ethyl, butyl acrylate and methacrylate were first prepared by a sol-gel technique and investigated for determination of selected organoarsenic compounds (lewisite, methyldichloroarsine, phenyldichloroarsine, diphenylchloroarsine and triphenylarsine) from water samples. The influence of sorption and desorption temperature and time for extraction efficiency were examined. The best new fibre coatings (methyl acrylate (MA), methyl methacrylate (MMA) and combination of methyl acrylate and methacrylate (MA/MMA)) for analysis of organoarsenic compounds were selected and compared with commercial fibres. The distribution coefficients Kfs were determined for the best novel fibres and for absorption commercial fibres. The highest Kfs value were obtained for MA/MMA and MMA fibres and were respectively 9458 and 6561 for lewisite and 6458 and 5884 for triphenylarsine. The limit of detection and quantification were determined for the three laboratory obtained fibres (MA, MMA and MA/MMA). LODs for tested fibres, at a signal-to-noise of 3, were 0.03-0.3 ng mL(-1). LOQs for selected coatings, at signal-to-noise of 10, were 0.1-0.8 ng mL(-1). The relative standard deviations (RSD) for all measurements were 4.3-6.5% (n=9) and relative errors were 2.5-5%. The laboratory obtained fibres were used for environmental analysis of pore water samples from the Baltic Sea. PMID:25000858

  4. Facile synthesis of brush poly(phosphoamidate)s via one-pot tandem ring-opening metathesis polymerization and atom transfer radical polymerization.

    PubMed

    Ding, Liang; Qiu, Jun; Wei, Jun; Zhu, Zhenshu

    2014-09-01

    Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA)-based brush poly(phosphoamidate)s are successfully synthesized by a combination of ring-opening metathesis polymerization (ROMP) and atom transfer radical polymerization (ATRP) following either a commutative two-step procedure or a straightforward one-pot process using Grubbs ruthenium-based catalysts for tandem catalysis. Compared with the traditional polymerization method, combining ROMP and ATRP in a one-pot process allows the preparation of brush copolymers characterized by a relatively moderate molecular weight distribution and quantitative conversion of monomer. Moreover, the surface morphologies and aggregation behaviors of these polymers are studied by AFM and TEM measurements. PMID:24729161

  5. Stimulus responsive drug release from polymer gel.. Controlled release of ionic drug from polyampholyte gel

    NASA Astrophysics Data System (ADS)

    Sutani, Kouichi; Kaetsu, Isao; Uchida, Kumao; Matsubara, Yoshio

    2002-07-01

    2-(Dimethylamino)ethyl methacrylate or Methacryloyloxyethyltrimethylammonium chloride as a cationic monomer was copolymerized by UV with anionic monomer such as acrylic acid (AAc), into a polyampholyte. The pH responsive swelling behaviour and the pH and electro-responsive drug release functions of polyampholyte were investigated. The result showed that a copolymer of cation rich composition swelled at acidic condition, and shrank at alkaline condition. On the other hand, an anion rich copolymer showed a reverse phenomenon. Polyampholyte proved to interact with an ionic drug both by ionic binding and physical adsorption.

  6. Biomimetic silica nanostructures on the surface, controlled by polyvalent counteranions

    NASA Astrophysics Data System (ADS)

    Yang, Sung Ho

    2013-09-01

    Biosilicification (silica biomineralization in diatoms) has been intensively investigated for the in vitro formation of inorganic nanostructures under the ambient condition. It is known that biosilicification occurs at the interface of catalytic templates, derived by interactions between cationic polyamines and anions. In this work, nanostructures of silica thin films were controlled by exchanging counteranions of quaternized poly(2-(dimethylamino)ethyl methacrylate) with orthophosphate/pyrophosphate anions such as HPO4-, HPO42-, PO43- and PO74-. Thickness of silica films and diameters of silica nanoparticulates were tuned at the nanometer scale. In addition, it was found that resulted silica structure highly depended on the structure of catalytic polymeric templates.

  7. A knot polymer mediated non-viral gene transfection for skin cells.

    PubMed

    Cutlar, Lara; Gao, Yongsheng; Aied, Ahmed; Greiser, Udo; Murauer, Eva Maria; Zhou, Dezhong; Wang, Wenxin

    2016-01-01

    A knot polymer, poly[bis(2-acryloyl)oxyethyl disulphide-co-2-(dimethylamino) ethyl methacrylate] (DSP), was synthesized, optimized and evaluated as a non-viral vector for gene transfection for skin cells, keratinocytes. With recessive dystrophic epidermolysis bullosa keratinocytes (RDEBK-TA4), the DSP exhibited high transfection efficacy with both Gaussia luciferase marker DNA and the full length COL7A1 transcript encoding the therapeutic type VII collagen protein (C7). The effective restoration of C7 in C7 null-RDEB skin cells indicates that DSP is promising for non-viral gene therapy of recessive dystrophic epidermolysis bullosa (RDEB). PMID:26369723

  8. Cationic Methacrylate Polymers as Topical Antimicrobial Agents against Staphylococcus aureus Nasal Colonization

    PubMed Central

    2015-01-01

    The in vitro and in vivo antimicrobial activity of primary ammonium ethyl methacrylate homopolymers (AEMPs) was investigated. AEMPs with different degrees of polymerization (DP = 7.7–12) were prepared by reversible addition–fragmentation chain-transfer (RAFT) polymerization. The AEMPs showed higher inhibitory effects against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), than Gram-negative bacteria. The AEMPs also showed potent anti-S. aureus activity in the presence of fetal bovine serum, whereas the activity of the antibiotic mupirocin was reduced under the same conditions. The AEMPs showed very little or no hemolytic activity. The cytotoxicity of AEMPs against mammalian cells HEp-2 and COS-7 was concentration-dependent, and the cell viability significantly decreased at higher polymer concentrations. The AEMPs significantly reduced the number of viable S. aureus cells in the nasal environment of cotton rats when compared to that of the control. This study demonstrates that AEMPs have potential for use in treating topical S. aureus infections. PMID:25010735

  9. Highly active ppm level organic copper catalyzed photo-induced ICAR ATRP of methyl methacrylate.

    PubMed

    Jiang, Xiaowu; Wu, Jian; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2014-11-01

    A novel photo-induced homogeneous atom transfer radical polymerization (ATRP) system is constructed using an organic copper salt (Cu(SC(S)N(C2 H5 )2 )2 ) as a photo-induced catalyst at 30 °C. Herein, N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA) is used as a ligand, ethyl 2-bromophenylacetate (EBPA) as an ATRP initiator, and (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TPO) as a photo-induced radical initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP using methyl methacrylate (MMA) as a modal monomer. The effect of the concentration of the organic copper on the polymerization is investigated in detail. It is found that well-controlled polymerization can be obtained even with the amount of (Cu(SC(S)N(C2 H5 )2 )2 decreasing to a 1.56 ppm level, with the molecular weight of the resultant polymers increasing linearly with monomer conversion while maintaining a narrow molecular weight distribution (M¯w/M¯n < 1.3). PMID:25250767

  10. Adsorption of doxorubicin on poly(methyl methacrylate)-chitosan-heparin-coated activated carbon beads.

    PubMed

    Miao, Jianjun; Zhang, Fuming; Takieddin, Majde; Mousa, Shaker; Linhardt, Robert J

    2012-03-01

    Extracorporeal filter cartridges, filled with an activated carbon bead (ACB) adsorbent, have been used for removal of overdosed cancer drugs from the blood. Coatings on adsorbent matrices, poly(methyl methacrylate) (PMMA)/activated carbon bead and PMMA/chitosan/heparin/ACB composites, were tested to improve their biocompatibility and blood compatibility. PMMA coating on ACBs was accomplished in a straightforward manner using a PMMA solution in ethyl acetate. A one-step hybrid coating of ACBs with PMMA-anticoagulant heparin required the use of acetone and water co-solvents. Multilayer coatings with three components, PMMA, chitosan, and heparin, involved three steps: PMMA was first coated on ACBs; chitosan was then coated on the PMMA-coated surface; and finally, heparin was covalently attached to the chitosan coating. Surface morphologies were studied by scanning electron microscopy. X-ray photoelectron spectroscopy confirmed the -SO(3)(-) group. Adsorption, of a chemotherapy drug (doxorubicin) from both water and phosphate-buffered saline, by the coated ACBs was examined. The adsorption isotherm curves were fitted using the Freundlich model. The current adsorption system might find potential applications in the removal of high-dose regional chemotherapy drugs while maintaining high efficiency, biocompatibility, and blood compatibility. PMID:22313019

  11. Cationic methacrylate polymers as topical antimicrobial agents against Staphylococcus aureus nasal colonization.

    PubMed

    Thoma, Laura M; Boles, Blaise R; Kuroda, Kenichi

    2014-08-11

    The in vitro and in vivo antimicrobial activity of primary ammonium ethyl methacrylate homopolymers (AEMPs) was investigated. AEMPs with different degrees of polymerization (DP = 7.7-12) were prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization. The AEMPs showed higher inhibitory effects against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), than Gram-negative bacteria. The AEMPs also showed potent anti-S. aureus activity in the presence of fetal bovine serum, whereas the activity of the antibiotic mupirocin was reduced under the same conditions. The AEMPs showed very little or no hemolytic activity. The cytotoxicity of AEMPs against mammalian cells HEp-2 and COS-7 was concentration-dependent, and the cell viability significantly decreased at higher polymer concentrations. The AEMPs significantly reduced the number of viable S. aureus cells in the nasal environment of cotton rats when compared to that of the control. This study demonstrates that AEMPs have potential for use in treating topical S. aureus infections. PMID:25010735

  12. Elastic electron scattering by ethyl vinyl ether

    SciTech Connect

    Khakoo, M. A.; Hong, L.; Kim, B.; Winstead, C.; McKoy, V.

    2010-02-15

    We report measured and calculated results for elastic scattering of low-energy electrons by ethyl vinyl ether (ethoxyethene), a prototype system for studying indirect dissociative attachment processes that may play a role in DNA damage. The integral cross section displays the expected {pi}{sup *} shape resonance. The agreement between the calculated and measured cross sections is generally good.

  13. Ethyl p-nitrophenyl phenylphosphorothioate (EPN)

    Integrated Risk Information System (IRIS)

    Ethyl p - nitrophenyl phenylphosphorothioate ( EPN ) ; CASRN 2104 - 64 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Ha

  14. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethyl formate. 184.1295 Section 184.1295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  15. 21 CFR 184.1295 - Ethyl formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethyl formate. 184.1295 Section 184.1295 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  16. 49 CFR 173.322 - Ethyl chloride.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation...

  17. Manufacturing Ethyl Acetate From Fermentation Ethanol

    NASA Technical Reports Server (NTRS)

    Rohatgi, Naresh K.; Ingham, John D.

    1991-01-01

    Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

  18. Striations in an ethyl alcohol glow discharge

    NASA Astrophysics Data System (ADS)

    Reyes, P. G.; Gómez, A.; Torres, C.; Martínez, H.; Castillo, F.; Vergara, J.

    2015-03-01

    This research shows the behavior of striations in glow discharge generated with high purity ethyl alcohol at a pressure of 0.6 Torr. This paper present the number of striations as a function of the of current and voltage discharge.

  19. Complex microparticulate systems based on glycidyl methacrylate and xanthan.

    PubMed

    Lungan, Maria-Andreea; Popa, Marcel; Desbrieres, Jacques; Racovita, Stefania; Vasiliu, Silvia

    2014-04-15

    Porous microparticles based on glycidyl methacrylate, dimethacrylic monomers [ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate] and xanthan gum were synthesized by aqueous suspension polymerization method in the presence of toluene as diluent using two types of initiators: benzoyl peroxide and ammonium persulfate. The G microparticles based on glycidyl methacrylate and dimethacrylic monomers and X microparticles based on glycidyl methacrylate, xanthan and dimethacrylic monomers were characterized by various techniques including FT-IR spectroscopy, TG analysis, SEM analysis and DVS method. The specific surface areas were determined by DVS method, while the copolymer porosities and pore volume were obtained from the apparent and skeletal densities. The results have indicated that xanthan was included in the crosslinked matrix by means of covalent bonds. X microparticles have a porous structure with higher specific surface area (129-44 m(2)/g) and higher sorption capacities compared with G microparticles (69-31 m(2)/g). PMID:24607180

  20. Protonation of diethylaminoethyl methacrylate by acids in various solvents

    SciTech Connect

    Zhuravleva, I.L.; Bune, E.V.; Bogachev, Yu.S.; Sheinker, A.P.; Teleshov, E.N.

    1988-04-10

    It was established by /sup 1/H and /sup 13/C NMR that diethylaminoethyl methacrylate exists in the unprotonated form in solvents which are not acids. In the presence of an equimolar amount of hydrochloric or trifluoroacetic acids the amino ester is fully protonated, irrespective of the solvent. The diethylaminoethyl methacrylate-acetic acid system exists in the form of a molecular complex with a hydrogen bond and in the protonated form; the proportions of the protonated form were estimated in various solvents. The change in the reactivity of diethylaminoethyl methacrylate and its salts in polymerization was explained by a change in the electronic state of CH/sub 2/ = group of the monomer as a result of its protonation and of the formation of a hydrogen bond between the C = O group of the monomer and the solvent.

  1. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (generic). 721... methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (PMN P... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide,...

  2. 40 CFR 721.10523 - Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (generic). 721... methacrylate copolymer with hydroxymethyl acrylamide, vinyl chloride and long chain fatty alkyl acrylate (PMN P... Substances § 721.10523 Perfluoroalkylethyl methacrylate copolymer with hydroxymethyl acrylamide,...

  3. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  4. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare a scan from 10.5 microns...

  5. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  6. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  7. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... prescribed for polyethylene in § 177.1520. (1) Specifications—(i) Infrared identification. Ethylene-ethyl acrylate copolymers can be identified by their characteristic infrared spectra. (ii) Quantitative determination of ethyl acrylate content. The ethyl acrylate can be determined by the infrared spectra. Prepare...

  8. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  9. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  10. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combined residues of the herbicide quizalofop (2- propanoic acid) and quizalofop ethyl (ethyl-2- propanoate...) Tolerances are established for the combined residues of the herbicide quizalofop (2- propanoic acid... herbicide quizalofop-p ethyl ester , and its acid metabolite quizalofop-p , and the S enantiomers of...

  11. 40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide quizalofop ethyl, including its metabolites and degradates, in or on the....05 (2) Tolerances are established for residues of the herbicide quizalofop ethyl, including its... with regional registration are established for residues of the herbicide quizalofop ethyl,...

  12. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  13. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  14. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  15. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  16. 40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide, flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl ester], in or on the following...) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid, -phenoxy]-ethyl...

  17. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  18. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  19. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  20. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate/methyl methacrylate polymers (CAS Reg. No. 34364-83-5) identified in paragraph (a) of this section may be.../methyl acrylate/methyl methacrylate polymers consist of basic polymers produced by the...

  1. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate/methyl methacrylate polymers (CAS Reg. No. 34364-83-5) identified in paragraph (a) of this section may be.../methyl acrylate/methyl methacrylate polymers consist of basic polymers produced by the...

  2. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  3. 21 CFR 73.3121 - Poly(hydroxyethyl methacrylate)-dye copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Poly(hydroxyethyl methacrylate)-dye copolymers. 73...(hydroxyethyl methacrylate)-dye copolymers. (a) Identity. The color additives are formed by reacting one or more of the reactive dyes listed in this paragraph with poly(hydroxyethyl methacrylate), so that...

  4. 21 CFR 73.3121 - Poly(hydroxyethyl methacrylate)-dye copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Poly(hydroxyethyl methacrylate)-dye copolymers. 73...(hydroxyethyl methacrylate)-dye copolymers. (a) Identity. The color additives are formed by reacting one or more of the reactive dyes listed in this paragraph with poly(hydroxyethyl methacrylate), so that...

  5. 21 CFR 73.3127 - Vinyl alcohol/methyl methacrylate-dye reaction products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Vinyl alcohol/methyl methacrylate-dye reaction... Vinyl alcohol/methyl methacrylate-dye reaction products. (a) Identity. The color additives are formed by reacting the dyes, either alone or in combination, with a vinyl alcohol/methyl methacrylate copolymer,...

  6. Crosslinked superhydrophobic films fabricated by simply casting poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-poly(perfluorohexylethyl methacrylate) solution

    NASA Astrophysics Data System (ADS)

    Wen, Xiufang; Ye, Chao; Cai, Zhiqi; Xu, Shouping; Pi, Pihui; Cheng, Jiang; Zhang, Lijuan; Qian, Yu

    2015-06-01

    This study focuses on the preparation of superhydrophobic films by crosslinkable polymer material-Poly(methyl methacrylate-butyl acrylate-hydroxyethyl methacrylate)-b-Poly(perfluorohexylethyl methacrylate) (P (MMA-BA-HEMA)-b-PFMA) with a simple one-step casting process. Nanoscale micelle particles with core-shell structure was obtained by dissolving the polymer and curing agent in the mixture of acetone and 1H, 1H, 5H octafluoropentyl-1,1,2,2 tetrafluoroethyl ether (FHT). Superhydrophobic films were fabricated by casting the micelle solution on the glass slides. By controlling the polymer concentration and acetone/FHT volume ratio, superhydrophobic polymer film with water contact angle of 153.2 ± 2.1° and sliding angle of 4° was obtained. By introducing a curing agent into the micelle solution, mechanical properties of the films can be improved. The adhension grade and hardness of the crosslinked superhydrophobic films reached 2 grade and 3H, respectively. The hydrophobicity is attributed to the synergistic effect of micro-submicro-nano-meter scale roughness by nanoscale micelle particles and low surface energy of fluoropolymer. This procedure makes it possible for widespread applications of superhydrophobic film due to its simplicity and practicability.

  7. 40 CFR 721.10619 - Perfluoroalkylethyl methacrylate copolymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... as perfluoroalkylethyl methacrylate copolymer (PMN P-11-653) is subject to reporting under this.... Requirements as specified in § 721.80(p)(any amount after September 30, 2014). (b) Specific requirements. The...) Recordkeeping. Recordkeeping requirements as specified in § 721.125 (a), (b), (c), (f), (h), and (i)...

  8. Synthesis of acrylates and methacrylates from coal-derived syngas

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L.

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  9. 21 CFR 172.775 - Methacrylic acid-divinylbenzene copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Methacrylic acid-divinylbenzene copolymer. 172.775 Section 172.775 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD...

  10. 21 CFR 177.1830 - Styrene-methyl methacrylate copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Styrene-methyl methacrylate copolymers. 177.1830 Section 177.1830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and...

  11. Production of ethyl alcohol from bananas

    SciTech Connect

    Jones, R.L.; Towns, T.

    1983-12-01

    The production of ethyl alcohol from waste bananas presents many special problems. During cooking, matting of the latex fibers from the banana peel recongeal when cooled and left untreated. This problem has been addressed by Alfaro by the use of CaC1/sub 2/. Separation of solids prior to distillation of the mashes in an economical fashion and use of the by product are also of concern to banana processors.

  12. Synthesis of Ethyl Salicylate Using Household Chemicals

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Hur, Chinhyu; Lee, Alan; Smith, Kurt

    1996-02-01

    Ethyl salicylate is synthesized, isolated, and characterized in a three-step process using simple equipment and household chemicals. First, acetylsalicylic acid is extracted from aspirin tablets with isopropyl alcohol, then hydrolyzed to salicylic acid with muriatic acid, and finally, the salicylic acid is esterified using ethanol and a boric acid catalyst. The experiment can be directed towards high school or university level students who have sufficient background in organic chemistry to recognize the structures and reactions that are involved.

  13. Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

    NASA Astrophysics Data System (ADS)

    Kou, Jim Hwai-Cher

    In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

  14. Computer assisted modeling of ethyl sulfate pharmacokinetics.

    PubMed

    Schmitt, Georg; Halter, Claudia C; Aderjan, Rolf; Auwaerter, Volker; Weinmann, Wolfgang

    2010-01-30

    For 12 volunteers of a drinking experiment the concentration-time-courses of ethyl sulfate (EtS) and ethanol were simulated and fitted to the experimental data. The concentration-time-courses were described with the same mathematical model as previously used for ethyl glucuronide (EtG). The kinetic model based on the following assumptions and simplifications: a velocity constant k(form) for the first order formation of ethyl sulfate from ethanol and an exponential elimination constant k(el). The mean values (and standard deviations) obtained for k(form) and k(el) were 0.00052 h(-1) (0.00014) and 0.561 h(-1) (0.131), respectively. Using the ranges of these parameters it is possible to calculate minimum and maximum serum concentrations of EtS based on stated ethanol doses and drinking times. The comparison of calculated and measured concentrations can prove the plausibility of alleged ethanol consumption and add evidence to the retrospective calculation of ethanol concentrations based on EtG concentrations. PMID:19913378

  15. The binding of ethyl isocyanide to ferroperoxidase

    PubMed Central

    Phelps, Charles; Antonini, Eraldo; Brunori, Maurizio

    1972-01-01

    The equilibrium and kinetics of ethyl isocyanide binding to ferroperoxidase were studied. At pH9.1 the results of both studies are consistent with a single-process model with an affinity constant of 95m−1 and combination and dissociation constants of 2.2×103m−1·s−1 and 23s−1 respectively. Ethyl isocyanide is not bound significantly at pH values lower than 6.0, and in this behaviour and the pH-dependence of the affinity constant, similarities exist between isocyanide and cyanide binding. The enthalpy of the process measured by equilibrium methods is −59kJ/mol (−14kcal/mol). At pH values below 9, the ethyl isocyanide adduct changes in a slow time-dependent manner, giving rise to a new species. These changes are reversible on increasing the pH. The results are discussed in relation to other known information about ligand binding to ferroperoxidase and to myoglobin. PMID:5084796

  16. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  17. 40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates (salts). 721.3152 Section 721... Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl sulfates... ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...

  18. Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.

    PubMed

    Cataldo, Franco

    2013-01-01

    Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C≈1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C≈1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (≈243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value. PMID:23969233

  19. A novel crosslinker for UV copolymerization of N-vinyl pyrrolidone and methacrylates

    SciTech Connect

    Lai, Yu-Chin

    1993-12-31

    Methacryloxyethyl vinyl carbonate, a novel crosslinker containing a vinyl carbonate and a methacrylate group which is capable of copolymerizing N-vinyl pyrrolidone and methacrylates, was prepared. With this crosslinker, N-vinyl pyrrolidone and methacrylates can copolymerize efficiently under strictly UV condition. Previously, polymeric systems containing N-vinyl pyrrolidone and methacrylates were prepared using thermal initiators, or a combination of thermal and UV initiators in the presence of crosslinkers such as allyl methacrylate or ethylene glycol dimethacrylate, These processes often led to polymers with inferior properties and less controllable quality. The use of this novel crosslinker represents a sharp improvement in polymerization conditions (UV vs heat) as well as product quality.

  20. Aminated poly(glycidyl methacrylate)s for constructing efficient gene carriers.

    PubMed

    Dou, X B; Chai, M Y; Zhu, Y; Yang, W T; Xu, F J

    2013-04-24

    Aminated poly(glycidyl methacrylate) (PGMA) vectors could efficiently mediate gene delivery. Recently, we reported that ethanolamine (EA)-functionalized PGMA could provide high transfection efficiency, while exhibiting very low toxicity. Herein, different amine species, including 1-amino-2-propanol (AP1), 3-amino-2-propanol (AP2), EA, and N,N,-dimethylethylenediamine (DED), and its quaternized DED, were proposed to aminate PGMA. The DNA condensation abilities, pH buffering capacities, cytotoxicities, and gene transfection efficiencies of the resultant aminated PGMA vectors were systematically compared. Compared with EA, AP1 (or AP2) contains an additional methyl (or methylene) group. EA-, AP1-, and AP2-functionalized PGMA vectors exhibited similar condensation abilities. The methyl (from AP1) and methylene (from AP2) species could benefit the gene delivery. The transfection performance mediated by AP1-functionalized PGMA is best. DED possesses a tertiary amine group, which could be quaternized to further enhance the DNA condensation ability of aminated PGMA. No obvious increase in cytotoxicity of quaternized DED-aminated PGMA was observed. But both DED- and its quaternized counterpart-functionalized PGMA vectors exhibited very low pH buffering capacities, making them exhibit poor gene transfection performances. The current study would provide useful information for constructing better PGMA-based delivery systems with good biophysical properties. PMID:23514579

  1. Multiple headspace solid-phase microextraction using a new fiber for avoiding matrix interferences in the quantitative determination of ethyl carbamate in pickles.

    PubMed

    Lei, Fen-Fen; Zhang, Xue-Na; Gao, Yuan-Li; Han, Ya-Hong; Li, Xiu-Juan; Pan, Si-Yi

    2012-05-01

    Multiple headspace solid-phase microextraction (HS-SPME) using a novel fiber coated with anilino-methyl triethoxy silicane-methacrylic acid/terminated silicone oil has been introduced as a useful pretreatment technique coupled to gas chromatography-flame ionization detector for the detection of ethyl carbamate in pickles. Anilino-methyl triethoxy silicane and methacrylic acid are put into use simultaneously with the aim to increase the hydrogen interaction strength between ethyl carbamate and the coating. In addition, the new fiber exhibits high thermal stability, good reproducibility, and long lifetime. Extraction temperature, extraction time, amount of desiccant, and amount of sample were well optimized to guarantee the suitability of multiple HS-SPME. Significant matrix interference was observed among various types of pickles and the multiple HS-SPME procedure was proved to be effective in avoiding the matrix effect by a complete recovery of the analyte. The method showed satisfactory linearity (0.1-100 mg kg(-1)), precision (4.25%, n = 5), and detection limit (0.038 mg kg(-1)). The accuracy of the method was evaluated by comparison with standard addition method and the results were statistically equivalent. The study indicates that the multiple HS-SPME procedure is simple, convenient, accurate, and low-cost, and most of all, can be used for quantitative analysis in complex matrix without matrix effect. PMID:22689492

  2. Optimization of ethyl ester production assisted by ultrasonic irradiation.

    PubMed

    Noipin, K; Kumar, S

    2015-01-01

    This study presents the optimization of the continuous flow potassium hydroxide-catalyzed synthesis of ethyl ester from palm oil with ultrasonic assistance. The process was optimized by application of factorial design and response surface methodology. The independent variables considered were ethanol to oil molar ratio, catalyst concentration, reaction temperature and ultrasonic amplitude; and the response was ethyl ester yield. The results show that ethanol to oil molar ratio, catalyst concentration, and ultrasonic amplitude have positive effect on ethyl ester yield, whereas reaction temperature has negative influence on ethyl ester yield. Second-order models were developed to predict the responses analyzed as a function of these three variables, and the developed models predicts the results in the experimental ranges studied adequately. This study shows that ultrasonic irradiation improved the ethyl ester production process to achieve ethyl ester yields above 92%. PMID:25116594

  3. Polymethyl methacrylate (PMMA)-bismuth ferrite (BFO) nanocomposite: low loss and high dielectric constant materials with perceptible magnetic properties.

    PubMed

    Tamboli, Mohaseen S; Palei, Prakash K; Patil, Santosh S; Kulkarni, Milind V; Maldar, Noormahmad N; Kale, Bharat B

    2014-09-21

    Herein, poly(methyl methacrylate)-bismuth ferrite (PMMA-BFO) nanocomposites were successfully prepared by an in situ polymerization method for the first time. Initially, the as prepared bismuth ferrite (BFO) nanoparticles were dispersed in the monomer, (methyl methacrylate) by sonication. Benzoyl peroxide was used to initiate the polymerization reaction in ethyl acetate medium. The nanocomposite films were subjected to X-ray diffraction analysis (XRD), (1)H NMR, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), infrared spectroscopy (IR), dielectric and magnetic characterizations. The dielectric measurement of the nanocomposites was investigated at a frequency range of 10 Hz to 1 MHz. It was found that the nanocomposites not only showed a significantly increased value of the dielectric constant with an increase in the loading percentage of BFO as compared to pure PMMA, but also exhibited low dielectric loss values over a wide range of frequencies. The values of the dielectric constant and dielectric loss of the PMMA-BFO5 (5% BFO loading) sample at 1 kHz frequency was found be ~14 and 0.037. The variation of the ferromagnetic response of the nanocomposite was consistent with the varying volume percentage of the nanoparticles. The remnant magnetization (Mr) and saturation magnetization (Ms) values of the composites were found to be enhanced by increasing the loading percentage of BFO. The value of Ms for PMMA-BFO5 was found to be ~6 emu g(-1). The prima facie observations suggest that the nanocomposite is a potential candidate for application in high dielectric constant capacitors. Significantly, based on its magnetic properties the composite will also be useful for use in hard disk components. PMID:25050918

  4. Investigation of Methacrylic Acid at High Pressure Using Neutron Diffraction.

    PubMed

    Marshall, William G; Urquhart, Andrew J; Oswald, Iain D H

    2015-09-10

    This article shows that pressure can be a low-intensity route to the synthesis of polymethacrylic acid. The exploration of perdeuterated methacrylic acid at high pressure using neutron diffraction reveals that methacrylic acid exhibits two polymorphic phase transformations at relatively low pressures. The first is observed at 0.39 GPa, where both phases were observed simultaneously and confirm our previous observations. This transition is followed by a second transition at 1.2 GPa to a new polymorph that is characterized for the first time. On increasing pressure, the diffraction pattern of phase III deteriorates significantly. On decompression phase III persists to 0.54 GPa before transformation to the ambient pressure phase. There is significant loss of signal after decompression, signifying that there has been a loss of material through polymerization. The orientation of the molecules in phase III provides insight into the possible polymerization reaction. PMID:26289930

  5. Preparation and characterization of methacrylate hydrogels for zeta potential control

    NASA Technical Reports Server (NTRS)

    Gregonis, D. E.; Ma, S. M.; Vanwagenen, R.; Andrade, J. D.

    1976-01-01

    A technique based on the measurement of streaming potentials has been developed to evaluate the effects of hydrophilic coatings on electroosmotic flow. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of glass capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming potential measurements is discussed. Various silane adhesion promoters exhibited only a slight decrease in streaming potential. A coating utilizing a glycidoxy silane base upon which methylcellulose is applied affords a six-fold decrease over uncoated tubes. Hydrophilic methacrylate gels show similar streaming potential behavior, independent of the water content of the gel. By introduction of positive or negative groups into the hydrophilic methacrylate gels, a range of streaming potential values are obtained having absolute positive or negative signs.

  6. Physical properties of agave cellulose graft polymethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-01

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm-1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  7. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi; Samuel S. Tam

    1999-04-21

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (January-March/99), in-situ formaldehyde generation and condensation with methyl propionate were tested over various catalysts and reaction conditions. The patent application is in preparation and the results are retained for future reports.

  8. SYNTHESIS OF METHACRYLATES FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Jang, B.W.L.; Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1999-12-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel have developed a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the US Department of Energy/Fossil Energy Technology Center (DOE/FETC). This project has resulted in five US patents (four already published and one pending publication). It has served as the basis for the technical and economic assessment of the production of this high-volume intermediate from coal-derived synthesis gas. The three-step process consists of the synthesis of a propionate from ethylene carbonylation using coal-derived CO, condensation of the propionate with formaldehyde to form methacrylic acid (MAA); and esterification of MAA with methanol to yield MMA. The first two steps, propionate synthesis and condensation catalysis, are the key technical challenges and the focus of the research presented here.

  9. Synthesis and characterization of magnetic poly(glycidyl methacrylate) microspheres

    NASA Astrophysics Data System (ADS)

    Horák, Daniel; Petrovský, Eduard; Kapička, Aleš; Frederichs, Theodor

    2007-04-01

    Magnetic nanoparticles encapsulated in poly(glycidyl methacrylate) microspheres were prepared and their detailed structural and magnetic characteristics given. Iron oxide nanoparticles were obtained by chemical coprecipitation of Fe(II) and Fe(III) salts and stabilized with dextran, (carboxymethyl)dextran or tetramethylammonium hydroxide. The microspheres were prepared by emulsion or dispersion polymerization of glycidyl methacrylate in the presence of ferrofluid. The microspheres were uniform both in shape and usually also in size; their size distribution was narrow. All the magnetic parameters confirm superparamagnetic nature of the microspheres. Blocking temperature was not observed, suggesting the absence of magnetic interactions at low temperatures. This is most probably caused by complete encapsulation and the absence of agglomeration. Such microspheres can be used in biomedical applications.

  10. Physical properties of agave cellulose graft polymethyl methacrylate

    SciTech Connect

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  11. Penile enlargement with methacrylate injection: is it safe?

    PubMed

    Torricelli, Fabio Cesar Miranda; Andrade, Enrico Martins de; Marchini, Giovanni Scala; Lopes, Roberto Iglesias; Claro, Joaquim Francisco Almeida; Cury, Jose; Srougi, Miguel

    2013-01-01

    CONTEXT Penis size is a great concern for men in many cultures. Despite the great variety of methods for penile augmentation, none has gained unanimous acceptance among experts in the field. However, in this era of minimally invasive procedure, injection therapy for penile augmentation has become more popular. Here we report a case of methacrylate injection in the penis that evolved with penile deformity and sexual dysfunction. This work also reviews the investigation and management of this pathological condition. CASE REPORT A 36-year-old male sought medical care with a complaint of penile deformity and sexual dysfunction after methacrylate injection. The treatment administered was surgical removal. Satisfactory cosmetic and functional results were reached after two months. CONCLUSIONS There is a need for better structured scientific research to evaluate the outcomes and complication rates from all penile augmentation procedures. PMID:23538596

  12. [Chest granuloma secondary to methyl methacrylate. Case report].

    PubMed

    Martínez-Bistrain, Ricardo; Robles García, Verónica; Cornejo-Morales, Ivonne

    2010-01-01

    We present the case of a patient with a history of a massive left hemithorax crushing injury in 1985; the exact management of the lesion is unknown. Twenty years later he had a thoracic fistula with a culture that was reported as positive for Enteroccocus faecalis and Staphyloccocus epidermidis. The patient was referred by the chest surgery service with the diagnosis of rib osteomyelitis once complementary imaging tests were performed (plain X-rays, CAT scan and MRI). The patient underwent surgery at our service; a granulomatous reaction secondary to a foreign body (methyl methacrylate and Ethibon) was reported. Chest reconstruction for massive lesions is possible with methyl methacrylate. Imaging studies involve the well-known difficulty to identify this material, given that it may produce signals and densities that are difficult to interpret by specialized physicians. PMID:20377062

  13. Biodegradation of polystyrene, poly(metnyl methacrylate), and phenol formaldehyde.

    PubMed Central

    Kaplan, D L; Hartenstein, R; Sutter, J

    1979-01-01

    The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellulose and mineral failed to increase decomposition rates significantly. PMID:533278

  14. PolyGuanine methacrylate cryogels for ribonucleic acid purification.

    PubMed

    Köse, Kazım; Uzun, Lokman

    2016-05-01

    The isolation and purification of ribonucleic acid have attracted attention recently for the understanding of the functions in detail because of the necessity for the treatment of genetic diseases. In this study, guanine-incorporated polymeric cryogels were developed to obtain highly purified ribonucleic acid. The satisfactory purification performance was achieved with the guanine-incorporated poly (2-hydroxyethyl methacrylate-guanine methacrylate) cryogels. The most crucial advantages to use guanine as a functional monomer are to obtain a real natural interaction between guanine on the polymeric material and cytosine on the ribonucleic acid. Moreover, using cryogel with a highly porous structure and high swelling ratio provide advantages of getting more water within the structure to get more analyte to interact. The characterization of cryogels has proved the success of the synthesis and the perfect natural interaction to be taken place between the ligand (guanine methacrylate) and the cytosine in the ribonucleic acid molecules. Although the pores within the structure of cryogels are small, they provide efficient and fast adsorption. The chromatographic separation performance was investigated for different conditions (pH, temperature etc.). The desorption ratio and reusability were also analyzed at the end of the five adsorption-desorption cycles with no significant changes. PMID:27004613

  15. Evaluation of alternate routes for the synthesis of methyl methacrylate

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1998-12-31

    The use of coal-derived syngas to produce high value chemicals is an important means of upgrading this resource. One example of a chemical that can be produced from coal-derived syngas is methyl methacrylate (MMA). Poly-methyl methacrylate is widely used in coatings and in various industrial molded products. The most widely practiced commercial technology for the synthesis of MMA is the acetone cyanohydrin (ACH) process. This process requires handling of large quantities of toxic hydrogen cyanide and generates one mole of ammonium bisulfate waste per mole of MMA. This bisulfate must either be regenerated or discarded, either of which substantially increases the cost. The ACH technology is thus environmentally and economically untenable for any new MMA plant expansions that would be needed to meet increasing demand. The RTI-Eastman-Bechtel research team is developing an alternative, environmentally benign route to MMA consisting of three steps; (step 1) synthesis of a propionate from ethylene, carbon monoxide, and steam, (step 2) condensation of this propionate with formaldehyde, and (step 3) esterification of resulting methacrylic acid with methanol to form MMA. This paper describes the preliminary economics of the overall process compared to other emerging processes, and focuses on step 2, including long term testing of catalysts for the condensation of propionic acid with formaldehyde to form MAA.

  16. Testing for ethanol markers in hair: discrepancies after simultaneous quantification of ethyl glucuronide and fatty acid ethyl esters.

    PubMed

    Kintz, P; Nicholson, D

    2014-10-01

    The hair of 97 cases were analysed for ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE, including ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) according to the Society of Hair Testing guidelines to examine the role of both tests in documenting chronic excessive alcohol drinking, particularly when the results are in contradiction. 27 (27.8%) results were EtG negative and FAEE positive, when applying the SoHT cut-offs, probably due to the use of alcohol-containing hair products. Four cases (4.1%) were EtG positive and FAEE negative that were attributed to the use of herbal lotions containing EtG. PMID:24794020

  17. Synthesis and serotonergic activity of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives: novel antagonists for the vascular 5-HT(1B)-like receptor.

    PubMed

    Moloney, G P; Martin, G R; Mathews, N; Milne, A; Hobbs, H; Dodsworth, S; Sang, P Y; Knight, C; Williams, M; Maxwell, M; Glen, R C

    1999-07-15

    The synthesis and vascular 5-HT(1B)-like receptor activity of a novel series of substituted 2, N-benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N, N-dimethyltryptamine derivatives are described. Modifications to the 5-ethylene-linked heterocycle and to substituents on the 2-benzylamide side chain have been explored. Several compounds were identified which exhibited affinity at the vascular 5-HT(1B)-like receptor of pK(B) > 7.0, up to 100-fold selectivity over alpha(1)-adrenoceptor affinity and 5-HT(2A) receptor affinity, and which exhibited a favorable pharmacokinetic profile. N-Benzyl-3-[2-(dimethylamino)ethyl]-5-[2-(4,4-dimethyl-2, 5-dioxo-1-imidazolidinyl)ethyl]-1H-indole-2-carboxamide (23) was identified as a highly potent, silent (as judged by the inability of angiotensin II to unmask 5-HT(1B)-like receptor-mediated agonist activity in the rabbit femoral artery), and competitive vascular 5-HT(1B)-like receptor antagonist with a plasma elimination half-life of approximately 4 h in dog plasma and with good oral bioavailability. The selectivity of compounds from this series for the vascular 5-HT(1B)-like receptors over other receptor subtypes is discussed as well as a proposed mode of binding to the receptor pharmacophore. It has been proposed that the aromatic ring of the 2, N-benzylcarboxamide group can occupy an aromatic binding site rather than the indole ring. The resulting conformation allows an amine-binding site to be occupied by the ethylamine nitrogen and a hydrogen-bonding site to be occupied by one of the hydantoin carbonyls. The electronic nature of the 2,N-benzylcarboxamide aromatic group as well as the size of substituents on this aromatic group is crucial for producing potent and selective antagonists. The structural requirement on the 3-ethylamine side chain incorporating the protonatable nitrogen is achieved by the bulky 2, N-benzylcarboxamide group and its close proximity to the 3-side chain. PMID:10411472

  18. Different in vitro and in vivo behaviors between Poly(carboxybetaine methacrylate) and poly(sulfobetaine methacrylate).

    PubMed

    Lin, Weifeng; Ma, Guanglong; Wu, Jiang; Chen, Shengfu

    2016-10-01

    Poly(sulfobetaine methacrylate) (pSBMA) and poly(carboxybetaine methacrylate) (pCBMA) are two well-known zwitterionic polymers known for their excellent antifouling properties. In this work, these two zwitterionic polymers were compared both in vitro and in vivo. Both of them exhibited excellent antifouling properties and low macrophage uptake although there were negligible differences in resistance to nonspecific protein adsorption of their hydrogels and cell internalization of their star polymers. However, it is found that the β- Cyclodextrin-CBMA (CD-CBMA) showed a circulation time one order of magnitude longer than CD-SBMA, which implied that small differences in vitro may lead to a dramatic difference in vivo. This work demonstrated that pCBMA showed greater potential than pSBMA in biomedical applications. PMID:27459415

  19. IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)

    EPA Science Inventory

    EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database.

  20. 46 CFR 151.50-42 - Ethyl ether.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Ethyl ether. 151.50-42 Section 151.50-42 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES BARGES CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-42 Ethyl ether. (a)(1) Gravity...

  1. Occupational allergic contact dermatitis from ethyl cyanoacrylate.

    PubMed

    Bruze, M; Björkner, B; Lepoittevin, J P

    1995-03-01

    Glues based on cyanoacrylates are widely used as contact adhesives for metal, glass, rubber, plastics and textiles, as well for biological materials, including binding tissues and sealing wounds in surgery. In this paper, an apprentice cobbler with an occupational allergic contact dermatitis from an ethyl cyanoacrylate glue, in which the major monomer was shown to be the sensitizer, is reported. Initial patch testing with the cyanoacrylate glue dissolved in acetone with the Finn Chamber (aluminium) technique yielded false-negative reactions. Positive test reactions were obtained with the same preparations using Van der Bend chambers. With petrolatum as vehicle for the glue, there was no difference between Finn Chamber technique and Van der Bend chamber technique. The role of aluminium in the false-negative reactions is discussed. PMID:7774187

  2. A morphogenetic regulatory role for ethyl alcohol in Candida albicans.

    PubMed

    Chauhan, Nitin M; Raut, Jayant S; Karuppayil, S Mohan

    2011-11-01

    Regulation of morphogenesis through the production of chemical signalling molecules such as isoamyl alcohol, 2-phenylethyl alcohol, 1-dodecanol, E-nerolidol and farnesol is reported in Candida albicans. The present study focuses on the effect of ethyl alcohol on C. albicans dimorphism and biofilm development. Ethyl alcohol inhibited germ tube formation induced by the four standard inducers in a concentration-dependent manner. The germ tube inhibitory concentration (4%) did not have any effect on the growth and viability of C. albicans cells. Ethyl alcohol also inhibited the elongation of germ tubes. Four percentage of ethyl alcohol significantly inhibited biofilm development on polystyrene and silicone surfaces. We suggest a potential morphogenetic regulatory role for ethyl alcohol, which may influence dissemination, virulence and establishment of infection. PMID:21605190

  3. Fragmentation dynamics of the ethyl bromide and ethyl iodide cations: a velocity-map imaging study.

    PubMed

    Gardiner, Sara H; Karsili, Tolga N V; Lipciuc, M Laura; Wilman, Edward; Ashfold, Michael N R; Vallance, Claire

    2014-02-01

    The photodissociation dynamics of ethyl bromide and ethyl iodide cations (C2H5Br(+) and C2H5I(+)) have been studied. Ethyl halide cations were formed through vacuum ultraviolet (VUV) photoionization of the respective neutral parent molecules at 118.2 nm, and were photolysed at a number of ultraviolet (UV) photolysis wavelengths, including 355 nm and wavelengths in the range from 236 to 266 nm. Time-of-flight mass spectra and velocity-map images have been acquired for all fragment ions and for ground (Br) and spin-orbit excited (Br*) bromine atom products, allowing multiple fragmentation pathways to be investigated. The experimental studies are complemented by spin-orbit resolved ab initio calculations of cuts through the potential energy surfaces (along the RC-Br/I stretch coordinate) for the ground and first few excited states of the respective cations. Analysis of the velocity-map images indicates that photoexcited C2H5Br(+) cations undergo prompt C-Br bond fission to form predominantly C2H5(+) + Br* products with a near-limiting 'parallel' recoil velocity distribution. The observed C2H3(+) + H2 + Br product channel is thought to arise via unimolecular decay of highly internally excited C2H5(+) products formed following radiationless transfer from the initial excited state populated by photon absorption. Broadly similar behaviour is observed in the case of C2H5I(+), along with an additional energetically accessible C-I bond fission channel to form C2H5 + I(+) products. HX (X = Br, I) elimination from the highly internally excited C2H5X(+) cation is deemed the most probable route to forming the C2H4(+) fragment ions observed from both cations. Finally, both ethyl halide cations also show evidence of a minor C-C bond fission process to form CH2X(+) + CH3 products. PMID:24317740

  4. Mechanistic insight into alkylation of the ethyl acetoacetate anion with different ethyl halides

    NASA Astrophysics Data System (ADS)

    Marković, S.; Đurđević, J.; Vukosavljević, M.; Petrović, Z.

    2013-12-01

    The alkylation reactions of the ambident ethyl acetoacetate anion with C2H5X (X = F, Cl, Br, and I) in the O2, C3, and O4 positions of the anion were investigated at the B3LYP/6-311+G( d,p) level of theory. It was found that the ethylation reaction does not occur in the position O4, as well as with ethyl fluoride in any position of the anion, due to very high activation energies and thermodynamic instability of the hypothetic products. The activation energies for the reactions in the position O2 are lower in comparison to the position C3, but the products of the reactions in the C3 position are more stable than those in the position O4, implying that the C/O products ratio is controlled by both thermodynamic and kinetic factors, leading to the O2-product with the chloride, and C3-product with the iodide as leaving group.

  5. A new approach to network heterogeneity: Polymerization Induced Phase Separation in photo-initiated, free-radical methacrylic systems.

    PubMed

    Szczepanski, Caroline R; Pfeifer, Carmem S; Stansbury, Jeffrey W

    2012-09-28

    Non-reactive, thermoplastic prepolymers (poly- methyl, ethyl and butyl methacrylate) were added to a model homopolymer matrix composed of triethylene glycol dimethacrylate (TEGDMA) to form heterogeneous networks via polymerization induced phase separation (PIPS). PIPS creates networks with distinct phase structure that can partially compensate for volumetric shrinkage during polymerization through localized internal volume expansion. This investigation utilizes purely photo-initiated, free-radical systems, broadening the scope of applications for PIPS since these processing conditions have not been studied previously.The introduction of prepolymer into TEGDMA monomer resulted in stable, homogeneous monomer formulations, most of which underwent PIPS upon photo-irradiation, creating heterogeneous networks. During polymerization the presence of prepolymer enhanced autoacceleration, allowing for a more extensive ambient cure of the material. Phase separation, as characterized by dynamic changes in sample turbidity, was monitored simultaneously with monomer conversion and either preceded or was coincident with network gelation. Dynamic mechanical analysis shows a broadening of the tan delta peak and secondary peak formation, characteristic of phase-separated materials, indicating one phase rich in prepolymer and another depleted form upon phase separation. In certain cases, PIPS leads to an enhanced physical reduction of volumetric shrinkage, which is attractive for many applications including dental composite materials. PMID:23109733

  6. Phosphatidylcholine covalently linked to a methacrylate-based monolith as a biomimetic stationary phase for capillary liquid chromatography.

    PubMed

    Moravcová, Dana; Carrasco-Correa, Enrique Javier; Planeta, Josef; Lämmerhofer, Michael; Wiedmer, Susanne K

    2015-07-10

    In this study a strategy to immobilize phospholipids onto a polymer-based stationary phase is described. Methacrylate-based monoliths in capillary format (150×0.1mm) were modified by soybean phosphatidylcholine through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide coupling to obtain stationary phases suitable to mimic cell surface membranes. The covalent coupling reaction involves the phosphate group in phospholipids; therefore, the described methodology is suitable for all types of phospholipids. Immobilization of soy bean phosphatidylcholine on the monolith was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry of the fatty alcohol profile, generated upon reductive cleavage of the fatty acyl side chains of the phospholipid on the monolith surface with lithium aluminium hydride. The prepared stationary phases were evaluated through studies on the retention of low-molar mass model analytes including neutral, acidic, and basic compounds. Liquid chromatographic studies confirmed predominant hydrophobic interactions between the analytes and the synthesized stationary phase; however, electrostatic interactions contributed to the retention as well. The synthesized columns showed high stability even with fully aqueous mobile phases such as Dulbecco's phosphate-buffered saline solution. PMID:26024990

  7. Glycol methacrylate in light microscopy: nucleic acid cytochemistry.

    PubMed

    Cole, M B; Ellinger, J

    1981-07-01

    Techniques utilizing Feulgen, azure B bromide, methyl green-pyronin, gallocyanin chromalum and cresyl violet stains have been modified and adapted for visualizing nucleic acids in 0.5-2.0 micrometer sections of tissues embedded in glycol methacrylate (GMA). Methods for evaluating the stain specificity for DNA and RNA using deoxyribonuclease and ribonuclease digestions, aldehyde blocking, and acid extractions are also described. The specificity of the stains in GMA embedded tissues is comparable to that reported for paraffin-embedded tissues. PMID:6167720

  8. Density of radiolytic gas bubbles in polymethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Makkonen, T.; Tiainen, O. J. A.; Valkiainen, M.; Winberg, M.

    The density of the radiolytic gas bubbles in irradiated polymethyl methacrylate was measured during subsequent heat treatment as a function of radiation dose. The samples were irradiated in the core of the Triga Mark II reactor in Otaniemi. After the irradiation periods the samples were heat treated at 393 K. The number of the bubbles could be explained by a thermal activation model. The bubbles are born in material inhomogeneities and the threshold dose for the bubble initiation was about 25 Mrad for the heat treatment at 393 K under the atmospheric pressure.

  9. Jumpwise deformation of polymethyl methacrylate in the microplasticity region

    NASA Astrophysics Data System (ADS)

    Shpeizman, V. V.; Yakushev, P. N.; Mukhina, Zh. V.; Kuznetsov, E. V.; Smolyanskii, A. S.

    2013-05-01

    The deformation rate with a step of 325 nm has been measured under uniaxial compression at the initial stage of creep and shape recovery of a polymethyl methacrylate (PMMA) sample after unloading. The effect of low γ-ray doses and magnetic fields on the deformation has been studied. It has been shown that a weak pre-exposure of the PMMA sample structure to radiation and magnetic fields can cause a slight hardening in the microplasticity region. The deformation jump sizes have been determined on micro- and nanoscales. The effect of irradiation and magnetic fields manifests itself as redistributed contributions of various jumps to the deformation.

  10. Hardness of irradiated poly(methyl methacrylate) at elevated temperatures

    SciTech Connect

    Lu, K.-P.; Lee, Sanboh; Cheng, Cheu Pyeng

    2001-08-15

    The decrease in hardness induced by gamma irradiation in poly(methyl methacrylate) (PMMA) has been investigated. The hardness is assumed to decrease linearly with the concentration of radiation-induced defects. Annealing at high temperatures induces defect annihilation as tracked by an increase in hardness. The annihilation follows first-order kinetics during isothermal annealing. The dependence of hardness on the reciprocal of the time constant satisfies the Arrhenius equation, and the corresponding activation energy of the kinetic process decreases with increasing dose. The hardness of postannealed PMMA decreases linearly with increasing dose. {copyright} 2001 American Institute of Physics.

  11. Automated ARGET ATRP Accelerates Catalyst Optimization for the Synthesis of Thiol-Functionalized Polymers

    PubMed Central

    Siegwart, Daniel J.; Leiendecker, Matthias; Langer, Robert; Anderson, Daniel G.

    2013-01-01

    Conventional synthesis of polymers by ATRP is relatively low throughput, involving iterative optimization of conditions in an inert atmosphere. Automated, high-throughput controlled radical polymerization was developed to accelerate catalyst optimization and production of disulfide-functionalized polymers without the need of an inert gas. Using ARGET ATRP, polymerization conditions were rapidly identified for eight different monomers, including the first ARGET ATRP of 2-(diethylamino)ethyl methacrylate and di(ethylene glycol) methyl ether methacrylate. In addition, butyl acrylate, oligo(ethylene glycol) methacrylate 300 and 475, 2-(dimethylamino)ethyl methacrylate, styrene, and methyl methacrylate were polymerized using bis(2-hydroxyethyl) disulfide bis(2-bromo-2-methylpropionate) as the initiator, tris(2-pyridylmethyl)amine as the ligand, and tin(II) 2-ethylhexanoate as the reducing agent. The catalyst and reducing agent concentration was optimized specifically for each monomer, and then a library of polymers was synthesized systematically using the optimized conditions. The disulfide-functionalized chains could be cleaved to two thiol-terminated chains upon exposure to dithiothreitol, which may have utility for the synthesis of polymer bioconjugates. Finally, we demonstrated that these new conditions translated perfectly to conventional batch polymerization. We believe the methods developed here may prove generally useful to accelerate the systematic optimization of a variety of chemical reactions and polymerizations. PMID:23599541

  12. The immobilization of enzymes onto poly(ethylene)—g.co—methacrylic acid, [poly(ethylene)—g.co—hydroxyethyl methacrylate]—g.co—methacrylic acid and [poly(ethylene)—g.co—methacrylic acid]—g.co—hydroxyethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Da Silva, M. Alves; Gil, M. H.; Guiomar, J.; Lapa, E.; Machado, E.; Moreira, M.; Guthrie, J. T.; Kotov, S.

    A series of graft copolymers has been prepared based on the poly(ethylene) backbone. These carry functional groups which are effective in coupling and provide a level of hydrophilicity which is thought to be consistent with generating a suitable micro-environment for enzyme immobilization and subsequent enhanced biocatalyst stability. Four enzymes have been immobilized. These are papain, trypsin, glucose oxidase and α-chymotrypsin. The parent copolymers were assembled via radiation-induced grafting. Secondary grafting was achieved in two ways. The first involved grafting methacrylic acid onto poly(ethylene)—g.co—hydroxyethyl methacrylate, while the second involved grafting hydroxyethyl methacrylate onto poly(ethylene)—g.co—methacrylic acid. The results suggest that a high degree of specificity arises in the systems examined with regard to the enzymes, the type of copolymers and the coupling procedures. Generally, relatively large amounts of enzyme become covalently attached to the copolymers, though the overall level of activity is low. In this work it has been observed that the most satisfactory results were obtained when the partly hydrolyzed poly(ethylene)—g.co—hydroxyethyl methacrylate was used in the immobilization of the biocatalysts.

  13. Dual-Functional Antifogging/Antimicrobial Polymer Coating.

    PubMed

    Zhao, Jie; Ma, Li; Millians, William; Wu, Tiehang; Ming, Weihua

    2016-04-01

    Dual-functional antifogging/antimicrobial polymer coatings were prepared by forming a semi-interpenetrating polymer network (SIPN) of partially quaternized poly(2-(dimethylamino)ethyl methacrylate-co-methyl methacrylate) and polymerized ethylene glycol dimethacrylate network. The excellent antifogging behavior of the smooth coating was mainly attributed to the hydrophilic/hydrophobic balance of the partially quaternized copolymer, while the covalently bonded, hydrophobic quaternary ammonium compound (5 mol % in the copolymer) rendered the coating strongly antimicrobial, as demonstrated by the total kill against both Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli. The antimicrobial action of the SIPN coating was based on contact killing, without leaching of bactericidal species, as revealed by a zone-of-inhibition test. This type of dual-functional coating may find unique applications where both antimicrobial and antifogging properties are desired. PMID:26977525

  14. pH- and Temperature-Responsive P(DMAEMA-GMA)-Alginate Semi-IPN Hydrogels Formed by Radical and Ring-Opening Polymerization for Aminophylline Release.

    PubMed

    Gao, Chunmei; Liu, Mingzhu; Chen, Jun; Chen, Chen

    2012-01-01

    A novel poly((2-dimethylamino) ethyl methacrylate-glycidyl methacrylate)-alginate (P(DMAEMA-GMA)alginate) semi-IPN hydrogel was synthesized via radical polymerization of the double bonds and ring-opening of the epoxy groups without using catalyst and cross-linker. (1)H-NMR, FT-IR and DSC data were consistent with the expected structures for the hydrogels. The interior morphology of the hydrogels was also investigated by SEM. The swelling ratio and compressive strength of the hydrogels were measured. The semi-IPN hydrogel had pH and temperature sensitivity, and pH-sensitive points of all hydrogels were found to be at pH 5.0. The release behavior of the model drug, aminophylline, was found to be dependent on the hydrogel composition and environment pH, which manifests that these materials have potential applications as intelligent drug carriers. PMID:21513583

  15. Enhancing Dispersion and Properties of SWNT-polymer Nanocomposites by Controlled Non-covalent Interactions

    NASA Astrophysics Data System (ADS)

    Linton, Dias

    2008-03-01

    The enhancement of the dispersion and properties of singlewalled carbon nanotubes in a polymer nanocomposite via non-covalent interaction is studied. 1% w/w SWNT are dispersed in random copolymers of methyl methacrylate and 2-(dimethylamino)ethyl methacrylate (DMAEMA), where the composition of the copolymer varies from 0% to 50% DMAEMA. The resulting nanocomposites indicate the existence of interactions between the carbon nanotube and polymer matrix by a shift of the D* peak position (˜2600-2700 cm-1) of the polymer nanocomposite. The copolymer with 30% DMAEMA shows the smallest shift, suggesting that the nanotubes are debundled, where it is expected that this non-covalent interaction originate from the tertiary amino group in DMAEMA by formation of an electron-donor interaction with the SWNT.

  16. Atom Transfer Radical Copolymerization of Gradient Copolymers of HEMA/DMAEMA with Arbitrary Composition Profiles

    NASA Astrophysics Data System (ADS)

    Gallow, Keith; Loo, Yueh-Lin

    2009-03-01

    Gradient copolymers represent a new class of statistical copolymers where a non-uniform composition profile is controllably introduced along the length of the polymer chain. Gradient copolymers have thermal and mechanical properties that are different from random or block copolymers having the same average composition. Due to synthetic limitations, however, the introduction of arbitrary composition profiles remains challenging. Here, we demonstrate the ability to controllably introduce arbitrary composition profiles along copolymers of 2-hydroxyethyl methacrylate (HEMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) by atom transfer radical copolymerization in a semi-batch reactor. Using gas chromatography to monitor monomer consumption, we have constructed a kinetic model which we use as a basis to synthesize copolymers with linear and parabolic composition profiles. The overall DMAEMA content and molecular weight of these gradient copolymers were determined using nuclear magnetic resonance spectroscopy and size exclusion chromatography, respectively, and both show good agreement with our model's predictions.

  17. TECHNICAL NOTE: Application of hydrogel-coated microcantilevers as sensing elements for pH

    NASA Astrophysics Data System (ADS)

    Gonska, Julian; Schelling, Christoph; Urban, Gerald

    2009-12-01

    This note reports on cantilever-based sensor elements coated with a hydrogel. The hydrogel responds with a volume change on varying the pH value of surrounding liquids. The change in volume leads to a static deflection of the cantilevers, which is detected using integrated piezoresistors. To increase deflection sensitivity of the sensor elements, sub-micron, multilayered cantilevers consisting of polycrystalline silicon and silicon oxide are used. A new cantilever design is developed, which decreases the cantilever sensitivity to in situ stresses and thermal bimorph effects. A theoretical model for the sensor elements is introduced providing the output signal of multiple cantilevers connected in a full Wheatstone bridge. Measurements of deflection sensitivity prove the theoretical model. Finally, the cantilevers are coated with a 2-hydroxyethyl methacrylate and 2-(dimethylamino) ethyl methacrylate copolymer-based hydrogel, and changes in the pH value from pH 4 to pH 10 are measured.

  18. Amphiphilic star block copolymers as gene carrier part I: synthesis via ATRP using calix[4]resorcinarene-based initiators and characterization.

    PubMed

    Zheng, Anna; Xue, Yan; Wei, Dafu; Guan, Yong; Xiao, Huining

    2013-01-01

    In this work, a cationic star polymer [poly(2-dimethylamino)ethyl methacrylate (PDMAEMA)] was prepared via atom transfer radical polymerization (ATRP), using brominated calix[4]resorcinarene as an initiator. Hydrophobic moieties, methyl methacrylate (MMA) and butyl acrylate (BA), were further incorporated via "one-pot" method. Well-defined eight-armed star block copolymers bearing hydrophilic blocks inside and hydrophobic blocks outside were synthesized. The molecular weight, particle size, electrophoretic mobility and apparent charge density were determined by gel permeation chromatography (GPC), dynamic light scattering (DLS), phase analysis light scattering (PALS) and colloidal titration, respectively. The zeta potentials and apparent charge densities of the products exhibited the characteristics of polyelectrolyte. The incorporation of hydrophobic moieties generated electrostatic screening effect. The as-synthesized amphiphilic star copolymer is promising as a thermo-sensitive gene carrier for gene therapy. PMID:25428104

  19. Perspectives for the biotechnological production of ethyl acetate by yeasts.

    PubMed

    Löser, Christian; Urit, Thanet; Bley, Thomas

    2014-06-01

    Ethyl acetate is an environmentally friendly solvent with many industrial applications. The production of ethyl acetate currently proceeds by energy-intensive petrochemical processes which are based on natural gas and crude oil without exception. Microbial synthesis of ethyl acetate could become an interesting alternative. The formation of esters as aroma compounds in food has been repeatedly reviewed, but a survey which deals with microbial synthesis of ethyl acetate as a bulk product is missing. The ability of yeasts for producing larger amounts of this ester is known for a long time. In the past, this potential was mainly of scientific interest, but in the future, it could be applied to large-scale ester production from renewable raw materials. Pichia anomala, Candida utilis, and Kluyveromyces marxianus are yeasts which convert sugar into ethyl acetate with a high yield where the latter is the most promising one. Special attention was paid to the mechanism of ester synthesis including regulatory aspects and to the maximum and expectable yield. Synthesis of much ethyl acetate requires oxygen which is usually supplied by aeration. Ethyl acetate is highly volatile so that aeration results in its phase transfer and stripping. This stripping process cannot be avoided but requires adequate handling during experimentation and offers a chance for a cost-efficient process-integrated recovery of the synthesized ester. PMID:24788328

  20. Ethyl pyruvate protects colonic anastomosis from ischemia-reperfusion injury.

    PubMed

    Unal, B; Karabeyoglu, M; Huner, T; Canbay, E; Eroglu, A; Yildirim, O; Dolapci, M; Bilgihan, A; Cengiz, O

    2009-03-01

    Ethyl pyruvate is a simple derivative in Ca(+2)- and K(+)-containing balanced salt solution of pyruvate to avoid the problems associated with the instability of pyruvate in solution. It has been shown to ameliorate the effects of ischemia-reperfusion (I/R) injury in many organs. It has also been shown that I/R injury delays the healing of colonic anastomosis. In this study, the effect of ethyl pyruvate on the healing of colon anastomosis and anastomotic strength after I/R injury was investigated. Anastomosis of the colon was performed in 32 adult male Wistar albino rats divided into 4 groups of 8 individuals: (1) sham-operated control group (group 1); (2) 30 minutes of intestinal I/R by superior mesenteric artery occlusion (group 2); (3) I/R+ ethyl pyruvate (group 3), ethyl pyruvate was administered as a 50-mg/kg/d single dose; and (4) I/R+ ethyl pyruvate (group 4), ethyl pyruvate administration was repeatedly (every 6 hours) at the same dose (50 mg/kg). On the fifth postoperative day, animals were killed. Perianastomotic tissue hydroxyproline contents and anastomotic bursting pressures were measured in all groups. When the anastomotic bursting pressures and tissue hydroxyproline contents were compared, it was found that they were decreased in group 2 when compared with groups 1, 3, and 4 (P < .05). Both anastomotic bursting pressure (P = .005) and hydroxyproline content (P < .001) levels were found to be significantly increased with ethyl pyruvate administration when compared with group 2. When ethyl pyruvate administration doses were compared, a significant difference was not observed (P > .05). Ethyl pyruvate significantly prevents the delaying effect of I/R injury on anastomotic strength and healing independent from doses of administration. PMID:19064591

  1. Preparation of Novel Poly(hydroxyethyl methacrylate-coglycidyl methacrylate)-Grafted Core-Shell Magnetic Chitosan Microspheres and Immobilization of Lactase

    PubMed Central

    Zhao, Wei; Yang, Rui-Jin; Qian, Ting-Ting; Hua, Xiao; Zhang, Wen-Bin; Katiyo, Wendy

    2013-01-01

    Poly(hydroxyethyl methacrylate-co-glycidyl methacrylate)-grafted magnetic chitosan microspheres (HG-MCM) were prepared using reversed-phase suspension polymerization method. The HG-MCM presented a core-shell structure and regular spherical shape with poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) grafted onto the chitosan layer coating the Fe3O4 cores. The average diameter of the magnetic microspheres was 10.67 μm, within a narrow size distribution of 6.6–17.4 μm. The saturation magnetization and retentivity of the magnetic microspheres were 7.0033 emu/g and 0.6273 emu/g, respectively. The application of HG-MCM in immobilization of lactase showed that the immobilized enzyme presented higher storage, pH and thermal stability compared to the free enzyme. This indicates that HG-MCM have potential applications in bio-macromolecule immobilization. PMID:23743822

  2. Backfilling-Free Strategy for Biopatterning on Intrinsically Dual-Functionalized Poly[2-Aminoethyl Methacrylate-co-Oligo(Ethylene Glycol) Methacrylate] Films.

    PubMed

    Lee, Bong Soo; Lee, Juno; Han, Gyeongyeop; Ha, EunRae; Choi, Insung S; Lee, Jungkyu K

    2016-07-20

    We demonstrated protein and cellular patterning with a soft lithography technique using poly[2-aminoethyl methacrylate-co-oligo(ethylene glycol) methacrylate] films on gold surfaces without employing a backfilling process. The backfilling process plays an important role in successfully generating biopatterns; however, it has potential disadvantages in several interesting research and technical applications. To overcome the issue, a copolymer system having highly reactive functional groups and bioinert properties was introduced through a surface-initiated controlled radical polymerization with 2-aminoethyl methacrylate hydrochloride (AMA) and oligo(ethylene glycol) methacrylate (OEGMA). The prepared poly(AMA-co-OEGMA) film was fully characterized, and among the films having different thicknesses, the 35 nm-thick biotinylated, poly(AMA-co-OEGMA) film exhibited an optimum performance, such as the lowest nonspecific adsorption and the highest specific binding capability toward proteins. PMID:27252120

  3. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  4. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  5. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  6. Cell toxicity of methacrylate monomers-the role of glutathione adduct formation.

    PubMed

    Ansteinsson, V; Kopperud, H B; Morisbak, E; Samuelsen, J T

    2013-12-01

    Polymer-based dental restorative materials are designed to polymerize in situ. However, the conversion of methacrylate monomer to polymer is never complete, and leakage of the monomer occurs. It has been shown that these monomers are toxic in vitro; hence concerns regarding exposure of patients and dental personnel have been raised. Different monomer methacrylates are thought to cause toxicity through similar mechanisms, and the sequestration of cellular glutathione (GSH) may be a key event. In this study we examined the commonly used monomer methacrylates, 2-hydroxyethylmethacrylate (HEMA), triethylenglycol-dimethacrylate (TEGDMA), bisphenol-A-glycidyl-dimethacrylate (BisGMA), glycerol-dimethacrylate (GDMA) and methyl-methacrylate (MMA). The study aimed to establish monomers' ability to complex with GSH, and relate this to cellular toxicity endpoints. Except for BisGMA, all the monomer methacrylates decreased the GSH levels both in cells and in a cell-free system. The spontaneous formation of methacrylate-GSH adducts were observed for all methacrylate monomers except BisGMA. However, we were not able to correlate GSH depletion and toxic response measured as SDH activity and changes in cell growth pattern. Together, the current study indicates mechanisms other than GSH-binding to be involved in the toxicity of methacrylate monomers. PMID:23613115

  7. ACUTE TOXICITY AND BEHAVIORAL EFFECTS OF ACRYLATES AND METHACRYLATES TO JUVENILE FATHEAD MINNOWS (JOURNAL VERSION)

    EPA Science Inventory

    Acrylate and methacrylate esters are reactive monomers that are used primarily in the synthesis of acrylic plastics and polymers. Ninety-six hour flow-through acute toxicity tests were conducted with fathead minnows (Pimephales promelas) using 6 acrylates and 6 methacrylates. Nin...

  8. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... reporting. (1) The chemical substance identified generically as hydroxypropyl methacrylate, reaction... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Hydroxypropyl methacrylate, reaction... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  9. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting. (1) The chemical substance identified generically as hydroxypropyl methacrylate, reaction... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Hydroxypropyl methacrylate, reaction... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  10. 40 CFR 721.10375 - Hydroxypropyl methacrylate, reaction products with propylene oxide and ethylene oxide, copolymer...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting. (1) The chemical substance identified generically as hydroxypropyl methacrylate, reaction... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Hydroxypropyl methacrylate, reaction... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  11. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  12. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2010 CFR

    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...

  13. 21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl...

  14. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 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...

  15. Adsorption of water vapor on modified methacrylate polymeric sorbents

    SciTech Connect

    Platonova, N.P.; Tataurova, O.G.; Vartapetyan, R.Sh.

    1995-12-31

    Adsorption of water vapor on methacrylate copolymers and terpolymers was studied. An increase in the content of the cross-linking agent gives rise to increase in the limiting adsorption of water vapor at the saturation pressure (a{sub s}) and to decrease in the concentration of primary adsorption centers. Modification of the initial copolymer containing 60% of 2,3-epoxypropyl methacrylate (EPMA) monomer and 40% of cross-linking agent, ethylene dimethacrylate, with diethylenetriamine (DETA) results in an increase in the a{sub s} value, while modification with C{sub 12} and C{sub 18} alkyl, benzyl, and phenyl groups gives rise to decrease in the a{sub s} values for the copolymeric sorbents. The concentration of primary adsorption centers (a{sub m}) increases considerably on modification of the copolymer with DETA and C{sub 12} groups and decreases markedly on modification with benzyl and phenyl groups. For terpolymers, containing EPMA and styrene, an increase in the styrene/EPMA ratio reduces the a{sub s}, and a{sub m} values. The copolymer modified with DETA groups possesses the most hydrophilic properties, while the copolymer modified with benzyl group exhibits the most hydrophobic properties. The mechanism of adsorption of water molecules on the polymers is discussed.

  16. Superhydrophobic terpolymer nanofibers containing perfluoroethyl alkyl methacrylate by electrospinning

    NASA Astrophysics Data System (ADS)

    Cengiz, Ugur; Avci, Merih Z.; Erbil, H. Yildirim; Sarac, A. Sezai

    2012-05-01

    A new statistical terpolymer containing perfluoroethyl alkyl methacrylate (Zonyl-TM), methyl methacrylate and butyl acrylate, poly(Zonyl-TM-ran-MMA-ran-BA) was synthesized in supercritical carbon dioxide at 200 bar and 80 °C using AIBN as an initiator by heterogeneous free radical copolymerization. Nanofibers of this terpolymer were produced by electrospinning from its DMF solution. The structural and thermal properties of terpolymers and electrospun poly(Zonyl-TM-MMA-BA) nanofibers were analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and differential scanning calorimetry. Nanofiber morphology was investigated by scanning electron microscopy. Electrospun nanofiber layer was found to be superhydrophobic with a water contact angle of 172 ± 1° and highly oleophobic with hexadecane, glycerol and ethylene glycol contact angles of 70 ± 1°, 167 ± 1° and 163 ± 1° respectively. The change of the contact angle results on the electrospun fiber layer and flat terpolymer surfaces by varying feed monomer composition were compared and discussed in the text.

  17. Novel syngas-based process for methyl methacrylate

    SciTech Connect

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.; Choi, G.N.; Tam, S.S.; Tischer, R.E.; Srivastava, R.D.

    1996-12-31

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel are developing a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy, Pittsburgh Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the research on propionate synthesis step. The resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees}C and 180 atm). Bechtel has performed an extensive cost analysis, which shows that Eastman`s propionate synthesis process is competitive with other technologies to produce the anhydride. In the second step, RTI and Eastman have developed active and stable V-SI-P and Ta metal oxide catalysts for condensation reactions of propionates with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst activity. Current research focuses on enhancing the condensation reaction yields, acid-base properties, in situ condensation in a high- temperature, high-pressure (HTHP) slurry reactor, and alternate formaldehyde feedstocks. Based on Eastman and RTI laboratory reactor operating data, a cost estimate is also being developed for the integrated process.

  18. Synthesis of Methyl Methacrylate from Coal-Derived Syngas

    SciTech Connect

    Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Makarand R. Gogate; Richard D. Colberg; Samuel S. Tam

    1998-04-17

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last month, RTI has finalized the design of a fixed-bed microreactor system for DME partial oxidation reactions. RTI incorporated some design changes to the feed blending system, so as to be able to blend varying proportions of DME and oxygen. RTI has also examined the flammability limits of DME-air mixtures. Since the lower flammability limit of DME in air is 3.6 volume percent, RTI will use a nominal feed composition of 1.6 percent in air, which is less than half the lower explosion limit for DME-air mixtures. This nominal feed composition is thus considered operationally safe, for DME partial oxidation reactions. RTI is also currently developing an analytical system for DME partial oxidation reaction system.

  19. On the cause of low thermal stability of ethyl halodiazoacetates

    PubMed Central

    Mortén, Magnus; Hennum, Martin

    2016-01-01

    Summary Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  20. On the cause of low thermal stability of ethyl halodiazoacetates.

    PubMed

    Mortén, Magnus; Hennum, Martin; Bonge-Hansen, Tore

    2016-01-01

    Rates for the thermal decomposition of ethyl halodiazoacetates (halo = Cl, Br, I) have been obtained, and reported herein are their half-lives. The experimental results are supported by DFT calculations, and we provide a possible explanation for the reduced thermal stability of ethyl halodiazoacetates compared to ethyl diazoacetate and for the relative decomposition rates between the chloro, bromo and iodo analogs. We have also briefly studied the thermal, non-catalytic cyclopropanation of styrenes and compared the results to the analogous Rh(II)-catalyzed reactions. PMID:27559411

  1. Investigation of infrared calibration methods for application to the study of methyl methacrylate polymerization.

    PubMed

    Kaczmarczyk, B; Morejko-Buz, B; Stolarzewicz, A

    2001-08-01

    Infrared spectroscopy has been used to monitor the polymerization of methyl methacrylate. Concentrations of methyl methacrylate in the reaction mixture were determined by use of three calibration methods. Classical quantitative analysis was used to measure the height of the stretching vibration bands of the vinyl group at 1639 cm(-1). A calibration procedure using the considerably higher intensity of the C = O stretching vibration band of the carbonyl ester group at 1725 cm(-1) seemed useful only for high concentrations of methyl methacrylate, i.e. at the beginning of reaction, because this band overlaps that of poly(methyl methacrylate). Use of second-derivative spectra and measuring their values at 1725 cm(-1) enabled estimation of ten times lower concentrations of methyl methacrylate the calibration using the band from the vinyl group. PMID:11569872

  2. Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow.

    PubMed

    Müller, Simon T R; Hokamp, Tobias; Ehrmann, Svenja; Hellier, Paul; Wirth, Thomas

    2016-08-16

    Ethyl diazoacetate (EDA) is one of the most prominent diazo reagents. It is frequently used in metal-carbene-type reactions. However, EDA can also be used as a nucleophile under base catalysis. Whilst the addition of EDA to aldehydes can be performed using organic bases, the addition of EDA to other carbonyl electrophiles requires the use of organometallics such as lithium diisopropylamide (LDA). The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at low temperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields. PMID:27339757

  3. [Reaction of 1,8-naphthyridine azides with ethyl acrylate].

    PubMed

    Livi, O; Ferrarini, P L; Bertini, D; Tonetti, I

    1975-12-01

    The reaction of 1,8-naphthyridine azides with ethyl acrylate leads to the formation of 2-pyrazolines instead of 1,2,3-triazolines. Some of the compounds obtained have undergone pharmacological and microbiological (antibacterial) testing. PMID:1204828

  4. Effects of quaternary ammonium-methacrylates on the mechanical properties of unfilled resins

    PubMed Central

    Hoshika, Tomohiro; Nishitani, Yoshihiro; Yoshiyama, Masahiro; Key, William O.; William, Brantley; Agee, Kelli A.; Breschi, Lorenzo; Cadenaro, Milena; Tay, Franklin R.; Rueggeberg, Frederick; Pashley, David H.

    2014-01-01

    Objectives Adding antimicrobial/anti-MMP quaternary ammonium methacrylates (QAMs) to comonomer blends should not weaken the mechanical properties of dental resins. This work evaluated the degree conversion and mechanical properties of BisGMA/TEGDMA/HEMA (60:30:10) containing 0–15 mass% QAMs A–E (A:2-acryloxyethyltrimethyl ammonium chloride; B:[3-(methacryloylamino)propyl]trimethylammonium chloride; C:[2-(methacryloxy)ethyl] trimethyl ammonium chloride; D:diallyldimethyl ammonium chloride; E:2-(methacryloyloxy) ethyltrimethyl ammonium methyl sulfate. Methods Unfilled resins with and without QAM were placed on ATR-FTIR and light-polymerized for 20 s in a thin film t 30°C. Unfilled resin beams were casted from square hollow glass tubings. Half of the beams were tested after 3 days of drying (control); the other half were tested wet after 3 days of water storage. Results Addition of QAMs in control resins significantly increased conversion 600s after light termination, with the exception of 5% MAPTAC (p<0.05). Increase of QAM content within a formulation significantly increased conversion. Control beams gave dry Young’s moduli of ~700 MPa. Addition of 5, 10 or 15 mass% QAMs produced significant reductions in dry Young’s moduli except for 5% B or C. 15 mass% A, B and C lowered the wet Young’s moduli of the resin beams by more than 30%. The ultimate tensile stress (UTS) of control dry resin was 89±11 MPa. Addition of 5–10 mass% QAMs had no adverse effect on the dry UTS. After water storage, the UTS of all resin blends fell significantly (p<0.05), especially when 15 wt% QAMs was added. Control dry beams gave fracture toughness (KIC) values of 0.88±0.1 MPa√m. Wet values were significantly higher at 1.02±0.06 (p<0.05). KIC of dry beams varied from 0.85±0.08 at 5% QAMs to 0.49±0.05 at 15% QAMs. Wet beams gave KIC values of 1.02±0.06 MPa√m that fell to 0.23±0.01 at 15% QAMs. Significance Addition of 10% QAMs increased the degree of conversion of

  5. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG

    1999-01-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(Oct.-Dec./98), we have investigated the condensation between methyl propionate and formaldehyde (MP/HCHO=4.5/1) at various reaction temperatures(280-360EC) over 5%, 10%, and 20% Nb O /SiO catalysts. The conversion of HCHO increases with reaction 2 5 2 temperature and niobium loading. MMA+MAA selectivity goes through a maximum with the temperature over both 10% and 20% Nb O /SiO . The selectivities to MMA+MAA are 67.2%, 2 5 2 72.3%and 58.1% at 320EC over 5%, 10%, 20% Nb O /SiO , respectively. However, the 2 5 2 conversion of formaldehyde decreases rapidly with time on stream. The results suggest that silica supported niobium catalysts are active and selective for condensation of MP with HCHO, but deactivation needs to be minimized for the consideration of commercial application. We have preliminarily investigated the partial oxidation of dimethyl ether(DME) over 5% Nb O /SiO catalyst. Reactant gas mixture of 0.1% DME, 0.1% O and balance nitrogen is 2 5 2 2 studied with temperature ranging from 200°C to 500°C. The conversion of DME first increases with temperature reaching an maximum at 400°C then decreases. The selectivity to HCHO also increases with reaction temperature first. But the selectivity to HCHO decreases at temperature above 350

  6. Ethyl cellulose amphiphilic graft copolymers with LCST-UCST transition: Opposite self-assembly behavior, hydrophilic-hydrophobic surface and tunable crystalline morphologies.

    PubMed

    Yuan, Hua; Chi, Hai; Yuan, Weizhong

    2016-08-20

    Novel and well-defined graft copolymer with block copolymer side chain, ethyl cellulose-graft-(poly(ε-caprolactone)-block-poly(N,N-dimethylaminoethylmeth acrylate)) (EC-g-(PCL-b-PDMAEMA)) with a lower critical solution temperature (LCST) was successfully synthesized via the combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). EC-g-(PCL-b-PDMAEMA) copolymers with various PCL-b-PDMAEMA block lengths were obtained by adjusting the molar ratios of the N,N-dimethylaminoethyl methacrylate monomer to ε-caprolactone. The EC-g-(PCL-b-PDMAPS) with an upper critical solution temperature (UCST) was obtained via facile quaternization reaction of PDMAEMA with 1,3-propane sultone. EC-g-(PCL-b-PDMAEMA) and EC-g-(PCL-b-PDMAPS) micelle solutions showed opposite thermoresponsiviness and hydrophilic-hydrophobic surface. Moreover, the tunable crystalline morphologies could be obtained from these graft copolymers through changing the polymer structure and PDMAEMA contents. PMID:27178932

  7. Radiation synthesis of nanosilver nanohydrogels of poly(methacrylic acid)

    NASA Astrophysics Data System (ADS)

    Gupta, Bhuvanesh; Gautam, Deepti; Anjum, Sadiya; Saxena, Shalini; Kapil, Arti

    2013-11-01

    Nanosilver nanohydrogels (nSnH) of poly(methacrylic acid) were synthesized and stabilized using gamma irradiation. The main objective of this study was to develop silver nanoparticles and to evaluate the antimicrobial activity. Radiation helps in the polymerization, crosslinking and reduction of silver nitrate as well. Highly stable and uniformly distributed silver nanoparticles have been obtained within hydrogel network by water in oil nanoemulsion polymerization and were evaluated by dynamic light scattering (DLS) and transmission electron microscopy (TEM) respectively. TEM showed almost spherical and uniform distribution of silver nanoparticles through the hydrogel network. The mean size of silver nanoparticles ranging is 10-50 nm. The nanohydrogels showed good swelling in water. Antibacterial studies of nSnH suggest that it can be a good candidate as coating material in biomedical applications.

  8. Thiol-ene/methacrylate systems for mechanical damping

    NASA Astrophysics Data System (ADS)

    McNair, Olivia; Senyurt, Askim; Wei, Huanyu; Gould, Trent; Piland, Scott; Hoyle, Charles; Savin, Daniel

    2010-03-01

    Ternary thiol-ene-methacrylate (TEMA) networks as materials for mechanical energy damping are unique to the sports world. Using a photoinitiation process, TEMA systems are formed via an initial thiol-ene step-growth mechanism along with traditional radical polymerization of acrylate and ene monomers. Final networks have two-part morphologies: acrylate homopolymer sectors imbedded in a multi-component mesh. Several (TEMA) systems have been synthesized and analyzed via thermal and mechanical probing. Initial studies on these ternary systems have shown excellent properties compared to traditional ethylene vinyl alcohol (EVA) copolymers. For example, PEMA networks exhibit glass transition temperatures 33 K higher than EVA, resulting in improved damping at room temperature. This research will help develop relationships between tan delta, glass transition and their effects on mechanical energy damping for ternary (TEMA) systems.

  9. Interaction between N-vinylpyrrolidone and methyl methacrylate

    NASA Astrophysics Data System (ADS)

    Zaitseva, V. V.; Shtonda, A. V.; Tyurina, T. G.; Bagdasarova, A. R.; Zaitsev, S. Yu.

    2014-04-01

    It is established that the interaction of the isomers of N-vinylpyrrolidone (NVP) and methyl methacrylate (MMA) leads to the formation of molecular π-H- and H-complexes with energies within the limits of 10.2-13.6 (AM1) or 18.2-24.0 (B3LYP/6-311++G( d)) kJ/mol. The structures of complex-bound molecules are examined with respect to changes in the charges on terminal -C1=C2- groups, the distance between them and atoms in an H-bond, and the presence of combined overlapping molecular orbitals (MOs). The presence of an averaged complex that includes presumably all possible structures and allows us to perform the copolymerization of specified monomers in the absence of an initiator is confirmed by means of UV and NMR spectroscopy.

  10. Atom Transfer Radical Polymerization of Methacrylic Acid: A Won Challenge.

    PubMed

    Fantin, Marco; Isse, Abdirisak A; Venzo, Alfonso; Gennaro, Armando; Matyjaszewski, Krzysztof

    2016-06-15

    Polymerization of acidic monomers is one of the biggest challenges for atom transfer radical polymerization (ATRP). An intramolecular cyclization reaction leading to the loss of the C-X chain-end functionality was found to be the main reason for the partial termination of the growing polymer chains. Three approaches were used to overcome this problem: using Cl as the chain-end halogen, lowering the pH (to 0.9), and increasing polymerization rate. Methacrylic acid (MAA) was polymerized by both electrochemically mediated ATRP and supplemental activator and reducing agent ATRP up to high conversion (>90%), in t ≤ 4 h at 25 °C, using inexpensive and nontoxic reagents (NaCl, diluted HCl, water). Control over molecular weight (MW) dispersity was satisfactory, and MWs were in agreement with theoretical values. The "livingness" of the process was confirmed by an electrochemical switch, used to repeatedly and periodically deactivate/reactivate growing chains. PMID:27244091

  11. Chest wall reconstruction with methacrylate prosthesis in Poland syndrome.

    PubMed

    Arango Tomás, Elisabet; Baamonde Laborda, Carlos; Algar Algar, Javier; Salvatierra Velázquez, Angel

    2013-10-01

    Poland syndrome is a rare congenital malformation. This syndrome was described in 1841 by Alfred Poland at Guy's Hospital in London. It is characterized by hypoplasia of the breast and nipple, subcutaneous tissue shortages, lack of the costosternal portion of the pectoralis major muscle and associated alterations of the fingers on the same side. Corrective treatment of the chest and soft tissue abnormalities in Poland syndrome varies according to different authors. We report the case of a 17-year-old adolescent who underwent chest wall reconstruction with a methyl methacrylate prosthesis. This surgical procedure is recommended for large anterior chest wall defects, and it prevents paradoxical movement. Moreover it provides for individual remodeling of the defect depending on the shape of the patient's chest. PMID:23453291

  12. Management of complication after breast augmentation with methacrylate

    PubMed Central

    Grella, Roberto; Almadori, Aurora; D’Ari, Antonio; Romanucci, Vincenza; D’Andrea, Francesco

    2015-01-01

    Introduction Several alloplastic biomaterials are available for injection to the breast, nevertheless not all of them are approved for biomedical use. Although in North America and Western Europe experience with synthetic biomaterials for breast augmentation is very limited, migratory streams might expose physicians worldwide to manage the related complications of these procedures. The aim of this study was to share with other surgeons the case of a patient presenting complications after breast augmentation with an unknown synthetic substance containing methacrylate. Presentation of case A 33-years old Asian woman presented to our Institution with breast deformities, lumps and chest pain. The patient referred previous breast injection “with hospital fat” performed in China six years before. She was not aware about the details of the procedure, and language barriers limited communication. Clinical examination and ultrasounds revealed the irregular distribution of an unknown substance in both breasts. The material was surgically removed and replaced in the same session with polyurethane implants. Chemical analysis revealed the presence of methacrylate. Discussion With a growing demand for non-invasive cosmetic surgery, has been reported a growing population of untrained and unlicensed personnel performing cosmetic surgery in many countries where there are no laws that restrict the use of cosmetic procedures to physicians with appropriate training and with approved materials. Surgical removal of this substances can be extremely challenging and an open procedure with surgical debridement is recommended. Conclusion Breast augmentation with non-absorbable biomaterials can lead to severe complications, in particular for patients intending to breastfeed. PMID:26298244

  13. Functional Human Vascular Network Generated in Photocrosslinkable Gelatin Methacrylate Hydrogels.

    PubMed

    Chen, Ying-Chieh; Lin, Ruei-Zeng; Qi, Hao; Yang, Yunzhi; Bae, Hojae; Melero-Martin, Juan M; Khademhosseini, Ali

    2012-05-23

    The generation of functional, 3D vascular networks is a fundamental prerequisite for the development of many future tissue engineering-based therapies. Current approaches in vascular network bioengineering are largely carried out using natural hydrogels as embedding scaffolds. However, most natural hydrogels present a poor mechanical stability and a suboptimal durability, which are critical limitations that hamper their widespread applicability. The search for improved hydrogels has become a priority in tissue engineering research. Here, the suitability of a photopolymerizable gelatin methacrylate (GelMA) hydrogel to support human progenitor cell-based formation of vascular networks is demonstrated. Using GelMA as the embedding scaffold, it is shown that 3D constructs containing human blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSCs) generate extensive capillary-like networks in vitro. These vascular structures contain distinct lumens that are formed by the fusion of ECFC intracellular vacuoles in a process of vascular morphogenesis. The process of vascular network formation is dependent on the presence of MSCs, which differentiate into perivascular cells occupying abluminal positions within the network. Importantly, it is shown that implantation of cell-laden GelMA hydrogels into immunodeficient mice results in a rapid formation of functional anastomoses between the bioengineered human vascular network and the mouse vasculature. Furthermore, it is shown that the degree of methacrylation of the GelMA can be used to modulate the cellular behavior and the extent of vascular network formation both in vitro and in vivo. These data suggest that GelMA hydrogels can be used for biomedical applications that require the formation of microvascular networks, including the development of complex engineered tissues. PMID:22907987

  14. Functional Human Vascular Network Generated in Photocrosslinkable Gelatin Methacrylate Hydrogels

    PubMed Central

    Chen, Ying-Chieh; Lin, Ruei-Zeng; Qi, Hao; Yang, Yunzhi; Bae, Hojae

    2012-01-01

    The generation of functional, 3D vascular networks is a fundamental prerequisite for the development of many future tissue engineering-based therapies. Current approaches in vascular network bioengineering are largely carried out using natural hydrogels as embedding scaffolds. However, most natural hydrogels present a poor mechanical stability and a suboptimal durability, which are critical limitations that hamper their widespread applicability. The search for improved hydrogels has become a priority in tissue engineering research. Here, the suitability of a photopolymerizable gelatin methacrylate (GelMA) hydrogel to support human progenitor cell-based formation of vascular networks is demonstrated. Using GelMA as the embedding scaffold, it is shown that 3D constructs containing human blood-derived endothelial colony-forming cells (ECFCs) and bone marrow-derived mesenchymal stem cells (MSCs) generate extensive capillary-like networks in vitro. These vascular structures contain distinct lumens that are formed by the fusion of ECFC intracellular vacuoles in a process of vascular morphogenesis. The process of vascular network formation is dependent on the presence of MSCs, which differentiate into perivascular cells occupying abluminal positions within the network. Importantly, it is shown that implantation of cell-laden GelMA hydrogels into immunodeficient mice results in a rapid formation of functional anastomoses between the bioengineered human vascular network and the mouse vasculature. Furthermore, it is shown that the degree of methacrylation of the GelMA can be used to modulate the cellular behavior and the extent of vascular network formation both in vitro and in vivo. These data suggest that GelMA hydrogels can be used for biomedical applications that require the formation of microvascular networks, including the development of complex engineered tissues. PMID:22907987

  15. Synthesis of Methyl Methacrylate From Coal-Derived Syngas

    SciTech Connect

    Ben W.-L. Jang; Gerald N. Choi; James J. Spivey; Jospeh R. Zoeller; Richard D. Colberg; Samuel S. Tam

    1998-07-27

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter(April-June, 1998), RTI has modified the reactor system including a new preheater and new temperature settings for the preheater. Continuous condensation of formaldehyde with propionic acid were carried out over 10% Nb O /SiO at 300°C without 2 5 2 interruption. Five activity and four regeneration cycles have been completed without plugging or material balance problems. The results show that 10% Nb O /SiO deactivates slowly with time 2 5 2 but can be regenerated, at least four times, to 100% of its original activity with 2% O in nitrogen 2 at 400°C. The cycles continue with consistent 90-95% of carbon balance. The reaction is scheduled to complete with 6 activity cycles and 5 regenerations. Used catalysts will be analyzed with TGA and XPS to determine bulk and surface coke content and coke properties. RTI will start the investigation of effects of propionic acid/formaldehyde ratio on reaction activity and product selectivity over 20% Nb O /SiO catalysts.

  16. Synthesis of acrylates and Methacrylates from Coal-Derived Syngas

    SciTech Connect

    1997-05-12

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy, Federal Energy Technology Center. This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Eastman has focused on the propionate synthesis step. The resultant Mo catalysts work efficiently at much less severe conditions (170{degrees}C and 30 atm) than the conventional Ni catalysts (270{degrees} C and 180 atm). Bechtel has performed an extensive cost analysis which shows that Eastman`s propionate synthesis step is competitive with other technologies to produce the anhydride. Eastman and Bechtel have also compared the RTI- Eastman-Bechtel three-step methanol route to five other process routes to MMA. The results show that the product MMA can be produced at 520/lb, for a 250 Mlb/year MMA plant, and this product cost is competitive to all other process routes to MMA, except propyne carbonylation. In the second step, RTI and Eastman have developed active and stable V-SI-P tertiary metal oxide catalysts, Nb/Si0{sub 2}, and Ta/Si0{sub 2} catalysts for condensation of propionic anhydride or propionic acid with formaldehyde. RTI has demonstrated a novel correlation among the catalyst acid-base properties, condensation reaction yield, and long-term catalyst performance. Eastman and Bechtel have used the RTI experimental results of a 20 percent Nb/Si0{sub 2} catalyst, in terms of reactant conversions, MAA selectivities, and MAA yield, for their economic analysis. Recent research focuses on enhancing the condensation reaction yields, a better understanding of the acid-base property correlation and enhancing the catalyst lifetime.

  17. Synthesis and fluorescence properties of divalent europium-poly(methacrylate containing crown ether structure) complexes

    SciTech Connect

    Higashiyama, N.; Nakamura, H.; Mishima, T.; Shiokawa, J.; Adachi, G. )

    1991-02-01

    This paper reports on divalent europium complexes with poly(methacrylate containing crown ether structure)s, poly(crown ether)s, prepared and their fluorescence properties studied. The polymers used were poly(15-crown-5-methyl methacrylate) (PMA15C5), copoly(15- crown-5-methyl methacrylate-X) (copoly(MA15C5-X)); (X = MMA, EMA, BMA, 2-methoxyethyl methacrylate (MAGI) 3,6,9,12,15- pentaoxahexadecyl methacrylate (MAG5)), poly(18-crown-6- methyl methacrylate) (PMA18C6), and copoly(18-crown-6-methyl methacrylate-MMA) (copoly(MA18C6-MMA)), which were obtained by bulk polymerization. The fluorescence properties of Eu{sup 2+} polymers activated by complexing Eu{sup 2+} ions with crown ether groups were measured in powder form. The Eu{sup 2+}-poly (crown ether)s irradiated by UV light generally gave blue bright emission in the region of 420-465 nm. It was Eu{sup 2+}-copoly(Ma15C5-X); (X = MMA, EMA, and MAG1) that showed the largest emission intensity among the Eu{sup 2+} polymers, and its emission intensity was ca. 20% of that for CaWO{sub 4}:Pb (NBS1026) whose quantum efficiency is about 76%. The intensities of emission for the Eu{sup 2+} polymers containing 15-crown-5 were much larger than that for the ones containing 18-crown-6.

  18. Manufacture of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogel tubes for use as nerve guidance channels.

    PubMed

    Dalton, Paul D; Flynn, Lauren; Shoichet, Molly S

    2002-09-01

    Hydrogel tubes of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) (p(HEMA-co-MMA)) made by liquid-liquid centrifugal casting are being investigated as potential nerve guidance channels in the central nervous system. An important criterion for the nerve guidance channel is that its mechanical properties are similar to those of the spinal cord, where it will be implanted. The formulated p(HEMA-co-MMA) tubes are soft and flexible, consisting of a gel-like outer layer, and an interconnected macroporous, inner layer. The relative thickness of the gel phase to macroporous phase is controlled by the formulation chemistry, and specifically by the ratio of co-monomers, HEMA and MMA. By varying the surface chemistry of the mold within which the tubes are synthesized, tubes were prepared with either a "cracked" or a smooth outer morphology. Tubes with the cracked outer morphology had periodic channels that traversed the wall of the tube, which resulted in a lower modulus than smooth outer morphology tubes, yet likely greater diffusive permeability. For tubes (and not rods) to be formed, phase separation must precede gelation as is detailed in a formulation phase diagram for HEMA, MMA and water. The tensile elastic modulus of p(HEMA-co-MMA) tubes reflected the formulation chemistry, with greater moduli (up to 400 kPa) recorded for tubes having 10 wt% MMA. The p(HEMA-co-MMA) tubes therefore had similar mechanical properties to those of the spinal cord, which has a reported elastic modulus range between 200 and 600 kPa. PMID:12164188

  19. [Formation of ethyl carbamate in umeshu (plum liqueur)].

    PubMed

    Suzuki, K; Kamimura, H; Ibe, A; Tabata, S; Yasuda, K; Nishijima, M

    2001-12-01

    Samples of umeshu, a Japanese plum liqueur made from unripe plums, shochu and crystal sugar, were stored under fluorescent light, in the dark and in the refrigerator. The amount of ethyl carbamate formed in umeshu exposed to light or room temperature was larger than that in the dark or at low temperature. The amount of ethyl carbamate formed in umeshu to which cyanide had been added was larger than that in the absence of added cyanide. Thus, the amount of ethyl carbamate formed in the umeshu was increased by not only light and higher temperature, but also cyanide. Samples of model alcoholic beverages were stored under various conditions using red, yellow and blue cellophanes. The amount of ethyl carbamate formed in the model alcoholic beverage with blue cellophane was larger than in the cases of red and yellow cellophanes. It was found that the amount of ethyl carbamate formed in the model alcoholic beverage was increased by light in the wavelength range of 375-475 nm. PMID:11875819

  20. Allergic contact dermatitis from 2-hydroxyethyl methacrylate in an adhesive on an electrosurgical earthing plate.

    PubMed

    Kanerva, L; Alanko, K

    1998-01-01

    A highly (meth)acrylate-allergic patient underwent surgery because of nodular struma. Three days after her operation she developed an itching dermatitis on her left thigh. She came to our attention 18 days after the operation, because of an oozing, highly pruritic dermatitis, 8 x 19 cm in width on her left thigh, at the site where an electrosurgical earthing plate had been used during the surgery. It was revealed that the pressure-sensitive adhesive of the pad contained 2-hydroxyethyl methacrylate (2-HEMA) to which the patient earlier had had an allergic patch test reaction. The patient was negative on patch testing to other (meth)acrylates present in the pad. Patients should be questioned about possible methacrylate sensitivity before methacrylate-containing electrosurgical earthing plates are used during surgery. Allergic contact dermatitis caused by acrylic adhesives is briefly reviewed. PMID:9854170

  1. Magnetic hydrophilic methacrylate-based polymer microspheres designed for polymerase chain reactions applications.

    PubMed

    Spanová, Alena; Horák, Daniel; Soudková, Eva; Rittich, Bohuslav

    2004-02-01

    Magnetic hydrophilic non-porous P(HEMA-co-EDMA), P(HEMA-co-GMA) and PGMA microspheres were prepared by dispersion (co)polymerization of 2-hydroxyethyl methacrylate (HEMA) and ethylene dimethacrylate (EDMA) or glycidyl methacrylate (GMA) in the presence of several kinds of magnetite. It was found that some components used in the preparation of magnetic carriers interfered with polymerase chain reaction (PCR). Influence of non-magnetic and magnetic microspheres, including magnetite nanoparticles and various components used in their synthesis, on the PCR course was thus investigated. DNA isolated from bacterial cells of Bifidobacterium longum was used in PCR evaluation of non-interfering magnetic microspheres. The method enabled verification of the incorporation of magnetite nanoparticles in the particular methacrylate-based polymer microspheres and evaluation of suitability of their application in PCR. Preferably, electrostatically stabilized colloidal magnetite (ferrofluid) should be used in the design of new magnetic methacrylate-based microspheres by dispersion polymerization. PMID:14698232

  2. Fragrance material review on 2-(p-tolyloxy)ethyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of 2-(p-tolyloxy)ethyl acetate when used as a fragrance ingredient is presented. 2-(p-tolyloxy)ethyl acetate is a member of the fragrance structural group aryl alkyl alcohol simple acid esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(p-tolyloxy)ethyl acetate were evaluated, then summarized, and includes physical properties data. A safety assessment of the entire AAASAE will be published simultaneously with this document. Please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22414652

  3. NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE

    SciTech Connect

    Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan

    2009-09-01

    The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the ground state, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.

  4. Novel catalysts for the environmentally friendly synthesis of methyl methacrylate

    SciTech Connect

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.

    1997-11-01

    The development of a process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas can alleviate the environmental hazards associated with the current commercial MMA technology, the acetone cyanohydrin (ACH) process. A three-step syngas-based process consisted of synthesis of a propionic acid, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) to form MMA. The first two steps, propionic acid synthesis and condensation, are discussed here. The low-temperature, low-pressure process for single-step hydrocarbonylation of ethylene to propionic acid is carried out using a homogeneous iodine-promoted Mo(CO){sub 6} catalyst at pressures (30--70 atm) and temperatures (150--200 C) lower than those reported for other catalysts. Mechanistic investigations suggest that catalysis is initiated by a rate-limiting CO dissociation from Mo(CO){sub 6}. This dissociation appears to be followed by an inner electron-transfer process of an I atom from EtI to the coordinately unsaturated Mo(CO){sub 5}. This homogeneous catalyst for propionate synthesis represents the first case of an efficient carbonylation process based on Cr group metals. The condensation of formaldehyde with propionic acid is carried out by acid-base bifunctional catalysts. As a result of screening over 80 catalytic materials, group V metals supported on an amorphous silica are found to be most effective. A 20% Nb/SiO{sub 2} catalyst appears to be the most active and stable catalyst thus far. Preliminary relations among the reaction yield and catalyst properties indicate that a high surface area and a low overall surface acidity (<50 = mol of NH{sub 3}/g), with a high proportion of the acidity being weak (<350 C desorption of NH{sub 3}), are desirable. Long-term deactivation of V-Si-P, Nb-Si, and Ta-Si catalysts suggests that carbon deposition is the primary cause for activity decay, and the catalyst activity is partially restorable by oxidative regeneration.

  5. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi

    1999-07-19

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. During the April-June quarter(04-06/99) the first in-situ formaldehyde generation from DME and condensation with methyl propionate is demonstrated and the results are summarized. The supported niobium catalyst shows better condensation activity, but supported tungsten catalyst has higher formaldehyde selectivity. The project team has also completed a 200-hour long term test of PA-HCHO condensation over 30% Nb{sub 2}O{sub 5}/SiO{sub 2}. Three activity cycles and two regeneration cycles were carried out. 30% Nb{sub 2}O{sub 5}/SiO{sub 2} showed similar MAA yields as 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. However, the deactivation appears to be slower with 30% Nb{sub 2}O{sub 5}/SiO{sub 2} than 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. An detailed economic analysis of PA-HCHO condensation process for a 250 million lb/yr MMA plant is currently studied by Bechtel. Using the Amoco data-based azeotropic distillation model as the basis, an ASPEN flow sheet model was constructed to simulate the formaldehyde and propionic acid condensation processing section based on RTI's design data. The RTI MAA effluent azeotropic distillation column was found to be much more difficult to converge. The presence of non-condensible gases along with the byproduct DEK (both of which were not presented in

  6. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    SciTech Connect

    BEN W.-L. JANG; GERALD N. CHOI; JAMES J. SPIVEY; JOSPEH R. ZOELLER; RICHARD D. COLBERG

    1998-10-20

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. RTI has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, RTI is currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. Over the last quarter (July-September, 1998), the project team has completed the continuous condensation of formaldehyde with propionic acid over 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. Six activity and five regeneration cycles have been completed. The results show that 10% Nb{sub 2}O{sub 5}/SiO{sub 2} deactivates slowly with time but can be regenerated to its original activity with 2% O{sub 2} in nitrogen over night at 400 C. We have investigated the effects of regeneration, propionic acid/formaldehyde ratio (PA/HCHO = 4.5/1 to 1.5/1) and reaction temperature(280-300 C) on reaction activity and product selectivity over 20% Nb{sub 2}O{sub 5}/SiO{sub 2} catalysts. The regeneration effect on 20% Nb{sub 2}O{sub 5}/SiO{sub 2} is similar to the effect on 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. The regeneration can bring the deactivated catalyst to its original activity. However, the selectivity to MAA decreases with regeneration while the selectivity to DEK and CO{sub 2} increases. When PA/HCHO ratio is decreased from 4.5/1 to 2.25/1 then to 1.5/1 at 300 C the MAA yield decreases but the MAA selectivity first increases then decreases. Decreasing the reaction temperature from 300 C to 280 C decreases the MAA yield from 39.5% to 30.7% but increases the MAA selectivity from 73.7% to 82.2%. The

  7. Synthesis of Acrylates and Methacrylates from Coal-Derived Syngas.

    SciTech Connect

    Gogate, M.R.; Spivey, J.J.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.; Tam, S.S.

    1997-10-17

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the U.S. Department of Energy/Federal Energy Technology Center (DOE/FETC). This three-step process consists of synthesis of a propionate, its condensation with formaldehyde, and esterification of resulting methacrylic acid (MAA) with methanol to produce MMA. Over the last quarter, RTI carried out activity tests on a pure (99 percent) Nb{sub 2}O{sub 5} catalyst, received from Alfa Aesar, under the following experimental conditions: T=300 C; P=4 atm, 72:38:16:4:220 mmol/h, PA:H{sub 2}0:HCHO:CH{sub 3}0H:N{sub 2}; 5-g catalyst charge. For the pure material, the MAA yields (based on HCHO and PA) were at 8.8 and 1.5 percent, clearly inferior compared to those for a 10-percent Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst (20.1 and 4.5 percent). The X-ray diffraction (XRD) patterns of pure Nb{sub 2}O{sub 5} and 20-percent Nb{sub 2}O{sub 5}/Si0{sub 2} that while pure Nb{sub 2}O{sub 5} is very highly crystalline, Si0{sub 2} support for an amorphous nature of the 20 percent Nb{sub 2}O{sub 5}/Si0{sub 2} catalyst the last quarter, RTI also began research on the use of dimethyl ether (DME), product of methanol dehydrocondensation, as an alternate feedstock in MMA synthesis. As a result, formaldehyde is generated either externally or in situ, from DME, in the process envisaged in the contract extension. The initial work on the DME extension of the contract focuses on a tradeoff analysis that will include a preliminary economic analysis of the DME and formaldehyde routes and catalyst synthesis and testing for DME partial oxidation and condensation reactions. Literature guides exist for DME partial oxidation catalysts; however, there are no precedent studies on catalyst development for DME-methyl propionate (MP) condensation reactions, thereby making DME-MP reaction studies a

  8. Temperature-controlled masking/unmasking of cell-adhesive cues with poly(ethylene glycol) methacrylate based brushes.

    PubMed

    Desseaux, Solenne; Klok, Harm-Anton

    2014-10-13

    Thin, thermoresponsive polymer coatings that allow to reversibly modulate cell adhesion and detachment are attractive substrates for cell sheet engineering. Usually, this is accomplished by applying thin poly(N-isopropylacrylamide) (PNIPAM) coatings, which allow cell adhesion via nonspecific interactions above the collapse temperature (T(T)) of the surface-attached polymer and cell detachment upon cooling below T(T). This Article presents an alternative, thermoresponsive polymer platform that is based on 2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA) containing copolymer brushes prepared via surface-initiated atom transfer radical polymerization (SI-ATRP). These brushes are interesting as they gradually collapse and dehydrate upon increasing the temperature from 10 to 40 °C, yet resist nonspecific adhesion of cells over this entire temperature window. The MEO2MA based brushes presented here were modified via a two-step postpolymerization modification protocol to introduce cell-adhesive RGD containing peptide ligands. The possibility to reversibly control the swelling and collapse of these brush films by varying temperature allows to modulate the effectively available surface concentration of these cell-adhesive cues and thus provides a way to mask/unmask their biological activity. As a first proof of concept, this Article demonstrates that these MEO2MA brush copolymer films enable integrin-mediated adhesion of 3T3 fibroblasts at 37 °C and allow release of these cells by cooling to 23 °C. The use of cell-adhesive ligands, which can be thermoreversibly masked/unmasked, is attractive as it enables the use of serum-free cell culture conditions. This is advantageous since it avoids possible concerns regarding eventual toxicity and immunological side effects of serum proteins and also provides opportunities to select for particular cell types and for enhanced control over cell stimulation and differentiation. PMID:25208302

  9. Tissue reaction to methyl methacrylate monomer. A comparative study in the rabbit's ear on the toxicity of methyl methacrylate monomer of varying composition.

    PubMed

    Linder, L

    1976-02-01

    The aim of the present investigation was to evaluate if a bone cement monomer with a high concentration of accelerator (N,N-dimethyl-p-toluidine) is more toxic than a methyl methacrylate monomer, free from accelerator. 1) No difference in the acute local toxicity between CMW, Simplex-P and pure methyl methacrylate monomer was seen. 2) By gas chromatography. N,N-dimethyl-p-toluidine was shown to be water soluble to a small extent. Any bone cement monomer in current use can be fully dissolved in saline to a concentration of about 1 per cent. PMID:1266590

  10. Nitrosamine-induced carcinogenesis. The alkylation of N-7 of guanine of nucleic acids of the rat by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate

    PubMed Central

    Swann, P. F.; Magee, P. N.

    1971-01-01

    1. The extent of ethylation of N-7 of guanine in the nucleic acids of rat tissue in vivo by diethylnitrosamine, N-ethyl-N-nitrosourea and ethyl methanesulphonate was measured. 2. All compounds produced measurable amounts of 7-ethyl-guanine. 3. A single dose of diethylnitrosamine or N-ethyl-N-nitrosourea produced tumours of the kidney in the rat. Three doses of ethyl methanesulphonate produced kidney tumours, but a single dose did not. 4. A single dose of diethylnitrosamine produced twice as much ethylation of N-7 of guanine in DNA of kidney as did N-ethyl-N-nitrosourea. A single dose of both compounds induced kidney tumours, although of a different histological type. 5. A single dose of ethyl methanesulphonate produced ten times as much ethylation of N-7 of guanine in kidney DNA as did N-ethyl-N-nitrosourea without producing tumours. 6. The relevance of these findings to the hypothesis that alkylation of a cellular component is the mechanism of induction of tumours by nitroso compounds is discussed. PMID:5145908

  11. Assistance of ethyl glucuronide and ethyl sulfate in the interpretation of postmortem ethanol findings.

    PubMed

    Krabseth, Hege; Mørland, Jørg; Høiseth, Gudrun

    2014-09-01

    Postmortem ethanol formation is a well-known problem in forensic toxicology. The aim of this study was to interpret findings of ethanol in blood, in a large collection of forensic autopsy cases, by use of the nonoxidative ethanol metabolites, ethyl glucuronide (EtG), and ethyl sulfate (EtS). In this study, according to previously published literature, antemortem ethanol ingestion was excluded in EtS-negative cases. Among 493 ethanol-positive forensic autopsy cases, collected during the study period, EtS was not detected in 60 (12 %) of the cases. Among cases with a blood alcohol concentration (BAC) of ≤ 0.54 g/kg, antemortem ethanol ingestion was excluded in 38 % of the cases, while among cases with a BAC of ≥ 0.55 g/kg, antemortem ethanol ingestion was excluded in 2.2 % of the cases. For all cases where ethanol was measured at a concentration >1.0 g/kg, EtS was detected. The highest blood ethanol concentration in which EtS was not detected was 1.0 g/kg. The median concentrations of EtG and EtS in blood were 9.5 μmol/L (range: not detected (n.d.) 618.1) and 9.2 μmol/L (range: n.d. 182.5), respectively. There was a statistically significant positive correlation between concentration levels of ethanol and of EtG (Spearman's rho=0.671, p<0.001) and EtS (Spearman's rho=0.670, p<0.001), respectively. In conclusion, this study showed that in a large number of ethanol-positive forensic autopsy cases, ethanol was not ingested before the time of death, particularly among cases where ethanol was present in lower blood concentrations. Routine measurement of EtG and EtS should therefore be recommended, especially in cases with BAC below 1 g/kg. PMID:24935750

  12. Blood kinetics of ethyl glucuronide and ethyl sulphate in heavy drinkers during alcohol detoxification.

    PubMed

    Høiseth, Gudrun; Morini, Luca; Polettini, Aldo; Christophersen, Asbjørg; Mørland, Jørg

    2009-07-01

    Studies of ethyl glucuronide (EtG) blood kinetics have so far been performed on healthy volunteers with ingestion of low to moderate doses of ethanol. These data are not necessarily transferable to heavy drinkers where the consumed doses of ethanol are much higher. The aim of this study was to investigate the pharmacokinetics of EtG and ethyl sulphate (EtS) in blood in heavy drinkers after termination of alcohol ingestion. Sixteen patients from an alcohol withdrawal clinic were included directly after admission. Time of end of drinking, estimated daily intake of ethanol (EDI) and medical history were recorded. Three to five blood samples over 20-43 h were collected from each patient subsequent to admission. The median EDI was 172 g (range 60-564). The first sample was collected median 2.5 h after end of drinking (range 0.5-23.5). Two patients had levels of EtG and EtS below LOQ in all samples, the first collected 19.25 and 23.5 h after cessation of drinking, respectively. Of the remaining 14 patients, one subject, suffering from both renal and hepatic disease, showed concentrations of EtG and EtS substantially higher than the rest of the material. This patient's initial value of EtG was 17.9 mg/L and of EtS 5.9 mg/L, with terminal elimination half lives of 11.9 h for EtG and 12.5 h for EtS. Among the remaining 13 patients, the initial median values were 0.7 g/L (range 0-3.7) for ethanol, 1.7 mg/L (range 0.1-5.9) for EtG and 0.9 mg/L (range 0.1-1.9) for EtS. Elimination occurred with a median half-life of 3.3 h for EtG (range 2.6-4.3) and 3.6 h for EtS (range 2.7-5.4). In conclusion, elimination of EtG in heavy drinkers did not significantly differ from healthy volunteers, and EtS appeared to have similar elimination rate. In the present work, there was one exception to this, and we propose that this could be explained by the patient's renal disease, which would delay excretion of these conjugated metabolites. PMID:19395207

  13. Adsorption of paraquat using methacrylic acid-modified rice husk.

    PubMed

    Hsu, Shih-Tong; Pan, Ting-Chung

    2007-12-01

    This work investigates the adsorption of paraquat from aqueous medium using a methacrylic acid (MAA)-modified rice husk. The carboxyl groups were chemically bound to the surface of the rice husk by graft copolymerization using Fenton's reagent as a redox initiator. The graft copolymerization was examined to determine the H(2)O(2) concentration and the amount of MAA monomer used. FT-IR spectra confirmed the presence of carbonyl groups on the structural units of the rice husk derivative. The MAA-modified rice husks were hydrolyzed to sodium salt and used to adsorb paraquat. The adsorption was rapid in the first few minutes and quickly reached equilibrium. Equilibrium adsorption data are more consistent with the Langmuir isotherm equation than with the Freundlich equation. The maximum adsorption capacity of modified rice husks was 317.7mg/g-adsorbent. This value clearly exceeds the 60mg/g of Fuller's earth and the 90mg/g of activated carbon, which are the most commonly used binding agents for paraquat. PMID:17303413

  14. Directed endothelial cell morphogenesis in micropatterned gelatin methacrylate hydrogels.

    PubMed

    Nikkhah, Mehdi; Eshak, Nouran; Zorlutuna, Pinar; Annabi, Nasim; Castello, Marco; Kim, Keekyoung; Dolatshahi-Pirouz, Alireza; Edalat, Faramarz; Bae, Hojae; Yang, Yunzhi; Khademhosseini, Ali

    2012-12-01

    Engineering of organized vasculature is a crucial step in the development of functional and clinically relevant tissue constructs. A number of previous techniques have been proposed to spatially regulate the distribution of angiogenic biomolecules and vascular cells within biomaterial matrices to promote vascularization. Most of these approaches have been limited to two-dimensional (2D) micropatterned features or have resulted in formation of random vasculature within three-dimensional (3D) microenvironments. In this study, we investigate 3D endothelial cord formation within micropatterned gelatin methacrylate (GelMA) hydrogels with varying geometrical features (50-150 μm height). We demonstrated the significant dependence of endothelial cells proliferation, alignment and cord formation on geometrical dimensions of the patterned features. The cells were able to align and organize within the micropatterned constructs and assemble to form cord structures with organized actin fibers and circular/elliptical cross-sections. The inner layer of the cord structure was filled with gel showing that the micropatterned hydrogel constructs guided the assembly of endothelial cells into cord structures. Notably, the endothelial cords were retained within the hydrogel microconstructs for all geometries after two weeks of culture; however, only the 100 μm-high constructs provided the optimal microenvironment for the formation of circular and stable cord structures. Our findings suggest that endothelial cord formation is a preceding step to tubulogenesis and the proposed system can be used to develop organized vasculature for engineered tissue constructs. PMID:23018132

  15. Directed Endothelial Cell Morphogenesis in Micropatterned Gelatin Methacrylate Hydrogels

    PubMed Central

    Nikkhah, Mehdi; Eshak, Nouran; Zorlutuna, Pinar; Annabi, Nasim; Castello, Marco; Kim, Keekyoung; Dolatshahi-Pirouz, Alireza; Edalat, Faramarz; Bae, Hojae; Yang, Yunzhi; Khademhosseini, Ali

    2013-01-01

    Engineering of organized vasculature is a crucial step in the development of functional and clinically relevant tissue constructs. A number of previous techniques have been proposed to spatially regulate the distribution of angiogenic biomolecules and vascular cells within biomaterial matrices to promote vascularization. Most of these approaches have been limited to two-dimensional (2D) micropatterned features or have resulted in formation of random vasculature within three-dimensional (3D) microenvironments. In this study, we investigate 3D endothelial cord formation within micropatterned gelatin methacrylate (GelMA) hydrogels with varying geometrical features (50–150 µm height). We demonstrated the significance dependence of endothelial cells proliferation, alignment and cord formation on geometrical dimensions of the patterned features. The cells were able to align and organize within the micropatterned constructs and assemble to form cord structures with organized actin fibers and circular/elliptical cross-sections. The inner layer of the cord structure was filled with gel showing that the micropatterned hydrogel constructs guided the assembly of endothelial cells into cord structures. Notably, the endothelial cords were retained within the hydrogel microconstructs for all geometries after two weeks of culture; however, only the 100 µm-high constructs provided the optimal microenvironment for the formation of circular and stable cord structures. Our findings suggest that endothelial cord formation is a preceding step to tubulogenesis and the proposed system can be used to develop organized vasculature for engineered tissue constructs. PMID:23018132

  16. Control of cell adhesion on poly(methyl methacrylate).

    PubMed

    Patel, Shyam; Thakar, Rahul G; Wong, Josh; McLeod, Stephen D; Li, Song

    2006-05-01

    Keratoprostheses have been constructed from a wide variety of transparent materials, including poly(methyl methacrylate) (PMMA). However, the success of keratoprosthesis has been plagued by numerous shortcomings that include the weakening of the implant-host interface due to weak cell adhesion and opaque fibrous membrane formation over the inner surface of the implant due to fibroblast attachment. An effective solution requires a surface modification that would selectively allow enhanced cell attachment at the implant-host interface and reduced cell attachment over the interior surface of the implant. Here, we have developed a novel and simple peptide conjugation scheme to modify PMMA surfaces, which allowed for region-specific control of cell adhesion. This method uses di-amino-PEG, which can be grafted onto PMMA using hydrolysis or aminolysis method. PEG can resist cell adhesion and protein adsorption. The functionalization of grafted di-amino-PEG molecules with RGD peptide not only restored cell adhesion to the surfaces, but also enhanced cell attachment and spreading as compared to untreated PMMA surfaces. Long-term cell migration and micropatterning studies clearly indicated that PEG-PMMA surfaces with and without RGD conjugation can be used to differentiate cell adhesion and control cell attachment spatially on PMMA, which will have potential applications in the modification of keratoprostheses. PMID:16439014

  17. Methyl methacrylate and respiratory sensitization: A Critical review

    PubMed Central

    Borak, Jonathan; Fields, Cheryl; Andrews, Larry S; Pemberton, Mark A

    2011-01-01

    Methyl methacrylate (MMA) is a respiratory irritant and dermal sensitizer that has been associated with occupational asthma in a small number of case reports. Those reports have raised concern that it might be a respiratory sensitizer. To better understand that possibility, we reviewed the in silico, in chemico, in vitro, and in vivo toxicology literature, and also epidemiologic and occupational medicine reports related to the respiratory effects of MMA. Numerous in silico and in chemico studies indicate that MMA is unlikely to be a respiratory sensitizer. The few in vitro studies suggest that MMA has generally weak effects. In vivo studies have documented contact skin sensitization, nonspecific cytotoxicity, and weakly positive responses on local lymph node assay; guinea pig and mouse inhalation sensitization tests have not been performed. Cohort and cross-sectional worker studies reported irritation of eyes, nose, and upper respiratory tract associated with short-term peaks exposures, but little evidence for respiratory sensitization or asthma. Nineteen case reports described asthma, laryngitis, or hypersensitivity pneumonitis in MMA-exposed workers; however, exposures were either not well described or involved mixtures containing more reactive respiratory sensitizers and irritants.The weight of evidence, both experimental and observational, argues that MMA is not a respiratory sensitizer. PMID:21401327

  18. Purification of large plasmids with methacrylate monolithic columns.

    PubMed

    Krajnc, Nika Lendero; Smrekar, Franci; Cerne, Jasmina; Raspor, Peter; Modic, Martina; Krgovic, Danijela; Strancar, Ales; Podgornik, Ales

    2009-08-01

    The rapid evolution of gene therapy and DNA vaccines results in an increasing interest in producing large quantities of pharmaceutical grade plasmid DNA. Most current clinical trials involve plasmids of 10 kb or smaller in size, however, future requirements for multigene vectors including extensive control regions may require the production of larger plasmids, e. g., 20 kb and bigger. The objective of this study was to examine certain process conditions for purification of large plasmids with the size of up to 93 kb. Since there is a lack of knowledge about production and purification of bigger plasmid DNA, cell lysis and storage conditions were investigated. The impact of chromatographic system and methacrylate monolithic column on the degradation of plasmid molecules under nonbinding conditions at different flow rates was studied. Furthermore, capacity measurements varying salt concentration in loading buffer were performed and the capacities up to 13 mg of plasmid per mL of the monolithic column were obtained. The capacity flow independence in the range from 130 to 370 cm/h was observed. Using high resolution monolithic column the separation of linear and supercoiled isoforms of large plasmids was obtained. Last but not least, since the baseline separation of RNA and pDNA was achieved, the one step purification on larger CIM DEAE 8 mL tube monolithic column was performed and the fractions were analyzed by CIM analytical monolithic columns. PMID:19598166

  19. IR laser ablation of doped poly(methyl methacrylate)

    NASA Astrophysics Data System (ADS)

    Gaspard, S.; Oujja, M.; Rebollar, E.; Walczak, M.; Díaz, L.; Santos, M.; Castillejo, M.

    2007-05-01

    We investigate the TEA CO 2 laser ablation of films of poly(methyl methacrylate), PMMA, with average MW 2.5, 120 and 996 kDa doped with photosensitive compounds iodo-naphthalene (NapI) and iodo-phenanthrene (PhenI) by examining the induced morphological and physicochemical modifications. The films casted on CaF 2 substrates were irradiated with a pulsed CO 2 laser (10P(20) line at 10.59 μm) in resonance with vibrational modes of PMMA and of the dopants at fluences up to 6 J/cm 2. Laser induced fluorescence probing of photoproducts in a pump and probe configuration is carried out at 266 nm. Formation of naphthalene (NapH) and phenanthrene (PhenH) is observed in NapI and PhenI doped PMMA, respectively, with relatively higher yields in high MW polymer, in similarity with results obtained previously upon irradiation in the UV at 248 nm. Above threshold, formation of photoproducts is nearly complete after 200 ms. As established via optical microscopy, bubbles are formed in the irradiated areas with sizes that depend on polymer MW and filaments are observed to be ejected out of the irradiated volume in the samples made with high MW polymer. The implications of these results for the mechanisms of polymer IR laser ablation are discussed and compared with UV range studies.

  20. Characterization of methacrylate chromatographic monoliths bearing affinity ligands.

    PubMed

    Černigoj, Urh; Vidic, Urška; Nemec, Blaž; Gašperšič, Jernej; Vidič, Jana; Lendero Krajnc, Nika; Štrancar, Aleš; Podgornik, Aleš

    2016-09-16

    We investigated effect of immobilization procedure and monolith structure on chromatographic performance of methacrylate monoliths bearing affinity ligands. Monoliths of different pore size and various affinity ligands were prepared and characterized using physical and chromatographic methods. When testing protein A monoliths with different protein A ligand densities, a significant nonlinear effect of ligand density on dynamic binding capacity (DBC) for IgG was obtained and accurately described by Langmuir isotherm curve enabling estimation of protein A utilization as a function of ligand density. Maximal IgG binding capacity was found to be at least 12mg/mL exceeding theoretical monolayer adsorption value of 7.8mg/mL assuming hexagonal packing and IgG hydrodynamic diameter of 11nm. Observed discrepancy was explained by shrinkage of IgG during adsorption on protein A experimentally determined through calculated adsorbed IgG layer thickness of 5.4nm from pressure drop data. For monoliths with different pore size maximal immobilized densities of protein A as well as IgG dynamic capacity linearly correlates with monolith surface area indicating constant ligand utilization. Finally, IgGs toward different plasma proteins were immobilized via the hydrazide coupling chemistry to provide oriented immobilization. DBC was found to be flow independent and was increasing with the size of bound protein. Despite DBC was lower than IgG capacity to immobilized protein A, ligand utilization was higher. PMID:27554023

  1. Manufacture of poly(methyl methacrylate) microspheres using membrane emulsification.

    PubMed

    Bux, Jaiyana; Manga, Mohamed S; Hunter, Timothy N; Biggs, Simon

    2016-07-28

    Accurate control of particle size at relatively narrow polydispersity remains a key challenge in the production of synthetic polymer particles at scale. A cross-flow membrane emulsification (XME) technique was used here in the preparation of poly(methyl methacrylate) microspheres at a 1-10 l h(-1) scale, to demonstrate its application for such a manufacturing challenge. XME technology has previously been shown to provide good control over emulsion droplet sizes with careful choice of the operating conditions. We demonstrate here that, for an appropriate formulation, equivalent control can be gained for a precursor emulsion in a batch suspension polymerization process. We report here the influence of key parameters on the emulsification process; we also demonstrate the close correlation in size between the precursor emulsion and the final polymer particles. Two types of polymer particle were produced in this work: a solid microsphere and an oil-filled matrix microcapsule.This article is part of the themed issue 'Soft interfacial materials: from fundamentals to formulation'. PMID:27298430

  2. Nonsolvents-induced swelling of poly(methyl methacrylate) nanoparticles.

    PubMed

    Shundo, Atsuomi; Hori, Koichiro; Penaloza, David P; Yoshihiro, Kazuki; Annaka, Masahiko; Tanaka, Keiji

    2013-10-21

    Polymer nanoparticles have been used in a wide variety of applications. In most of these applications, they are generally dispersed in a non-solvent. However, the effect of the non-solvent on the structure, physical properties and function of the nanoparticles has not yet ever taken into account. In this study, monodispersed poly(methyl methacrylate) (PMMA) nanoparticles were prepared by a surfactant-free emulsion polymerization. The PMMA nanoparticles were dispersed in water and in methanol, both typical non-solvents for PMMA, so that we could discuss the effect of the non-solvent on the nanoparticles. Dynamic light scattering measurements revealed that the hydrodynamic radius of the PMMA nanoparticles in methanol was larger than the same PMMA dispersed in water. Their DLS values were also larger than the radius of the nanoparticles measured by atomic force microscopy. When pyrene was dispersed in methanol with the PMMA nanoparticles, it was incorporated into the nanoparticles. These results clearly indicate that non-solvent molecules can be sorbed into polymer nanoparticles because the area of the interface, where polymer segments might be dissolved into liquid phases, as the total volume is quite larger for such nanoparticles. Therefore, based on our findings, it can be arguably established that the present assumption for a polymer not to be swollen in its non-solvent is not necessarily true. PMID:23955567

  3. Effect of CaCO₃/HCl pretreatment on the surface modification of chitin gel beads via graft copolymerization of 2-hydroxy ethyl methacrylate and 4-vinylpyridine.

    PubMed

    Yalinca, Zulal; Mohammed, Dana Ali Kader; Hadi, Jihad M; Yilmaz, Elvan

    2016-01-01

    Although chitin, poly(N-acetylglucosamine), possesses considerable potential as a biomaterial, it has not been as thoroughly studied as its derivative chitosan. In this study, the potential of chitin gel beads has been evaluated for surface modification via vinyl polymer grafting. Grafting behavior of two well-established vinyl monomers, namely 2-hydroxyethylmethacrylate (HEMA) and 4-vinylpyridine (4-VP) were investigated using cerium (IV) ammonium nitrate as the redox initiator with the aim of obtaining chemically functionalized more hydrophilic chitin surfaces. The intractable nature of chitin, which is one of its primary drawbacks as a grafting substrate was overcome by applying a CaCO3 treatment during bead preparation. The maximum grafting percentage of poly(HEMA) onto chitin bead without CaCO3 treatment was found to be 65%, while the value for CaCO3 treated chitin beads was 515%. The maximum grafting yield of poly(4-VP) on to CaCO3 treated chitin powder was 380% at optimum conditions. The grafting system was extensively characterized before and after grafting by FT-IR, SEM, C-13 NMR and XRD analyses. Significant improvement on the swelling capacities of chitin based gel beads in aqueous acidic, basic and neutral media was obtained. An account of the pros and cons of the system has been presented. PMID:26500177

  4. Preparation and Properties of Novel Dentin Adhesives with Esterase Resistance

    PubMed Central

    Park, Jong-Gu; Ye, Qiang; Topp, Elizabeth M.; Kostoryz, Elisabet L.; Wang, Yong; Kieweg, Sarah L.; Spencer, Paulette

    2012-01-01

    A new methacrylate monomer, trimethylolpropane mono allyl ether dimethacrylate (TMPEDMA), was synthesized and evaluated. This branched methacrylate was designed to increase esterase-resistance when incorporated into conventional HEMA (2-hydroxyethyl methacrylate)/BisGMA (2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane) dental adhesives. The new adhesives, HEMA/BisGMA/TMPEDMA in a 45/30/25 (w/w) ratio were formulated with H2O at 0 (A0T) and 8 wt % water (A8T) and compared with control adhesives (HEMA/BisGMA, 45/55 (w/w), at 0 (A0) and 8 wt % (A8) water). Camphoroquinone (CQ), 2-(dimethylamino) ethyl methacrylate and diphenyliodonium hexafluorophosphate were used as photoinitiators. The new adhesives showed a degree of conversion comparable with the control and improved modulus and glass transition temperature (Tg). Exposure of photopolymerized discs to porcine liver esterase for up to eight days showed that the net cumulative methacrylic acid (MAA) release in adhesives formulated with the new monomer and 8% water (A8T: 182 μg/mL) was dramatically (P < 0.05) decreased in comparison to the control (A8: 361.6 μg/mL). The results demonstrate that adhesives made with the new monomer and cured in water to simulate wet bonding are more resistant to esterase than conventional HEMA/BisGMA adhesive. PMID:22919119

  5. Well-defined inorganic/organic nanocomposite by nano silica core-poly(methyl methacrylate/butylacrylate/trifluoroethyl methacrylate) shell.

    PubMed

    Chang, Gang; He, Ling; Zheng, Wei; Pan, Aizhao; Liu, Jing; Li, Yingjun; Cao, Ruijun

    2013-04-15

    The novel inorganic/organic core-shell SiO2/P(MMA/BA/3FMA) nanocomposite for coating application is synthesized in this paper by seed emulsion polymerization, in which the inorganic phase is composed of nano-SiO2 modified by vinyl-trimethoxysilane (VMS) or γ-methacryloxy propyl trimethoxylsilane (MPMS), and the organic phase is made of terpolymer by 2,2,2-trifluoroethyl methacrylate (3FMA), methyl methacrylate (MMA), and n-butyl acrylate (BA). The chemical structure of SiO2/P(MMA/BA/3FMA) is characterized by FTIR. The effect of surfactant polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS)/octyl phenyl polyoxyethylene ether (TX-10), sodium dodecyl benzene sulfonate (SDBS)/TX-10 and sodium hexametaphosphate (SHMP) on the grafting ratio (GR) of VMS and MPMS, the dispersion of nano-SiO2 particles and the film properties of SiO2/P(MMA/BA/3FMA) are investigated by TGA, DLS, TEM, SEM, and XPS. The morphology variation and the particle size distributions of SiO2/P(MMA/BA/3FMA) with the content of surfactant and P(MMA/BA/3FMA) are characterized. It is found that MPMS is more effective than VMS in improving GR and the dispersion of nano-SiO2 particles. The surfactants are favor of gaining the higher GR in the multilayer grafted nano-SiO2, especially SDS/TX-10 for 17.6% GR. The morphology of SiO2/P(MMA/BA/3FMA) is controlled by the amount of SDS/TX-10 and P(MMA/BA/3FMA) as the core-shell particles, the stacked pomegranate seed with multicore and the multicore-single shell structure when w(MMA)/w(BA)/w(3FMA)=1.3/1/1. Among the different surfactants, SDBS/TX-10 and PVP could give the monodispersing nano-SiO2 in the terpolymer matrix of the films, but SDS/TX-10 and SDBS/TX-10 could perform the fluorine-rich surface. PMID:23403111

  6. Ethyl glucuronide and ethyl sulfate in meconium and hair-potential biomarkers of intrauterine exposure to ethanol.

    PubMed

    Morini, L; Marchei, E; Vagnarelli, F; Garcia Algar, O; Groppi, A; Mastrobattista, L; Pichini, S

    2010-03-20

    This study investigated ethyl glucuronide (EtG) and ethyl sulfate (EtS) concentration in meconium and in maternal and neonatal hair (HEtG and HFAEEs, respectively) as potential markers of intrauterine exposure to ethanol together with meconium fatty acid ethyl esters (FAEEs) in a cohort of 99 mother-infant dyads, 49 coming from the Arcispedale of Reggio Emilia (Italy) and 50 from the Hospital del Mar of Barcelona (Spain). FAEEs, EtG and EtS were measured in meconium samples using liquid chromatography-tandem mass spectrometry. A head space-solid phase microextraction-gas chromatography-mass spectrometry was used to test HEtG and HFAEEs in hair samples from mothers and their newborns. Eighty-two meconium samples (82.8%) tested positive for EtG, 19 (19.2%) for EtS while 22 (22.2%) showed FAEEs levels higher than 2 nmol/g, the cut-off used to differentiate daily maternal ethanol consumption during pregnancy from occasional or no use. Although EtG and EtS in meconium did not correlate with total FAEEs concentration, a good correlation between EtG, EtS and ethyl stearate was observed. Moreover, EtG correlated well with ethyl palmitoleate, while EtS with ethyl laurate, myristate and linolenate. Neither maternal nor neonatal hair appears as good predictors of gestational ethanol consumption and subsequent fetal exposure in these mother-infant dyads. In conclusion, these data show that meconium is so far the best matrix in evaluating intrauterine exposure to ethanol, with EtG and EtS being potentially good alternative biomarkers to FAEEs. PMID:20060246

  7. Steric Effects in Ionic Pairing and Polyelectrolyte Interdiffusion within Multilayered Films: A Neutron Reflectometry Study

    SciTech Connect

    Xu, Li; Ankner, John Francis; Sukhishvili, Prof. Svetlana A.

    2011-01-01

    Using a series of polycations synthesized by atom transfer radical polymerization (ATRP), we investigate the effects of the polymer charge density and hydrophobicity on salt-induced interdiffusion of polymer layers within polyelectrolyte multilayer (PEM) films. Polycations with two distinct hydrophobicities and various quaternization degrees (QPDMA and QPDEA) were derived from parent polymers of matched molecular weights poly(2-(dimethylamino)ethyl methacrylate) (PDMA) and poly(2-(diethylamino)ethyl methacrylate) (PDEA) by quaternization with either methyl or ethyl sulfate. Multilayers of these polycations with polystyrene sulfonate (PSS) were assembled in low-salt conditions, and annealed in NaCl solutions to induce layer intermixing. As revealed by neutron reflectometry (NR), polycations with lower charge density resulted in a faster decay of film structure with distance from the substrate. Interestingly, when comparing polymer mobility in QPDEA/PSS and QPDMA/PSS films, layer intermixing was faster in the case of more hydrophobic QPDEA as compared to QPDMA, because of the weaker ionic pairing (due to the presence of a bulky ethyl spacer) between QPDEA and PSS.

  8. Poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) Brushes as Peptide/Protein Microarray Substrate for Improving Protein Binding and Functionality.

    PubMed

    Lei, Zhen; Gao, Jiaxue; Liu, Xia; Liu, Dianjun; Wang, Zhenxin

    2016-04-27

    We developed a three-dimensional (3D) polymer-brush substrate for protein and peptide microarray fabrication, and this substrate was facilely prepared by copolymerization of glycidyl methacrylate (GMA) and 2-hydroxyethyl methacrylate (HEMA) monomers via surface-initiated atom transfer radical polymerization (SI-ATRP) on a glass slide. The performance of obtained poly(glycidyl methacrylate-co-2-hydroxyethyl methacrylate) (P(GMA-HEMA)) brush substrate was assessed by binding of human IgG with rabbit antihuman IgG antibodies on a protein microarray and by the determination of matrix metalloproteinase (MMP) activities on a peptide microarray. The P(GMA-HEMA) brush substrate exhibited higher immobilization capacities for proteins and peptides than those of a two-dimensional (2D) planar epoxy slide. Furthermore, the sensitivity of the P(GMA-HEMA) brush-based microarray on rabbit antihuman IgG antibody detection was much higher than that of its 2D counterpart. The enzyme activities of MMPs were determined specifically with a low detection limit of 6.0 pg mL(-1) for MMP-2 and 5.7 pg mL(-1) for MMP-9. By taking advantage of the biocompatibility of PHEMA, the P(GMA-HEMA) brush-based peptide microarray was also employed to evaluate the secretion of MMP-2 and MMP-9 by cells cultured off the chip or directly on the chip, and satisfactory results were obtained. PMID:27049528

  9. Surface modification of silk fibroin fibers with poly(methyl methacrylate) and poly(tributylsilyl methacrylate) via RAFT polymerization for marine antifouling applications.

    PubMed

    Buga, Mihaela-Ramona; Zaharia, Cătălin; Bălan, Mihai; Bressy, Christine; Ziarelli, Fabio; Margaillan, André

    2015-06-01

    In this study, silk fibroin surface containing hydroxyl and aminogroups was firstly modified using a polymerizable coupling agent 3-(trimethoxysilyl) propyl methacrylate (MPS), in order to induce vinyl groups onto the fiber surface. The reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization of methyl methacrylate (MMA) and tributylsilyl methacrylate (TBSiMA) through the immobilized vinyl bond on the silk fibroin surface in the presence of 2-cyanoprop-2-yl dithiobenzoate (CPDB) as chain-transfer agent and 2,2'-azobis(isobutyronitrile) (AIBN) as initiator was conducted in toluene solution at 70°C for 24h. The structure and properties of the modified fiber were characterized by Fourier Transform Infrared Spectroscopy, (13)C, (29)Si Nuclear Magnetic Resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), confirming the presence of the coupling molecule and the methacrylate groups onto the silk fibroin fiber surface. Molecular weight distributions were assessed by triple detection size exclusion chromatography (TD-SEC) in order to verify the livingness of the polymerization. PMID:25842130

  10. Dissociation of the Ethyl Radical: An Exercise in Computational Chemistry

    ERIC Educational Resources Information Center

    Nassabeh, Nahal; Tran, Mark; Fleming, Patrick E.

    2014-01-01

    A set of exercises for use in a typical physical chemistry laboratory course are described, modeling the unimolecular dissociation of the ethyl radical to form ethylene and atomic hydrogen. Students analyze the computational results both qualitatively and quantitatively. Qualitative structural changes are compared to approximate predicted values…

  11. Reactivity of 2-ethyl-1-hexanol in the atmosphere.

    PubMed

    Gallego-Iniesta García, María Paz; Moreno Sanroma, Alberto; Martín Porrero, María Pilar; Tapia Valle, Araceli; Cabañas Galán, Beatriz; Salgado Muñoz, María Sagrario

    2010-04-01

    Rate coefficients at room temperature for the reaction of 2-ethyl-1-hexanol with OH and NO(3) radicals and with Cl atoms have been determined in a 150 L PTFE chamber using GC-FID/SPME and FTIR as detection systems. The rate coefficients k (in units of cm(3) molecule(-1) s(-1)) obtained were: (1.13 +/- 0.31) 10(-11) for the OH reaction, (2.93 +/- 0.92) 10(-15) for the NO(3) reaction and (1.88 +/- 0.25) 10(-10) for the Cl reaction. Despite the high concentrations of 2-ethyl-1-hexanol, especially in indoor air, this is the first kinetic study carried out to date for these reactions. The results are consistent with the expected reactivity given the chemical structure of 2-ethyl-1-hexanol. Calculated atmospheric lifetimes reveal that the dominant loss process for 2-ethyl-1-hexanol is clearly the daytime reaction with the hydroxyl radical. PMID:20237722

  12. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700 Methyl ethyl ketoxime. (a) Identification of test substance. (1... signs of cytotoxicity (e.g., a change in the ratio of polychromatic to normochromatic erythrocytes)...

  13. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700 Methyl ethyl ketoxime. (a) Identification of test substance. (1... signs of cytotoxicity (e.g., a change in the ratio of polychromatic to normochromatic erythrocytes)...

  14. 40 CFR 799.2700 - Methyl ethyl ketoxime.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Methyl ethyl ketoxime. 799.2700 Section 799.2700 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) IDENTIFICATION OF SPECIFIC CHEMICAL SUBSTANCE AND MIXTURE TESTING REQUIREMENTS Specific Chemical Test Rules § 799.2700...

  15. 76 FR 31479 - Pyraflufen-ethyl; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... Federal Register of June 23, 2010 (75 FR 35801) (FRL-8831- 3), EPA issued a notice pursuant to section 408...- ethyl. C. Revisions to Petitioned-for Tolerances In the Federal Register of December 8, 2010 (75 FR..., entitled Regulatory Planning and Review (58 FR 51735, ] October 4, 1993). Because this final rule has...

  16. 77 FR 41346 - Trinexapac-ethyl; Proposed Pesticide Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... tolerance table for trinexapac-ethyl that was published in the Federal Register on March 2, 2012 (77 FR... Planning and Review'' (58 FR 51735, October 4, 1993). Because this proposed rule has been exempted from..., Distribution, or Use'' (66 FR 28355, May 22, 2001). This proposed rule does not contain any...

  17. Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment

    ERIC Educational Resources Information Center

    Leslie, Ray; Leeb, Elaine; Smith, Robert B.

    2012-01-01

    A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…

  18. Kinetics of Ethyl Acetate Synthesis Catalyzed by Acidic Resins

    ERIC Educational Resources Information Center

    Antunes, Bruno M.; Cardoso, Simao P.; Silva, Carlos M.; Portugal, Ines

    2011-01-01

    A low-cost experiment to carry out the second-order reversible reaction of acetic acid esterification with ethanol to produce ethyl acetate is presented to illustrate concepts of kinetics and reactor modeling. The reaction is performed in a batch reactor, and the acetic acid concentration is measured by acid-base titration versus time. The…

  19. Enantioselective Metabolism of Quizalofop-Ethyl in Rat

    PubMed Central

    Liang, Yiran; Wang, Peng; Liu, Donghui; Shen, Zhigang; Liu, Hui; Jia, Zhixin; Zhou, Zhiqiang

    2014-01-01

    The pharmacokinetic and distribution of the enantiomers of quizalofop-ethyl and its metabolite quizalofop-acid were studied in Sprague-Dawley male rats. The two pairs of enantiomers were determined using a validated chiral high-performance liquid chromatography method. Animals were administered quizalofop-ethyl at 10 mg kg−1 orally and intravenously. It was found high concentration of quizalofop-acid in the blood and tissues by both intragastric and intravenous administration, and quizalofop-ethyl could not be detected through the whole study which indicated a quick metabolism of quizalofop-ethyl to quizalofop-acid in vivo. In almost all the samples, the concentrations of (+)-quizalofop-acid exceeded those of (−)-quizalofop-acid. Quizalofop-acid could still be detected in the samples even at 120 h except in brain due to the function of blood-brain barrier. Based on a rough calculation, about 8.77% and 2.16% of quizalofop-acid were excreted through urine and feces after intragastric administration. The oral bioavailability of (+)-quizalofop-acid and (−)-quizalofop-acid were 72.8% and 83.6%. PMID:24964043

  20. Synthesis and degradation behavior of poly(ethyl cyanoacrylate)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poly(ethyl cyanoacrylate) was synthesized using N, N'-dimethyl-p-toulidine (DMPT) as an initiator through anionic/zwitterionic pathway. The degradability and the degradation mechanism of the prepared polymers were carefully examined from various points of views. It was found that the polymers were...

  1. Macroporous hydrogels based on 2-hydroxyethyl methacrylate. Part 4: growth of rat bone marrow stromal cells in three-dimensional hydrogels with positive and negative surface charges and in polyelectrolyte complexes.

    PubMed

    Lesný, P; Prádný, M; Jendelová, P; Michálek, J; Vacík, J; Syková, E

    2006-09-01

    The growth of bone marrow stromal cells was assessed in vitro in macroporous hydrogels based on 2-hydro- xyethyl methacrylate (HEMA) copolymers with different electric charges. Copolymers of HEMA with sodium methacrylate (MA(-)) carried a negative electric charge, copolymers of HEMA with [2-(methacryloyloxy)ethyl] trimethylammonium chloride (MOETA(-)) carried a positive electric charge and terpolymers of HEMA, MA(-) and MOETA(+) carried both, positive and negative electric charges. The charges in the polyelectrolyte complexes were shielded by counter-ions. The hydrogels had similar porosities, based on a comparison of their diffusion parameters for small cations as measured by the real-time tetramethylammonium iontophoretic method of diffusion analysis. The cell growth was studied in the peripheral and central regions of the hydrogels at 2 hours and 2, 7, 14 and 28 days after cell seeding. Image analysis revealed the highest cellular density in the HEMA-MOETA(+) copolymers; most of the cells were present in the peripheral region of the hydrogels. A lower density of cells but no difference between the peripheral and central regions was observed in the HEMA-MA(-) copolymers and in polyelectrolyte complexes. This study showed that positively charged functional groups promote the adhesion of cells. PMID:16932865

  2. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  3. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  4. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including...

  5. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combined residues of the herbicide fenoxaprop-ethyl phenoxy]propanoate] and its metabolites (6-chloro-2... tolerances are established for combined residues of the herbicide fenoxaprop-ethyl, phenoxy]propanoic...

  6. Synthesis of three different galactose-based methacrylate monomers for the production of sugar-based polymers.

    PubMed

    Desport, Jessica S; Mantione, Daniele; Moreno, Mónica; Sardón, Haritz; Barandiaran, María J; Mecerreyes, David

    2016-09-01

    Glycopolymers, synthetic sugar-containing macromolecules, are attracting ever-increasing interest from the chemistry community. Glycidyl methacrylate (GMA) is an important building block for the synthesis of sugar based methacrylate monomers and polymers. Normally, glycidyl methacrylate shows some advantages such as reactivity against nucleophiles or milder synthetic conditions such as other reactive methacrylate monomers. However, condensation reactions of glycidyl methacrylate with for instance protected galactose monomer leads to a mixture of two products due to a strong competition between the two possible pathways: epoxide ring opening or transesterification. In this paper, we propose two alternative routes to synthesize regiospecific galactose-based methacrylate monomers using the epoxy-ring opening reaction. In the first alternative route, the protected galactose is first oxidized to the acid in order to make it more reactive against the epoxide of GMA. In the second route, the protected sugar was first treated with epichlorohydrin followed by the epoxy ring opening reaction with methacrylic acid, to create an identical analogue of the ring-opening product of GMA. These two monomers were polymerized using conventional radical polymerization and were compared to the previously known galactose-methacrylate one. The new polymers show similar thermal stability but lower glass transition temperature (Tg) with respect to the known galactose methacrylate polymer. PMID:27394038

  7. Can quaternary ammonium methacrylates inhibit matrix MMPs and cathepsins?

    PubMed Central

    Tezvergil-Mutluay, Arzu; Agee, Kelli A.; Mazzoni, Annalisa; Carvalho, Ricardo M.; Carrilho, Marcela; Tersariol, Ivarne L.; Nascimento, Fabio D.; Imazato, Satoshi; Tjäderhane, Leo; Breschi, Lorenzo; Tay, Franklin R; Pashley, David H.

    2014-01-01

    Objective Dentin matrices release ICTP and CTX fragments during collagen degradation. ICTP fragments are known to be produced by MMPs. CTX fragments are thought to come from cathepsin K activity. The purpose of this study was to determine if quaternary methacrylates (QAMs) can inhibit matrix MMPs and cathepsins. Methods Dentin beams were demineralizated, and dried to constant weight. Beams were incubated with rh-cathepsin B, K, L or S for 24 h at pH 7.4 to identify which cathepsins release CTX at neutral pH. Beams were dipped in ATA, an antimicrobial QAM to determine if it can inhibit dentin matrix proteases. Other beams were dipped in another QAM (MDPB) to determine if it produced similar inhibition of dentin proteases. Results Only beams incubated with cathepsin K lost more dry mass than the controls and released CTX. Dentin beams dipped in ATA and incubated for 1 week at pH 7.4, showed a concentration-dependent reduction in weight-loss. There was no change in ICTP release from control values, meaning that ATA did not inhibit MMPs. Media concentrations of CTX fell significantly at 15 wt% ATA indicating that ATA inhibits capthesins. Beams dipped in increasing concentrations of MDPB lost progressively less mass, showing that MDPB is a protease-inhibitor. ICTP released from controls or beams exposed to low concentrations were the same, while 5 or 10% MDPB significantly lowered ICTP production. CTX levels were strongly inhibited by 2.5–10% MDPB, indicating that MDPB is a potent inhibitor of both MMPs and cathepsin K. Significance CTX seems to be released from dentin matrix only by cathepsin K. MMPs and cathepsin K and B may all contribute to matrix degradation. PMID:25467953

  8. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  9. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  10. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  11. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  12. 40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or on the...-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its... established for residues of the herbicide fenoxaprop-ethyl, including its metabolites and degradates, in or...

  13. 40 CFR 180.570 - Isoxadifen-ethyl; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of isoxadifen-ethyl (ethyl 5,5-diphenyl-2-isoxazoline-3-carboxylate, (CAS No. 163520-33-0), and...-isoxazolecarboxylic acid, 4,5-dihydro-5,5-diphenyl-, ethyl ester (CAS No. 164520-33-0)), and its metabolites...

  14. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Ethyl silicate, reaction products...

  15. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethyl silicate, reaction products...

  16. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Ethyl silicate, reaction products...

  17. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Ethyl silicate, reaction products...

  18. 40 CFR 721.9514 - Ethyl silicate, reaction products with modified alkoxysilane salt (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Significant New Uses for Specific Chemical Substances § 721.9514 Ethyl silicate, reaction products with.... (1) The chemical substance identified generically as Ethyl silicate, reaction products with modified... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethyl silicate, reaction products...

  19. 40 CFR 721.4250 - Hexanoic acid, 2-ethyl-, ethenyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, ethenyl ester... Substances § 721.4250 Hexanoic acid, 2-ethyl-, ethenyl ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as hexanoic acid, 2-ethyl-, ethenyl ester...

  20. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  1. 40 CFR 721.7290 - Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...)-, ethyl ester. 721.7290 Section 721.7290 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.7290 Propanoic acid, 2-(trimethoxysilyl)-, ethyl ester. (a) Chemical... acid, 2-(trimethoxysilyl)-, ethyl ester (PMN P-01-22; CAS No. 137787-41-8) is subject to...

  2. 40 CFR 180.662 - Trinexapac-ethyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Trinexapac-ethyl; tolerances for... § 180.662 Trinexapac-ethyl; tolerances for residues. (a) General. Tolerances are established for residues of the plant growth inhibitor, trinexapac-ethyl, including its metabolites and degradates, in...

  3. Mechanical Properties of Surface-Charged Poly(Methyl Methacrylate) as Denture Resins

    PubMed Central

    Park, Sang E.; Chao, Maggie; Raj, P. A.

    2009-01-01

    The aim of this study was to examine the mechanical properties of a new surface-modified denture resin for its suitability as denture base material. This experimental resin is made by copolymerization of methacrylic acid (MA) to poly(methyl methacrylate) (PMMA) to produce a negative charge. Four experimental groups consisted of Orthodontic Dental Resin (DENTSPLY Caulk) as a control and three groups of modified PMMA (mPMMA) produced at differing ratios of methacrylic acid (5 : 95, 10 : 90, and 20 : 80 MA : MMA). A 3-point flexural test using the Instron Universal Testing Machine (Instron Corp.) measured force-deflection curves and a complete stress versus strain history to calculate the transverse strength, transverse deflection, flexural strength, and modulus of elasticity. Analysis of Variance and Scheffe Post-test were performed on the data. Resins with increased methacrylic acid content exhibited lower strength values for the measured physical properties. The most significant decrease occurred as the methacrylic acid content was increased to 20% mPMMA. No significant differences at P < .05 were found in all parameters tested between the Control and 5% mPMMA. PMID:20339462

  4. Conversion of (Meth)acrylic acids to methane granular sludge: Initiation by specific anerobic microflora

    SciTech Connect

    Shtarkman, N.B.; Obraztova, A.Y.; Laurinavichyus, K.S.; Galushko, A.S.; Akimenko, V.K.

    1995-03-01

    The role of a specific anaerobic microflora in the initiation of degradation of (meth)acrylic acids to methane by granular sludge from a UASB reactor was investigated. Associations of anaerobic bacteria isolated from the anaerobic sludge, which was used for a long time for treatment of wastewater from (meth)acrylate production, were able to realize the initial stage of (meth)acrylic acid decomposition, i.e., a conversion of acrylic and methacrylic acids to propionic and isobutyric acids, respectively. When added to granules, these association played a role of an {open_quotes}initiator{close_quotes} of the degradation process, which was then continued by the granular sludge microflora utilizing propionate and isobutyrate. Some characteristics of the granules adapted to propionate or isobutyrate are presented. The rates of propionate and isobutyrate consumption by adapted granules is, respectively, 21 and 53 times higher than the values obtained for nonadapted granules. A combined use of {open_quotes}initiating{close_quotes} bacteria and adapted granules provided degradation of (meth)acrylic acids with a maximum methane yield. The possibility is discussed of employing the granules, which are adapted to short-chain fatty acids, and the {open_quotes}initiating{close_quotes} bacteria, which accomplish the initial steps of the organic material decomposition to lower fatty acids, for the conversion of various chemical compounds to methane. 10 refs., 3 figs., 2 tabs.

  5. Facile Fabrication of Gradient Surface Based on (meth)acrylate Copolymer Films

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Yang, H.; Wen, X.-F.; Cheng, J.; Xiong, J.

    2016-08-01

    This paper describes a simple and economic approach for fabrication of surface wettability gradient on poly(butyl acrylate - methyl methacrylate) [P (BA-MMA)] and poly(butyl acrylate - methyl methacrylate - 2-hydroxyethyl methacrylate) [P (BA-MMA-HEMA)] films. The (meth)acrylate copolymer [including P (BA-MMA) and P (BA-MMA-HEMA)] films are hydrolyzed in an aqueous solution of NaOH and the transformation of surface chemical composition is achieved by hydrolysis in NaOH solution. The gradient wetting properties are generated based on different functional groups on the P (BA-MMA) and P (BA-MMA-HEMA) films. The effects of both the surface chemical and surface topography on wetting of the (meth)acrylate copolymer film are discussed. Surface chemical composition along the materials length is determined by XPS, and surface topography properties of the obtained gradient surfaces are analyzed by FESEM and AFM. Water contact angle system (WCAs) results show that the P (BA-MMA-HEMA) films provide a larger slope of the gradient wetting than P (BA-MMA). Moreover, this work demonstrates that the gradient concentration of chemical composition on the poly(meth) acrylate films is owing to the hydrolysis processes of ester group, and the hydrolysis reactions that have negligible influence on the surface morphology of the poly(meth) acrylate films coated on the glass slide. The gradient wettability surfaces may find broad applications in the field of polymer coating due to the compatibility of (meth) acrylate polymer.

  6. Formulation Optimization of Sustained-Release Ammonio Methacrylate Copolymer Microspheres. Effects of Log P and Concentration of Polar Cosolvents, and Role of the Drug/Copolymer Ratio

    PubMed Central

    Sipos, Péter; Rajkó, Róbert; Pintye-Hódi, Klára; Erős, István; Szabó-Révész, Piroska

    2011-01-01

    The objectives of this work were the formulation optimization of the preparation process parameters and to evaluate spray-dried sustained-release microspheres using ammonio methacrylate copolymer (AMC) as a polymer matrix. The effects of log P and the concentrations of the cosolvents (acetone, methyl ethyl ketone and n-butyl acetate) and different drug/copolymer ratios as independent variables on the physicochemical parameters (the W1/O emulsion viscosity, the microsphere production yield, the average particle size, the encapsulation efficiency) and the cumulative in vitro drug release as dependent variables were studied. The optimization was carried out on the basis of the 33 factorial design study. The optimization process results showed that addition of polar cosolvents proved effective, linear relationships were observed between the independent and the dependent variables. The best conditions were achieved by microspheres prepared by using a low/medium cosolvent log P, cosolvent concentration of 25–50% v/v and a drug/copolymer ratio of 1:16. The microspheres ensured sustained release with Nernst and Baker-Lonsdale release profiles. PMID:24309310

  7. Clinical Sensitivity and Specificity of Meconium Fatty Acid Ethyl Esters, Ethyl Glucuronide, and Ethyl Sulfate for Detecting Maternal Drinking During Pregnancy

    PubMed Central

    Himes, Sarah K.; Dukes, Kimberly A.; Tripp, Tara; Petersen, Julie M.; Raffo, Cheri; Burd, Larry; Odendaal, Hein; Elliott, Amy J.; Hereld, Dale; Signore, Caroline; Willinger, Marian; Huestis, Marilyn A.

    2015-01-01

    Background We investigated agreement between self-reported prenatal alcohol exposure (PAE) and objective meconium alcohol markers to determine the optimal meconium marker and threshold for identifying PAE. Methods Meconium fatty acid ethyl esters (FAEE), ethyl glucuronide (EtG), and ethyl sulfate (EtS) were quantified by liquid chromatography-tandem mass spectrometry in 0.1 g meconium from infants of Safe Passage Study participants. Detailed PAE information was collected from women with a validated timeline follow-back interview. As meconium formation begins during weeks 12-20, maternal self-reported drinking at or beyond 19 weeks was our exposure variable. Results Of 107 women, 33 reported no alcohol consumption in pregnancy, 16 stopped drinking by week 19, and 58 drank beyond 19 weeks (including 45 3rd trimester drinkers). There was moderate-substantial agreement between self-reported PAE ≥19 weeks and meconium EtG ≥30 ng/g (kappa: 0.57, 95% CI 0.41-0.73). This biomarker and associated cutoff was superior to a 7 FAEE sum ≥2 nmol/g and all other individual and combination marker cutoffs. With meconium EtG ≥30 ng/g as the gold-standard condition and maternal self-report ≥19 weeks gestation as the test condition, 82% sensitivity (95% CI: 71.6-92.0) and 75% specificity (95% CI: 63.2-86.8) were observed. A significant dose-concentration relationship between self-reported drinks per drinking day and meconium EtG ≥30 ng/g also was observed (P<0.01). Conclusions We assessed meconium EtG, EtS, and FAEE concentrations in the same meconium sample and compared concentrations to detailed self-reported PAE data. Maternal alcohol consumption ≥19 weeks was better represented by meconium EtG ≥30 ng/g compared to current FAEE cutoffs. PMID:25595440

  8. Optical on-line method of ethyl mercaptan detection in liquid phase in motor fuels

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-11-01

    The letter reports on the experimental research of the absorption spectra of ethyl mercaptan in liquid phase in various motor fuels (petrol, kerosene, and diesel fuel). The values of ethyl mercaptan absorption sections were obtained in the above-mentioned fuels in the spectral range of 280-475 nm, and the dependences of ethyl mercaptan absorption coefficients on its part in the analyzed mixture with motor fuels were researched. On the basis of the obtained results we propose an optical on-line method of ethyl mercaptan detection in motor fuels. The optimal spectral ranges for the highest sensitivity of ethyl mercaptan detection in various motor fuels were determined.

  9. Toughening epoxy resin with poly(methyl methacrylate)-grafted natural rubber

    SciTech Connect

    Rezaifard, A.H.; Hodd, K.A.; Barton, J.M.

    1993-12-31

    A novel rubber, poly(methyl methacrylate)-g-natural rubber (Hevea-plus MG), has been studied as a toughening agent for bisphenol A diglycidyl ether (Shell 828 epoxy resin) cured with piperidine. Effective dispersions of the rubber, in concentrations of 2-10 parts per hundred parts resin, were achieved by adjusting the solubility parameter of the epoxy to approximate that of poly(methyl methacrylate) by adding bisphenol A. The fracture energy of the rubber-modified resin was determined by compact tension tests (in the temperature range -60 to +40{degrees}C) and by Charpy impact tests. The poly(methyl methacrylate)-g-natural rubber was found to be an effective toughening agent for the epoxy resin at both low and high rates of strain. Possible fracture mechanisms are discussed. 22 refs., 16 figs., 5 tabs.

  10. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    PubMed Central

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

  11. Chondrocyte Generation of Cartilage-Like Tissue Following Photoencapsulation in Methacrylated Polysaccharide Solution Blends.

    PubMed

    Hayami, James W S; Waldman, Stephen D; Amsden, Brian G

    2016-07-01

    Chondrocyte-seeded, photo-cross-linked hydrogels prepared from solutions containing 50% mass fractions of methacrylated glycol chitosan or methacrylated hyaluronic acid (MHA) with methacrylated chondroitin sulfate (MCS) are cultured in vitro under static conditions over 35 d to assess their suitability for load-bearing soft tissue repair. The photo-cross-linked hydrogels have initial equilibrium moduli between 100 and 300 kPa, but only the MHAMCS hydrogels retain an approximately constant modulus (264 ± 5 kPa) throughout the culture period. Visually, the seeded chondrocytes in the MHAMCS hydrogels are well distributed with an apparent constant viability in culture. Multicellular aggregates are surrounded by cartilaginous matrix, which contain aggrecan and collagen II. Thus, co-cross-linked MCS and MHA hydrogels may be suited for use in an articular cartilage or nucleus pulposus repair applications. PMID:27061241

  12. Designing ultraviolet curing of multifunctional (meth)acrylate hard coats

    NASA Astrophysics Data System (ADS)

    Wen, Mei

    Ultraviolet (UV) curing rapidly converts multifunctional (meth)acrylate liquid monomers into highly cross-linked, impervious, hard polymeric coatings at ambient temperature. This solidification process occurs by free-radical cross-linking polymerization. To achieve a better design of this process, it is desirable to have high conversion of functional groups, low stress, adequate mechanical properties, and low costs. To approach this design goal, the following modeling and experimental work was carried out. Firstly, a kinetic model was developed to simulate radical trapping. This model predicts a peak in the concentration of active radicals and a monotonic rise of the concentration of trapped radicals during polymerization. It also predicts a decrease in the fraction of trapped radicals at a given conversion as the UV light intensity is raised. Secondly, a kinetic gelation model, in which reaction occurs locally on a lattice, was developed. Unlike previous such models, this model accounts for free radical reaction time more accurately. It was found that a more uniform distribution of reacted sites leads to a favored propagation at a given conversion. Moreover, radical trapping and termination were found to shorten the kinetic chain length and to lower the asymptotic conversion reached when initiators are exhausted. Thirdly, elastic modulus evolution was simulated with a rigidity percolation model, in which bonds created by free-radical polymerization are represented as rigidly jointed beams. Simulations show that modulus of a network depends on the connectivity between monomer units as well as bonding structure. Finally, experimental determination of volume shrinkage of a sandwiched film was measured with a dynamic mechanical analyzer probe. A faster reaction causes more severely delayed volume shrinkage from the thermodynamic equilibrium volume required by the reaction. Nevertheless, volume shrinks more when the shrinkage of the thermodynamic volume rises. In

  13. Reactions of methyl and ethyl radicals with uranium hexafluoride

    NASA Astrophysics Data System (ADS)

    Lyman, John L.; Laguna, Glenn

    1985-01-01

    We have measured the rates of reaction of both methyl and ethyl radicals with uranium hexafluoride (UF6) in the gas phase. The method we used was to photolyze samples of UF6 in the presence of either methane or ethane. The radicals produced by reaction of fluorine atoms with these species then react with either themselves or with UF6. We inferred the rate constants from ratios of the reaction products and the published rate constants for radical recombination. The diagnostic technique was gas chromatography. The resulting rate constants for reaction with UF6 were (1.6±0.8)×10-14 cm3 molecule-1 s-1 for methyl radicals and (4±2)×10-11 cm3 molecule-1 s-1 for ethyl radicals.

  14. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether

    PubMed Central

    Andrews, Ian P.; Kwon, Ohyun

    2008-01-01

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethyl ethynyl ether using 0.1% palladium(0) catalyst and 1.0 equiv of tributyltin hydride. The product obtained is a mixture of regioisomers that can be carried forward with exclusive reaction of the β-isomer. This method is highly reproducible; relative to previously reported procedures, it is more economical and involves a more facile purification procedure. PMID:20011027

  15. Fragrance material review on 2-ethyl-1-hexanol.

    PubMed

    McGinty, D; Scognamiglio, J; Letizia, C S; Api, A M

    2010-07-01

    A summary of the safety data available for 2-ethyl-1-hexanol when used as a fragrance ingredient is presented. 2-Ethyl-1-hexanol is a member of the fragrance structural group branched chain saturated alcohols in which the common characteristic structural element is one hydroxyl group per molecule, and a C(4) to C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659633

  16. Fragrance material review on 2-ethyl-1-butanol.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2010-07-01

    A toxicologic and dermatologic review of 2-ethyl-1-butanol when used as a fragrance ingredient is presented. 2-Ethyl-1-butanol is a member of the fragrance structural group branched chain saturated alcohols. The common characteristic structural elements of the alcohols with saturated branched chain are one hydroxyl group per molecule, and a C(4)-C(12) carbon chain with one or several methyl side chains. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. A safety assessment of the entire branched chain saturated alcohol group will be published simultaneously with this document; please refer to Belsito et al. (2010) for an overall assessment of the safe use of this material and all other branched chain saturated alcohols in fragrances. PMID:20659644

  17. Turbulent Motion in Ethyl Acetate-Water System

    NASA Astrophysics Data System (ADS)

    Ahmad, Jamil

    2000-09-01

    An overhead projector demonstration is described in which 4 mL of ethyl acetate is added to 10 mL of water contained in a 10-cm diameter Petri dish. Within a minute or so of the addition, image of a turbulent motion appears on the screen, at first at a few centers that eventually organize themselves in a line. The image of the line of turbulence is quite striking and resembles a moving front of dancing flames. The phenomenon arises because as ethyl acetate evaporates from the region where it has spread in the form of a monolayer, fresh material gets transferred to take its place. Because of the viscosity effects, this transfer of the surface film causes movement in the bulk of the material as well, making the process visible.

  18. Enantioselective hydrolysis of naproxen ethyl ester catalyzed by monoclonal antibodies.

    PubMed

    Shi, Zhen-Dan; Yang, Bing-Hui; Zhao, Jing-Jing; Wu, Yu-Lin; Ji, Yong-Yong; Yeh, Ming

    2002-07-01

    This report described that a hapten of racemic phosphonate 3 designed as the mimic of the transition state of hydrolysis of naproxen ethyl ester was successfully synthesized from easily available 2-acetyl-6-methoxy-naphthalene 5. Then BALB/C mice were immunized and one of the monoclonal catalytic antibodies, N116-27, which enantioselectively accelerated the hydrolysis of the R-(-)-naproxen ethyl ester was given. The Michaelis-Menton parameter for the catalyzed reaction was K(M)=6.67 mM and k(cat)/k(uncat)=5.8 x 10(4). This enantioselective result was explained by the fact that the R-isomer of rac-hapten was more immunogenic than the S-isomer. PMID:11983513

  19. SPECTROSCOPIC CHARACTERIZATION AND DETECTION OF ETHYL MERCAPTAN IN ORION

    SciTech Connect

    Kolesniková, L.; Alonso, J. L.; Daly, A. M.; Tercero, B.; Cernicharo, J.; Gordon, B. P.; Shipman, S. T. E-mail: jlalonso@qf.uva.es E-mail: terceromb@cab.inta-csic.es E-mail: brittany.gordon@ncf.edu

    2014-03-20

    New laboratory data of ethyl mercaptan, CH{sub 3}CH{sub 2}SH, in the millimeter- and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of gauche-CH{sub 3}CH{sub 2}SH toward Orion KL. This identification is supported by 77 unblended or slightly blended lines plus no missing transitions in the range 80-280 GHz. A detection of methyl mercaptan, CH{sub 3}SH, in the spectral survey of Orion KL is reported as well. Our column density results indicate that methyl mercaptan is ≅ 5 times more abundant than ethyl mercaptan in the hot core of Orion KL.

  20. A Facile Strategy for Catalyst Separation and Recycling Suitable for ATRP of Hydrophilic Monomers Using a Macroligand.

    PubMed

    Jiang, Xiaowu; Wu, Jian; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2016-01-01

    How to simply and efficiently separate and recycle catalyst has still been a constraint for the wide application of atom transfer radical polymerization (ATRP), especially for the polymerization systems with hydrophilic monomers because the polar functional groups may coordinate with transition metal salts, resulting in abundant catalyst residual in the resultant water-soluble polymers. In order to overcome this problem, a latent-biphasic system is developed, which can be successfully used for ATRP catalyst separation and recycling in situ for various kinds of hydrophilic monomers for the first time, such as poly(ethylene glycol) monomethyl ether methacrylate (PEGMA), 2-hydroxyethyl methacrylate (HEMA), 2-(dimethylamino)ethyl methacrylate (DMAEMA), N,N-dimethyl acrylamide (DMA), and N-isopropylacrylamide (NIPAM). Herein, random copolymer of octadecyl acrylate (OA), MA-Ln (2-(bis(pyridin-2-ylmethyl)amino)ethyl acrylate), and POA-ran-P(MA-Ln) is designed as the macroligand, and heptane/ethanol is selected as the biphasic solvent. Copper(II) bromide (CuBr2 ) is employed as the catalyst, PEG-bound 2-bromo-2-methylpropanoate (PEG350 -Br) as the water-soluble ATRP initiator and 2,2'-azobis(isobutyronitrile) (AIBN) as the azo-initiator to establish an ICAR (initiators for continuous activator regeneration) ATRP system. Importantly, well-defined water-soluble polymers are obtained even though the recyclable catalyst is used for sixth times. PMID:26506506

  1. Mutagenicity assessment of acrylate and methacrylate compounds and implications for regulatory toxicology requirements.

    PubMed

    Johannsen, F R; Vogt, Barbara; Waite, Maureen; Deskin, Randy

    2008-04-01

    Esters of acrylic acid and methacrylic acid, more commonly known as acrylates and methacrylates, respectively, are key raw materials in the coatings and printing industry, with several of its chemical class used in food packaging. The results of over 200 short-term in vitro and in vivo mutagenicity studies available in the open literature have been evaluated. Despite differences in acrylate or methacrylate functionality or in the number of functional groups, a consistent pattern of test response was seen in a typical regulatory battery of mutagenicity tests. No evidence of point mutations was observed when acrylic acid or over 60 acrylates and methacrylates were investigated in Salmonella bacterial tests or in hprt mutation tests mammalian cells, and no evidence of a mutagenic effect was seen when tested in whole animal clastogenicity and/or aneuploidy (chromosomal aberration/micronucleus) studies. Consistent with the in vivo testing results, acrylic acid exhibited no evidence of carcinogenicity in chronic rodent cancer bioassays. In contrast, acrylic acid and the entire acrylate and methacrylate chemical class produced a consistently positive response when tested in the mouse lymphoma assay and/or other in vitro mammalian cell assays designed to detect clastogenicity. The biological relevance of this in vitro response is questioned based on the non-concordance of in vitro results with those of in vivo studies addressing the same mutagenic endpoint (clastogenicity). Thus, in short-term mutagenicity tests, the acrylates and methacrylates behave as a single chemical category, and genotoxicity behavior of a similar chemical can be predicted with confidence by inclusion within this chemical class, thus avoiding unnecessary testing. PMID:18346829

  2. [Detection and application of ethyl glucuronide in forensic toxicology].

    PubMed

    Zhao, Hui; Zhuo, Xian-yi; Shen, Bao-hua

    2009-02-01

    Ethyl glucuronide is a specific metabolite of ethanol. There have been plenty of articles referring its pharmacokinetics, detection and application as a specific bio-marker of alcohol intake. This article reviews various analytical methods of EtG, relationship between EtG quantification and ethanol intake, and criteria for determining chronic alcohol abuse, and origin of ethanol found in the cadavers by EtG analysis. EtG has its potential application in forensic toxicology. PMID:19397218

  3. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number of methyl groups and y is the number of ethyl groups. The average value of x is 0.3 and the average... the dry sample. (2) The viscosity of an aqueous solution, 2.5 grams of the material in 100...

  4. 21 CFR 172.872 - Methyl ethyl cellulose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... a cellulose ether having the general formula [C6H(10 -x-y)O5(CH3)x(C2H5)y]n, where x is the number of methyl groups and y is the number of ethyl groups. The average value of x is 0.3 and the average... the dry sample. (2) The viscosity of an aqueous solution, 2.5 grams of the material in 100...

  5. Physiologically based pharmacokinetic modeling of ethyl acetate and ethanol in rodents and humans.

    PubMed

    Crowell, S R; Smith, J N; Creim, J A; Faber, W; Teeguarden, J G

    2015-10-01

    A physiologically based pharmacokinetic (PBPK) model was developed and applied to a metabolic series approach for the ethyl series (i.e., ethyl acetate, ethanol, acetaldehyde, and acetate). This approach bases toxicity information on dosimetry analyses for metabolically linked compounds using pharmacokinetic data for each compound and toxicity data for parent or individual compounds. In vivo pharmacokinetic studies of ethyl acetate and ethanol were conducted in rats following IV and inhalation exposure. Regardless of route, ethyl acetate was rapidly converted to ethanol. Blood concentrations of ethyl acetate and ethanol following both IV bolus and infusion suggested linear kinetics across blood concentrations from 0.1 to 10 mM ethyl acetate and 0.01-0.8 mM ethanol. Metabolic parameters were optimized and evaluated based on available pharmacokinetic data. The respiratory bioavailability of ethyl acetate and ethanol were estimated from closed chamber inhalation studies and measured ventilation rates. The resulting ethyl series model successfully reproduces blood ethyl acetate and ethanol kinetics following IV administration and inhalation exposure in rats, and blood ethanol kinetics following inhalation exposure to ethanol in humans. The extrapolated human model was used to derive human equivalent concentrations for the occupational setting of 257-2120 ppm ethyl acetate and 72-517 ppm ethyl acetate for continuous exposure, corresponding to rat LOAELs of 350 and 1500 ppm. PMID:26297692

  6. Impact of Association Colloids on Lipid Oxidation in Triacylglycerols and Fatty Acid Ethyl Esters.

    PubMed

    Homma, Rika; Suzuki, Karin; Cui, Leqi; McClements, David Julian; Decker, Eric A

    2015-11-25

    The impact of association colloids on lipid oxidation in triacylglycerols and fatty acid ethyl esters was investigated. Association colloids did not affect lipid oxidation of high oleic safflower and high linoleic safflower triacylglycerols, but were prooxidative in fish triacylglycerols. Association colloids retarded aldehyde formation in stripped ethyl oleate, linoleate, and fish oil ethyl esters. Interfacial tension revealed that lipid hydroperoxides were surface active in the presence of the surfactants found in association colloids. The lipid hydroperoxides from ethyl esters were less surface active than triacylglycerol hydroperoxides. Stripping decreased iron and copper concentrations in all oils, but more so in fatty acid ethyl esters. The combination of lower hydroperoxide surface activity and low metal concentrations could explain why association colloids inhibited lipid oxidation in fatty acid ethyl esters. This research suggests that association colloids could be used as an antioxidant technology in fatty acid ethyl esters. PMID:26506263

  7. Sensory reception of the primer pheromone ethyl oleate

    NASA Astrophysics Data System (ADS)

    Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

    2012-05-01

    Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

  8. Fragrance material review on ethyl phenyl carbinyl acetate.

    PubMed

    McGinty, D; Letizia, C S; Api, A M

    2012-09-01

    A toxicologic and dermatologic review of ethyl phenyl carbinyl acetate when used as a fragrance ingredient is presented. Ethyl phenyl carbinyl acetate is a member of the fragrance structural group Aryl Alkyl Alcohol Simple Acid Esters (AAASAE). The AAASAE fragrance ingredients are prepared by reacting an aryl alkyl alcohol with a simple carboxylic acid (a chain of 1-4 carbons) to generate formate, acetate, propionate, butyrate, isobutyrate and carbonate esters. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for ethyl phenyl carbinyl acetate were evaluated, then summarized, and includes: physical properties; acute toxicity; skin irritation; and skin sensitization data. A safety assessment of the entire AAASAE will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all AAASAE in fragrances. PMID:22433983

  9. Synthesis and characterization of carbon fibers functionalized with poly (glycidyl methacrylate) via atom transfer radical polymerization

    NASA Astrophysics Data System (ADS)

    Wu, Yongwei; Xiong, Lei; Qin, Xiaokang; Wang, Zhengyue; Ding, Bei; Ren, Huan; Pi, Xiaolong

    2015-07-01

    In this work, polyacrylonitrile (PAN)-based carbon fibers (CF) were chemically modified with poly (glycidyl methacrylate) (PGMA) via atom transfer radical polymerization (ATRP) to improve the interaction between the CF and polymer matrix. The FT-IR, TGA, and XPS were used to determine the chemical structure of the resulting products and the quantities of PGMA chains grafted from the CF surface. The experimental results confirm that the CF surface was functionalized and glycidyl methacrylate was graft-polymerized onto the CF, and the grafting content of polymer could reach 10.2%.

  10. pH-sensitive methacrylic copolymer gels and the production thereof

    DOEpatents

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-05-15

    The present invention provides novel gel forming methacrylic blocking copolymers that exhibit cationic pH-sensitive behavior as well as good water solubility. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol)methyl ether polymer. The polymers may be used for drug and gene delivery, protein separation, as structural supplements, and more.

  11. Synthesis and physicochemical properties of organofluorine esters of acrylic, methacrylic, and maleic acids

    SciTech Connect

    Gol'din, G.S.; Averbakh, K.O.; Lavygin, I.A.; Nekrasova, L.A.

    1985-12-01

    The authors synthesize and study the physicochemical properties of organofluorine acrylates, methacrylates, and maleates. The organofluorine esters are colorless liquids; their composition and structure were confirmed by elemental analysis and IR spectra. The results of studies of the dependence of the density, surface tension, and viscosity of these compounds on temperature are presented. The results revealed the influence of the length of the fluorocarbon chain on the combination of the physicochemical properties of organofluorine acrylates, methacrylates, and maleates, and also provided a method for estimating certain thermophysical characteristics of such compounds without recourse to experimental measurements.

  12. Balancing Size Exclusion and Adsorption of Methacrylate Polymers in Nanoporous Silica

    NASA Astrophysics Data System (ADS)

    Abdulahad, Asem; Lee, Sekyung; Chang, Taihyun; Ryu, Chang

    2010-03-01

    Liquid chromatography at the critical condition (LCCC) is a high performance liquid chromatography (HPLC) technique that lies between size exclusion chromatography (SEC) and adsorption-based interaction chromatography (IC) where the elution of polymers becomes independent of polymer molecular weight. At LCCC, the balance between the entropic exclusion and the enthalpic adsorption interactions between polymers and stationary phases results in the simultaneous elution of polymers regardless of molecular weight. Using C18-bonded silica chromatographic columns we demonstrate the LCCC elution of a series of methacrylate polymers and discuss how the alkyl side groups in methacrylate polymers affects the adsorption of polymer chains against the size exclusion in nanopores.

  13. Effect of filling technique on the bond strength of methacrylate and silorane-based composite restorations.

    PubMed

    Machado, Fernanda Weingartner; Borges, Fernanda Blos; Cenci, Maximiliano Sérgio; Moraes, Rafael Ratto de; Boscato, Noéli

    2016-01-01

    The bond strength of methacrylate (Z350, 3M ESPE) and silorane (P90, 3M ESPE) restorations, using different cavity filling techniques, was investigated. Cavities (6 × 3 × 3) in bovine teeth were filled using bulk, oblique, or horizontal increments. A push-out test was carried out after 24 h. Data were statistically analyzed (α = 5%). Methacrylate-based composites and the horizontal filling technique showed the highest bond strength values (10.2 ± 3.9, p < 0.05). Silorane-based composites showed no statistically significant differences regarding the filling techniques (p > 0.05). PMID:27050940

  14. On the pH Responsive, Charge Selective, Polymer Brush-Mediated Transport Probed by Traditional and Scanning Fluorescence Correlation Spectroscopy

    PubMed Central

    Daniels, C. R.; Tauzin, L. J.; Foster, E.; Advincula, R. C.; Landes, C. F.

    2013-01-01

    The complete and reversible charge-selective sequestration of fluorophores by a weak polyelectrolyte brush, poly(2-(dimethylamino) ethyl-methacrylate) (PDMAEMA) was demonstrated using Fluorescence Correlation Spectroscopy (FCS). The chemistry and thickness of the weak polyelectrolyte PDMAEMA was tuned reversibly between neutral and cationic polymer forms. Thus, by switching the pH successively, the brush architecture was tuned to selectively trap and release anionic dye probes, while continuously excluding cationic molecules. In addition, line-scan FCS was implemented and applied for the first time to a synthetic polymer system, and used to identify a new, slower diffusion time on the order of seconds for the sequestered anionic probe under acidic conditions. These results, which quantify the selective sequestration properties of the PDMAEMA brush, are important because they enable a better understanding of transport in polymers, and establish a spectroscopic means of evaluating materials with proposed applications in separations science, charge storage/release and environmental remediation. PMID:23092304

  15. Antibacterial cellulose fiber via RAFT surface graft polymerization.

    PubMed

    Roy, Debashish; Knapp, Jeremy S; Guthrie, James T; Perrier, Sébastien

    2008-01-01

    2-(dimethylamino)ethyl methacrylate (DMAEMA) was polymerized from cellulosic filter paper via reversible addition-fragmentation chain transfer (RAFT) polymerization. The tertiary amino groups of the grafted PDMAEMA chains were subsequently quaternized with alkyl bromides of different chain lengths (C8-C16) to provide a large concentration of quaternary ammonium groups on the cellulose surface. The antibacterial activity of the quaternized and nonquaternized PDMAEMA-grafted cellulosic fibers was tested against Escherichia coli. The antibacterial activity was found to depend on the alkyl chain length and on the degree of quaternization, i.e., the amount of quaternary amino groups present in the cellulose graft copolymers. The PDMAEMA-grafted cellulose fiber with the highest degree of quaternization and quaternized with the shortest alkyl chains was found to exhibit particularly high activity against E. coli. PMID:18067264

  16. Biocompatible zwitterionic sulfobetaine copolymer-coated mesoporous silica nanoparticles for temperature-responsive drug release.

    PubMed

    Sun, Jiao-Tong; Yu, Zhi-Qiang; Hong, Chun-Yan; Pan, Cai-Yuan

    2012-05-14

    A novel nanocontainer, which could regulate the release of payloads, has been successfully fabricated by attaching zwitterionic sulfobetaine copolymer onto the mesoporous silica nanoparticles (MSNs). RAFT polymerization is employed to prepare the hybrid poly(2-(dimethylamino)ethyl methacrylate)-coated MSNs (MSN-PDMAEMA). Subsequently, the tertiary amine groups in PDMAEMA are quaternized with 1,3-propanesultone to get poly(DMAEMA-co-3-dimethyl(methacryloyloxyethyl)ammonium propanesulfonate)-coated MSNs [MSN-Poly(DMAEMA-co-DMAPS)]. The zwitterionic PDMAPS component endows the nanocarrier with biocompatibility, and the PDMAEMA component makes the copolymer shell temperature-responsive. Controlled release of loaded rhodamine B has been achieved in the saline solutions. PMID:22488562

  17. Thermoresponsive hydrogels in biomedical applications: A seven-year update.

    PubMed

    Klouda, Leda

    2015-11-01

    Thermally responsive hydrogels modulate their gelation behavior upon temperature change. Aqueous solutions solidify into hydrogels when a critical temperature is reached. In biomedical applications, the change from ambient temperature to physiological temperature can be employed. Their potential as in situ forming biomaterials has rendered these hydrogels very attractive. Advances in drug delivery, tissue engineering and cell sheet engineering have been made in recent years with the use of thermoresponsive hydrogels. The scope of this article is to review the literature on thermosensitive hydrogels published over the past seven years. The article concentrates on natural polymers as well as synthetic polymers, including systems based on N-isopropylacrylamide (NIPAAm), poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO), poly(ethylene glycol) (PEG)-biodegradable polyester copolymers, poly(organophosphazenes) and 2-(dimethylamino) ethyl methacrylate (DMAEMA). PMID:26614556

  18. Synthesis, characterization, and controllable drug release of pH-sensitive hybrid magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhou, Lilin; Yuan, Jinying; Yuan, Weizhong; Sui, Xiaofeng; Wu, Sizhu; Li, Zhaolong; Shen, Dezhong

    2009-09-01

    The synthesis of magnetite nanoparticles coated with pH-sensitive poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA) via atom transfer radical polymerization (ATRP) for use as novel potential carriers for targeted drug delivery and controllable release is reported. The organic/inorganic hybrid nanoparticles were obtained with a narrow molecular weight distribution. The pH-sensitivity of the nanoparticles was investigated by the measurement of the pH dependence of hydrodynamic radius and the superparamagnetism was illustrated by vibrating sample magnetometer (VSM). The behavior of model drug phenolphthalein released from the nanoparticles indicated that the rate of drug release could be effectively controlled by altering the pH values of the environment.

  19. One-Step Immobilization of Initiators for Surface-Initiated Ring Opening Polymerization and Atom Transfer Radical Polymerization by Poly(norepinephrine) Coating.

    PubMed

    Kang, Sung Min; Lee, Haeshin

    2015-02-01

    We report a facile method for surface-initiated ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP) via a poly(norepinephrine) coating. Solid substrates were modified by poly(norepinephrine) under alkaline conditions, with concurrent co-adsorption of an ATRP initiator. The poly(norepinephrine) layer acted as a ROP initiator due to the presence of hydroxyl groups in its side chain, resulting in a surface that was able to initiate ATRP and ROP simultaneously. ε-Caprolactone (ε-CL) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) were grafted onto the surface via ROP and ATRP, respectively, and the polymers subsequently grown from the surfaces were characterized in detail using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle goniometry, and atomic force microscopy (AFM). PMID:26353697

  20. pH-responsive PDMS-b-PDMAEMA micelles for intracellular anticancer drug delivery.

    PubMed

    Car, Anja; Baumann, Patric; Duskey, Jason T; Chami, Mohamed; Bruns, Nico; Meier, Wolfgang

    2014-09-01

    A series of poly(dimethysiloxane)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMS-b-PDMAEMA) block copolymers were synthesized with atom transfer radical polymerization (ATRP). In aqueous solution the polymers self-assembled into micelles with diameters between 80 and 300 nm, with the ability to encapsulate DOX. The polymer with the shortest PDMAEMA block (5 units) displayed excellent cell viability, while micelles containing longer PDMAEMA block lengths (13 and 22 units) led to increased cytotoxicity. The carriers released DOX in response to a decrease in pH from 7.4 to 5.5. Confocal laser scanning microscopy (CLSM) revealed that nanoparticles were taken up by endocytosis into acidic cell compartments. Furthermore, DOX-loaded nanocarriers exhibited intracellular pH-response as changes in cell morphology and drug release were observed within 24 h. PMID:25068477

  1. Revealing the supramolecular nature of side-chain terpyridine-functionalized polymer networks.

    PubMed

    Brassinne, Jérémy; Jochum, Florian D; Fustin, Charles-André; Gohy, Jean-François

    2015-01-01

    Nowadays, finely controlling the mechanical properties of polymeric materials is possible by incorporating supramolecular motifs into their architecture. In this context, the synthesis of a side-chain terpyridine-functionalized poly(2-(dimethylamino)ethyl methacrylate) is reported via reversible addition-fragmentation chain transfer polymerization. By addition of transition metal ions, concentrated aqueous solutions of this polymer turn into metallo-supramolecular hydrogels whose dynamic mechanical properties are investigated by rotational rheometry. Hence, the possibility for the material to relax mechanical constrains via dissociation of transient cross-links is brought into light. In addition, the complex phenomena occurring under large oscillatory shear are interpreted in the context of transient networks. PMID:25569082

  2. Importance of Chain Connectivity in the Formation of Non-covalent Interactions between Polymers and Single-Walled Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Linton, Dias; Miller, Brad C.; Li, Huimin; Feigerle, Charles; Sumpter, Bobby G.; Dadmun, Mark D.

    2009-03-01

    Our work is focused on understanding and utilizing non-covalent electron donor-acceptor (EDA) interactions between polymers and SWNT to optimize interfacial adhesion and homogeneity of nanocomposites without modifying the SWNT native surface. Nanocomposites with polymer bound electron donating 2-(dimethylamino)ethyl methacrylate or electron accepting acrylonitrile and cyanostyrene moieties leads to improved SWNT dispersion if the interacting functional group is a minor component of a copolymer matrix. Correlation of experimental (Raman mapping, Raman D* band peak shifts, and optical microscopy) and computational results indicates that chain connectivity is critical in controlling the accessibility of the functional groups to form EDA interactions. Thus, controlling the amount of e^- donating or withdrawing moieties throughout the polymer chain will direct the extent of EDA interaction, which enables tuning the SWNT dispersion.

  3. Stimuli Response of Cationic Polymer Brush Prepared by ATRP: Application in Peptide Fractionation.

    PubMed

    Scott, Colleen; Mitrovic, Bojan; Eastwood, Stephanie; Kinsel, Gary

    2014-08-01

    Random cationic copolymer brushes composed of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and N-isopropylacrylamide (NIPAAm) were synthesized using the atom transfer radical polymerization (ATRP) method. The effects of varying the monomer feed ratios (30:70 and 70:30 DMAEMA:NIPAAm) and polymerization times on the film height, morphology and stimuli response to pH of the brush were evaluated. While the polymerization time was found to have little influence on the properties of the brushes, the monomer feed ratios had a great impact. The 70 % DMAEMA polymer brush had similar height as the 30 % DMAEMA brush after 45 min; however, it had a greater response to pH and morphological change compared to the 30 % DMAEMA. The 70 % DMAEMA brush was used to demonstrate an efficient approach to alleviate the ion suppression effect in MALDI analysis of complex mixtures by effectively fractionating a binary mixture of peptides prior to MALDI-MS analysis. PMID:25253913

  4. In situ spectroscopic ellipsometry of pH-responsive polymer brushes on gold substrates.

    PubMed

    Rauch, Sebastian; Uhlmann, Petra; Eichhorn, Klaus-Jochen

    2013-11-01

    The dynamic and reversible switching behaviour of polyelectrolyte brushes of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) toward changes of the pH value was studied by in situ VIS-spectroscopic ellipsometry (SE). For this, PDMAEMA brushes with three different molecular weights were synthesized via the "grafting from" method using surface initiated atom transfer radical polymerization. In detail, the applicability of different SE data modelling to describe the optical properties of the different brush layers in the swollen and collapsed state was investigated. Especially for the PDMAEMA brushes with a high molecular weight, an improved optical modelling of the experimental data could be achieved and revealed an exponential distribution of the PDMAEMA fraction in the brush layer. PMID:23812852

  5. Origin of Lateral Nanoscale Heterogeneities in Weak Polyelectrolyte Brushes

    NASA Astrophysics Data System (ADS)

    Won, You-Yeon; Witte, Kevin; Hur, Jaehyun

    2009-03-01

    In this talk, we will first discuss experimental evidence of lateral nanoscale heterogeneities in a single-component weak polyelectrolyte brush system under zero to low salt conditions. Using an amphiphilic diblock copolymer, poly(2-(dimethylamino)ethyl methacrylate-b-n-butyl acrylate) (PDMAEMA-PnBA), for Langmuir film compression and Langmuir-Blodgett deposition on a hydrophobic substrate followed by fluid AFM imaging, we show the existence of regions of different brush heights, indicative of the thermodynamic instability (and resultant local clustering) of the PDMAEMA chains in the low-salt limit. Using SCF and scaling theories, we will also show that the lateral heterogeneities occur due to the combined effects of (i) the osmotic instability regulated by charge equilibrium and (ii) the hydrophobicity of the chains.

  6. Polysulfobetaine films prepared by electrografting technique for reduction of biofouling on electroconductive surfaces

    NASA Astrophysics Data System (ADS)

    Stach, Marek; Kroneková, Zuzana; Kasák, Peter; Kollár, Jozef; Pentrák, Martin; Mičušík, Matej; Chorvát, Dušan; Nunney, Tim S.; Lacík, Igor

    2011-10-01

    The sulfobetaine films were prepared on stainless steel and golden surfaces. In the first step, the poly(2-(dimethylamino)ethyl methacrylate) film was created by employing the electrografting polymerization technique. In the second step, this film was modified to polysulfobetaine, i.e. the polymer film bearing the zwitterionic groups. The presence of the electrografted film and its modification were determined by contact angle measurements, infrared spectroscopy in reflectance mode and X-ray photoelectron spectroscopy. The prepared films were homogeneous with the thickness from about 5 to 26 nm as determined by X-ray photoelectron spectroscopy. The atomic force microscopy measurements showed the increase of surface roughness upon the surface coating. In vitro tests using adherent RAT-2 fibroblast cells and fluorescently labelled bovine serum albumin proteins showed that prepared polysulfobetaine films can be used in applications requiring the resistance against cell attachment and biofouling.

  7. Conductive Nanowires Templated by Molecular Brushes.

    PubMed

    Raguzin, Ivan; Stamm, Manfred; Ionov, Leonid

    2015-10-21

    In this paper, we report the fabrication of conductive nanowires using polymer bottle brushes as templates. In our approach, we synthesized poly(2-dimethylamino)ethyl methacrylate methyl iodide quaternary salt brushes by two-step atom transfer radical polymerization, loaded them with palladium salt, and reduced them in order to form metallic nanowires with average lengths and widths of 300 and 20 nm, respectively. The obtained nanowires were deposited between conductive gold pads and were connected to them by sputtering of additional pads to form an electric circuit. We connected the nanowires in an electric circuit and demonstrated that the conductivity of these nanowires is around 100 S·m(-1). PMID:26418290

  8. Stimuli Response of Cationic Polymer Brush Prepared by ATRP: Application in Peptide Fractionation

    PubMed Central

    Scott, Colleen; Mitrovic, Bojan; Eastwood, Stephanie; Kinsel, Gary

    2014-01-01

    Random cationic copolymer brushes composed of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and N-isopropylacrylamide (NIPAAm) were synthesized using the atom transfer radical polymerization (ATRP) method. The effects of varying the monomer feed ratios (30:70 and 70:30 DMAEMA:NIPAAm) and polymerization times on the film height, morphology and stimuli response to pH of the brush were evaluated. While the polymerization time was found to have little influence on the properties of the brushes, the monomer feed ratios had a great impact. The 70 % DMAEMA polymer brush had similar height as the 30 % DMAEMA brush after 45 min; however, it had a greater response to pH and morphological change compared to the 30 % DMAEMA. The 70 % DMAEMA brush was used to demonstrate an efficient approach to alleviate the ion suppression effect in MALDI analysis of complex mixtures by effectively fractionating a binary mixture of peptides prior to MALDI-MS analysis. PMID:25253913

  9. [Preparation of a novel polymer monolith using atom transfer radical polymerization method for solid phase extraction].

    PubMed

    Shen, Ying; Qi, Li; Qiao, Juan; Mao, Lanqun; Chen, Yi

    2013-04-01

    In this study, a novel polymer monolith based solid phase extraction (SPE) material has been prepared by two-step atom transfer radical polymerization (ATRP) method. Firstly, employing ethylene glycol dimethacrylate (EDMA) as a cross-linker, a polymer monolith filled in a filter head has been in-situ prepared quickly under mild conditions. Then, the activators generated by electron transfer ATRP (ARGET ATRP) was used for the modification of poly(2-(dimethylamino)ethyl-methacrylate) (PDMAEMA) on the monolithic surface. Finally, this synthesized monolith for SPE was successfully applied in the extraction and enrichment of steroids. The results revealed that ATRP can be developed as a facile and effective method with mild reaction conditions for monolith construction and has the potential for preparing monolith in diverse devices. PMID:23898628

  10. Frictional properties of the end-grafted polymer layer in presence of salt solution

    NASA Astrophysics Data System (ADS)

    Raftari, Maryam; Zhang, Zhenyu; Leggett, Graham J.; Geoghegan, Mark

    2012-02-01

    We have studied the frictional behaviour of grafted poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) films using friction force microscopy (FFM). The films were prepared on native oxide-terminated silicon substrates using the technique of atom transfer radical polymerization (ATRP). These brushes had constant grafting density (1.18 nm2), and of a thickness of ˜66 nm, as measured by ellipsometry. We show that single asperity contact mechanics (Johnson-Kendall-Roberts (JKR) and Derjaguin-M"uller-Toporov (DMT) models) as well as a linear (Amontons) relation between applied load and frictional load all apply to these systems depending on the concentration of salt and the nature of the FFM probe. Measurements were made using gold-coating and polymer functionalized silicon nitride triangular probes. Polymer functionalized probe included growth the PDMAEMA with same method on tips. The frictional behaviour are investigated between PDMAEMA and gold coated and PDMAEMA tips immersed in different concentrations of KCl, KBr and KI.

  11. Bioreducible POSS-cored star-shaped polycation for efficient gene delivery.

    PubMed

    Yang, Yan-Yu; Wang, Xing; Hu, Yang; Hu, Hao; Wu, De-Cheng; Xu, Fu-Jian

    2014-01-22

    The bioreducible star-shaped gene vector (POSS-(SS-PDMAEMA)8) with well-defined structure and relatively narrow molecular weight distribution was synthesized via atom transfer radical polymerization (ATRP) of (2-dimethylamino)ethyl methacrylate (DMAEMA) from a polyhedral oligomeric silsesquioxane (POSS) macroinitiator. POSS-(SS-PDMAEMA)8 was composed of a biocompatible POSS core and eight disulfide-linked PDMAEMA arms, wherein the PDMAEMA chain length could be adjusted by controlling polymerization time. POSS-(SS-PDMAEMA)8 can effectively bind pDNA into uniform nanocomplexes with appropriate particle size and zeta potential. The incorporation of disulfide bridges gave the POSS-(SS-PDMAEMA)8 material facile bioreducibility. In comparison with POSS-(PDMAEMA)8 without disulfide linkage, POSS-(SS-PDMAEMA)8 exhibited much lower cytotoxicity and substantially higher transfection efficiency. The present work would provide useful information for the design of new POSS-based drug/gene carriers. PMID:24299237

  12. Star polymers with a cationic core prepared by ATRP for cellular nucleic acids delivery.

    PubMed

    Cho, Hong Y; Averick, Saadyah E; Paredes, Eduardo; Wegner, Katarzyna; Averick, Amram; Jurga, Stefan; Das, Subha R; Matyjaszewski, Krzysztof

    2013-05-13

    Poly(ethylene glycol) (PEG)-based star polymers with a cationic core were prepared by atom transfer radical polymerization (ATRP) for in vitro nucleic acid (NA) delivery. The star polymers were synthesized by ATRP of 2-(dimethylamino)ethyl methacrylate (DMAEMA) and ethylene glycol dimethacrylate (EGDMA). Star polymers were characterized by gel permeation chromatography, zeta potential, and dynamic light scattering. These star polymers were combined with either plasmid DNA (pDNA) or short interfering RNA (siRNA) duplexes to form polyplexes for intracellular delivery. These polyplexes with either siRNA or pDNA were highly effective in NA delivery, particularly at relatively low star polymer weight or molar ratios, highlighting the importance of NA release in efficient delivery systems. PMID:23560989

  13. Biopolymer as an electron selective layer for inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Jin Tan, Mein; Zhong, Shu; Wang, Rui; Zhang, Zhongxing; Chellappan, Vijila; Chen, Wei

    2013-08-01

    In this work, a solution-processable electron selective layer is introduced for inverted polymer solar cells (PSCs). Cationic biopolymer poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) is used as a solution-processable work function modifier of indium-tin-oxide transparent conducting electrode to yield efficient inverted PSCs of 3.3% under AM1.5G illumination, with poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester as the active layer. Devices using PDMAEMA exhibit greater stability in ambient "working conditions" as compared to devices using ZnO, retaining 90% of peak power conversion efficiency after 8 weeks. Therefore, PDMAEMA has great potential as a universal work function modifier material with high robustness.

  14. Co-delivery of doxorubicin and tumor-suppressing p53 gene using a POSS-based star-shaped polymer for cancer therapy.

    PubMed

    Li, Yongmao; Xu, Bing; Bai, Tao; Liu, Wenguang

    2015-07-01

    In this work, a star-shaped polymer consisting of a cationic poly[2-(dimethylamino) ethyl methacrylate] (PDMAEMA) shell and a zwitterionic poly[N-(3-(methacryloylamino) propyl)-N,N-dimethyl-N-(3-sulfopropyl) ammonium hydroxide] (PMPD) corona was grafted from a polyhedral oligomeric silsesquioxanes (POSS)-based initiator via atomic transfer radical polymerization (ATRP). The reported star-shaped polymer could form stable micelles in aqueous solutions even in the presence of serum. In addition, anti-cancer drug doxorubicin and tumor-suppressing p53 gene were loaded in the process of micelle formation. The formed polyplex was biocompatible and highly efficient for both drug and gene delivery. Furthermore, the polyplex was able to cause a high apoptotic rate of tumor cells both in vitro and in vivo. This combination delivery strategy offers a promising method for cancer therapy and can be used for further clinical applications. PMID:25934448

  15. Revealing the Supramolecular Nature of Side-Chain Terpyridine-Functionalized Polymer Networks

    PubMed Central

    Brassinne, Jérémy; Jochum, Florian D.; Fustin, Charles-André; Gohy, Jean-François

    2015-01-01

    Nowadays, finely controlling the mechanical properties of polymeric materials is possible by incorporating supramolecular motifs into their architecture. In this context, the synthesis of a side-chain terpyridine-functionalized poly(2-(dimethylamino)ethyl methacrylate) is reported via reversible addition-fragmentation chain transfer polymerization. By addition of transition metal ions, concentrated aqueous solutions of this polymer turn into metallo-supramolecular hydrogels whose dynamic mechanical properties are investigated by rotational rheometry. Hence, the possibility for the material to relax mechanical constrains via dissociation of transient cross-links is brought into light. In addition, the complex phenomena occurring under large oscillatory shear are interpreted in the context of transient networks. PMID:25569082

  16. pH-responsive aggregates from double hydrophilic block copolymers carrying zwitterionic groups. Encapsulation of antiparasitic compounds for the treatment of leishmaniasis.

    PubMed

    Karanikolopoulos, Nikos; Pitsikalis, Marinos; Hadjichristidis, Nikos; Georgikopoulou, Kalliopi; Calogeropoulou, Theodora; Dunlap, John R

    2007-04-10

    A series of well-defined poly[(ethylene oxide)-b-2-(dimethylamino)ethyl methacrylate] (PEO-b-PDMAEMA) diblock copolymers were synthesized by atom transfer radical polymerization (ATRP) techniques. Post-polymerization reactions were performed to transform a portion of the tertiary amine groups of the PDMAEpsilonMA into phosphorozwitterions. The aggregation behavior of the prepared zwitterionic block copolymers was investigated by static and dynamic light scattering techniques at 25 and 37 degrees C, in weakly basic and acidic aqueous solutions. Antiparasitic drugs used for the treatment of Leishmania were incorporated into the copolymer aggregates. The effect of the solution pH, the zwitterion content, temperature, and the quantity of the incorporated drug on the aggregation behavior of the copolymers was tested. PMID:17362035

  17. In situ synthesis of cobalt ferrite nanoparticle/polymer hybrid from a mixed Fe-Co methacrylate for magnetic hyperthermia

    NASA Astrophysics Data System (ADS)

    Hayashi, Koichiro; Maeda, Kazuki; Moriya, Makoto; Sakamoto, Wataru; Yogo, Toshinobu

    2012-09-01

    Hyperthermic CoFe2O4 nanoparticle (CFO NP)/polymer hybrids were synthesized by hydrolysis-condensation from a complex of Co and Fe possessing methacrylate ligands. Single-crystal analysis revealed that the complex consisted of two Co and four Fe metal atoms coordinated by methacrylate and 2-methoxyethoxy groups. The complex was copolymerized with 2-hydroxyethyl methacrylate (HEMA) and the resulting copolymer was then hydrolyzed to form a CFO NP/copolymer of poly(methacrylate) and poly(2-hydroxyethyl methacrylate) hybrid. Copolymerization with HEMA enhanced the stability of the hybrid in water. The size and magnetic properties of CFO in the hybrid were controlled by adjusting the hydrolysis conditions. Moreover, the hybrid generated heat under an alternating current magnetic field; its exothermal properties depended on the magnetic properties of the hybrid, the strength of the applied field, and the CFO NP content in the agar phantom matrix.

  18. Comparison of ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) concentrations in hair for testing abstinence.

    PubMed

    Albermann, M E; Musshoff, F; Madea, B

    2011-04-01

    Hair analysis is a powerful tool for retrospective drug analysis. By determining the minor ethanol metabolites ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) in hair, even a previous consumption of alcohol is detectable. However, previous studies showed a lack of correlation if both parameters are determined simultaneously. A further study was conducted to confirm or refute these results. One hundred and sixty hair samples were analyzed for EtG and FAEE in the context of driving ability. In 109 cases, alcohol abstinence was clearly proven and was excluded in 15 cases. In 36 cases, ambiguous results were found. Possible reasons for the deviating results are discussed. It is recommended, that in context of driving ability diagnostics the EtG result is determinant. In critical cases FAEE concentrations can be determined for checking purposes, but a negative FAEE result cannot refute a determined EtG concentration >7 pg/mg. PMID:21127843

  19. Liquid-liquid extraction separation of iron (III) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester.

    PubMed

    Jayachandran, J; Dhadke, P M

    1997-07-01

    Liquid-liquid extraction separation of iron(III) with 2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester (PC-88A) in toluene has been studied. Quantitative extraction of iron(III) with 5 x 10(-3) M PC-88A in toluene is observed in the pH range 0.75-2.5. From the extracted complex species in the organic phase iron(III) was stripped with 1-4 M HNO(3), 1.5-4 M H(2)SO(4) and 1.5-4 M HCl, and later determined spectrophotometrically by thiocyanate method. Separation of iron(III) was carried out with some of the first transition metals in binary and multicomponent mixtures. This method was extended for the determination of iron in real samples. PMID:18966864

  20. Investigation of bonding properties of denture bases to silicone-based soft denture liner immersed in isobutyl methacrylate and 2-hydroxyethyl methacrylate

    PubMed Central

    Tugut, Faik; Mutaf, Burcu; Guney, Umit

    2014-01-01

    PURPOSE The purpose of this study was to investigate the bonding properties of denture bases to silicone-based soft denture liners immersed in isobutyl methacrylate (iBMA) and 2-hydroxyethyl methacrylate (HEMA) for various lengths of time. MATERIALS AND METHODS Polymethyl methacrylate (PMMA) test specimens were fabricated (75 mm in length, 12 mm in diameter at the thickest section, and 7 mm at the thinnest section) and then randomly assigned to five groups (n=15); untreated (Group 1), resilient liner immersed in iBMA for 1 minute (Group 2), resilient liner immersed in iBMA for 3 minutes (Group 3), resilient liner immersed in HEMA for 1 minute (Group 4), and resilient liner immersed in HEMA for 3 minutes (Group 5). The resilient liner specimens were processed between 2 PMMA blocks. Bonding strength of the liners to PMMA was compared by tensile test with a universal testing machine at a crosshead speed of 5 mm/min. Data were evaluated by 1-way ANOVA and post hoc Tukey-Kramer multiple comparisons tests (α=0.05). RESULTS The highest mean value of force was observed in Group 3 specimens. The differences between groups were statistically significant (P<.05), except between Group 1 and Group 4 (P=.063). CONCLUSION Immersion of silicone-based soft denture liners in iBMA for 3 minutes doubled the tensile bond strength between the silicone soft liner and PMMA denture base materials compared to the control group. PMID:24843397

  1. 40 CFR 180.483 - O-[2-(1,1-Dimethylethyl)-5-pyrimidinyl] O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false O- O-ethyl-O-(1-methyl-ethyl) phosphorothioate; tolerances for residues. 180.483 Section 180.483 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.483...

  2. Gas chromatography-mass spectrometry of ethyl palmitate calibration and resolution with ethyl oleate as biomarker ethanol sub acute in urine application study

    NASA Astrophysics Data System (ADS)

    Suaniti, Ni Made; Manurung, Manuntun

    2016-03-01

    Gas Chromatography-Mass Spectrometry is used to separate two and more compounds and identify fragment ion specific of biomarker ethanol such as palmitic acid ethyl ester (PAEE), as one of the fatty acid ethyl esters as early detection through conyugated reaction. This study aims to calibrate ethyl palmitate and develop analysis with oleate acid. This methode can be used analysis ethanol and its chemistry biomarker in ethanol sub-acute consumption as analytical forensic toxicology. The result show that ethanol level in urine rats Wistar were 9.21 and decreased 6.59 ppm after 48 hours consumption. Calibration curve of ethyl palmitate was y = 0.2035 x + 1.0465 and R2 = 0.9886. Resolution between ethyl palmitate and oleate were >1.5 as good separation with fragment ion specific was 88 and the retention time was 18 minutes.

  3. Effect of cholesterol-poly(N,N-dimethylaminoethyl methacrylate) on the properties of stimuli-responsive polymer liposome complexes.

    PubMed

    Alves, P; Hugo, A A; Tymczyszyn, E E; Ferreira, A F; Fausto, R; Pérez, P F; Coelho, J F J; Simões, P N; Gómez-Zavaglia, A

    2013-04-01

    The development of new polymer-liposome complexes (PLCs) as delivery systems is the key issue of this work. Three main areas are dealt with: polymer synthesis/characterization, liposome formulation/characterization and evaluation of the PLCs uptake by eukaryotic cells. Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) with low molecular weight and narrow polydispersity was synthesized by Atom Transfer Radical Polymerization (ATRP). The polymers were synthesized using two different bromide initiators (cholesteryl-2-bromoisobutyrate and ethyl 2-bromoisobutyrate) as a route to afford PDMAEMA and CHO-PDMAEMA. Both synthesized polymers (PDMAEMA and CHO-PDMAEMA) were incorporated in the preparation of lecithin liposomes (LEC) to obtain PLCs. Three polymer/lipid ratios were investigated: 5, 10 and 20%. Physicochemical characterization of PLCs was carried out by determining the zeta potential, particle size distribution, and the release of fluorescent dyes (carboxyfluorescein CF and calcein) at different temperatures and pHs. The leakage experiments showed that CHO covalently bound to PDMAEMA strongly stabilizes PLCs. The incorporation of 5% CHO-PDMAEMA to LEC (LEC_CHO-PD5) appeared to be the stablest preparation at pH 7.0 and at 37°C. LEC_CHO-PD5 destabilized upon slight changes in pH and temperature, supporting the potential use of CHO-PDMAEMA incorporated to lecithin liposomes (LEC_CHO-PDs) as stimuli-responsive systems. In vitro studies on Raw 264.7 and Caco-2/TC7 cells demonstrated an efficient incorporation of PLCs into the cells. No toxicity of the prepared PLCs was observed according to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. These results substantiate the efficiency of CHO-PDMAEMA incorporated onto LEC to assist for the release of the liposome content in mildly acidic environments, like those found in early endosomes where pH is slightly lower than the physiologic. In summary, the main achievements of this work are: (a) novel

  4. Arrested coalescence behaviour of giant Pickering droplets and colloidosomes stabilised by poly(tert-butylaminoethyl methacrylate) latexes.

    PubMed

    Morse, Andrew J; Tan, Sin-Ying; Giakoumatos, Emma C; Webber, Grant B; Armes, Steven P; Ata, Seher; Wanless, Erica J

    2014-08-21

    The coalescence of two oil droplets grown at pH 10 in the presence of lightly cross-linked 260 nm diameter charge-stabilised poly(tert-butylamino)ethyl methacrylate (PTBAEMA) latexes was monitored using a high-speed video camera. Three model oils (n-dodecane, isopropyl myristate and sunflower oil) were investigated, each in the absence and presence of an oil-soluble cross-linker [tolylene 2,4-diisocyanate-terminated poly(propylene glycol), PPG-TDI]. In the absence of PPG-TDI, rapid coalescence was observed for giant PTBAEMA-stabilised Pickering oil droplets, which exhibited faster coalescence times compared to bare oil droplets. However, an increase in the damping coefficients for coalescing Pickering droplets (compared to those of bare oil droplets) indicated PTBAEMA latex particle adsorption. Addition of PPG-TDI cross-linker to oil droplets in the absence of latex particles led to a reduction in the interfacial tension confirming its surface-active nature. The oil-soluble PPG-TDI reacts with the secondary amine groups on the PTBAEMA latex, producing giant colloidosomes that remain stable to coalescence when brought into contact. This stability to coalescence was not observed for bare oil droplets in the presence of PPG-TDI, confirming that the cross-linked latex particles at the interface provide the additional stability. Finally, interactions between asymmetric n-dodecane droplets were examined. Adding oil-soluble cross-linker to only one droplet resulted in "arrested coalescence" behaviour in the presence of PTBAEMA latex particles. In this context, the droplet ageing time was found to be critical and is attributed to the relatively slow particle adsorption kinetics. Ageing times of less than 60 s led to catastrophic droplet coalescence, whereas ageing times longer than 60 s indicated cross-linker diffusion from one droplet to the other, which produced inter-cross-linked colloidosomes. Arrested coalescence was only observed for ageing times of approximately 60

  5. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer. 177.1030 Section 177.1030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...

  6. Recent Origin of the Methacrylate Redox System in Geobacter sulfurreducens AM-1 through Horizontal Gene Transfer

    PubMed Central

    Arkhipova, Oksana V.; Meer, Margarita V.; Mikoulinskaia, Galina V.; Zakharova, Marina V.; Galushko, Alexander S.; Kondrashov, Fyodor A.

    2015-01-01

    The origin and evolution of novel biochemical functions remains one of the key questions in molecular evolution. We study recently emerged methacrylate reductase function that is thought to have emerged in the last century and reported in Geobacter sulfurreducens strain AM-1. We report the sequence and study the evolution of the operon coding for the flavin-containing methacrylate reductase (Mrd) and tetraheme cytochrome с (Mcc) in the genome of G. sulfurreducens AM-1. Different types of signal peptides in functionally interlinked proteins Mrd and Mcc suggest a possible complex mechanism of biogenesis for chromoproteids of the methacrylate redox system. The homologs of the Mrd and Mcc sequence found in δ-Proteobacteria and Deferribacteres are also organized into an operon and their phylogenetic distribution suggested that these two genes tend to be horizontally transferred together. Specifically, the mrd and mcc genes from G. sulfurreducens AM-1 are not monophyletic with any of the homologs found in other Geobacter genomes. The acquisition of methacrylate reductase function by G. sulfurreducens AM-1 appears linked to a horizontal gene transfer event. However, the new function of the products of mrd and mcc may have evolved either prior or subsequent to their acquisition by G. sulfurreducens AM-1. PMID:25962149

  7. 21 CFR 177.2465 - Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers. 177.2465 Section 177.2465 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  8. 21 CFR 177.2465 - Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers. 177.2465 Section 177.2465 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  9. 21 CFR 177.2465 - Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polymethylmethacrylate/poly(trimethoxysilylpropyl)methacrylate copolymers. 177.2465 Section 177.2465 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended...

  10. 40 CFR 721.7200 - Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Perfluoroalkyl aromatic carbamate modified alkyl methacrylate copolymer. 721.7200 Section 721.7200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific...

  11. Use of methacrylate-modified chitosan to increase the durability of dentine bonding systems.

    PubMed

    Diolosà, Marina; Donati, Ivan; Turco, Gianluca; Cadenaro, Milena; Di Lenarda, Roberto; Breschi, Lorenzo; Paoletti, Sergio

    2014-12-01

    This study aimed at investigating the effect of a methacrylate-modified chitosan on the durability of adhesive interfaces to improve the clinical performance of dental restorations. Chitosan was modified with methacrylic acid (Chit-MA70) on 16% of the amino groups. Viscosity, rheology, and (1)H NMR spectroscopy were performed to characterize the modified polysaccharide. Chit-MA70 was blended into a primer of an "etch-and-rinse" experimental adhesive system and tested on human teeth. The presence of methacrylate moieties and of residual positive charges on the polysaccharide chain allowed Chit-MA70 to covalently bind to the restorative material and electrostatically interact with demineralized dentin. The Chit-MA70 containing an adhesive system showed values of the immediate bond strength (26.0 ± 8.7 MPa) comparable to the control adhesive system (25.5 ± 8.7 MPa). However, it was shown that upon performing thermo-mechanical cycling treatment of the dental restoration on human teeth, the adhesive with the methacrylate-modified chitosan, in variance with the control adhesive, did not show any decrease in the bond strength (28.4 ± 8.8 MPa). The modified chitosan is proposed as a component of the "etch-and-rinse" adhesive system to efficiently improve the durability of dental restorations. PMID:25347288

  12. Versatility of Alkyne-Modified Poly(Glycidyl Methacrylate) Layers for Click Reactions

    SciTech Connect

    Soto-Cantu, Dr. Erick; Lokitz, Bradley S; Hinestrosa Salazar, Juan Pablo; Deodhar, Chaitra; Messman, Jamie M; Ankner, John Francis; Kilbey, II, S Michael

    2011-01-01

    Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for 'click' chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using 'click' chemistry, and grafting densities in the range of 0.007-0.95 chains nm{sup -2} were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm{sup -3}. The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.

  13. Enthalpy of mixing of methacrylic acid with organic solvents at 293 K

    NASA Astrophysics Data System (ADS)

    Sergeev, V. V.

    2016-03-01

    The enthalpies of mixing of binary systems of methacrylic acid with acetonitrile, benzene, hexane, 1,2-dichloroethane, and acetic acid are measured calorimetrically at 293 K and atmospheric pressure. The enthalpy of mixing of all the studied binary systems is positive over the range of concentrations.

  14. Labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine in hepatic RNA of mice given[ethyl-1,2(-3)H or ethyl-1(-14)C]ethyl carbamate (urethan).

    PubMed

    Ribovich, M L; Miller, J A; Miller, E C; Timmins, L G

    1982-01-01

    Injection of a single dose of[ethyl-1,2(-3)H]or[ethyl-1(-14C]- ethyl carbamate into 12-day old male[C57BL/6 x C3H/He]F1 mice or of[ethyl-1,2(-3H]ethyl carbamate into adult male A/Jax mice resulted in the formation of labeled 1,N6-ethenoadenosine and 3,N4-ethenocytidine adducts in the hepatic RNA. These adducts were characterized by comigration on h.p.l.c. of 3H or 14C in enzymatic hydrolysates of the RNA with synthetic standards. Both the ethenoadenosine and ethenocytidine were further characterized by their conversion to acetylated products that comigrated with acetylated synthetic standards. The ethenoadenosine was also converted by anhydrous trifluoroacetic acid to a product that comigrated with synthetic 1,N6-ethenoadenine. The levels of adducts in the hepatic RNA 12 h after a single injection of 0.5-0.6 mg of ethyl carbamate/g body weight were 6-10 and 2-3 pmol/mg RNA of ethenoadenosine and ethenocytidine, respectively. No labeled ethenoadenosine or ethenocytidine could be detected in the hepatic RNA of mice given[1-14C]ethanol, an enzymatic hydrolysis product of ethyl carbamate. These data indicate that ethyl carbamate may be metabolically activated by dehydrogenation to vinyl carbamate and subsequent epoxidation of the latter compound as previously proposed. Vinyl carbamate epoxide may form etheno derivatives in a manner analogous to that demonstrated for chloroethylene oxide, an electrophilic metabolite of vinyl chloride. Vinyl carbamate has been shown to have the same spectrum of tumor induction as ethyl carbamate but to be much more active than the latter carcinogen. PMID:6178529

  15. Thermal Decomposition of Ethyl Formate behind the Reflected Shock Waves in the Temperature Range of 909-1258K

    NASA Astrophysics Data System (ADS)

    Balaganesh, M.; Sudhakar, G.; Rajakumar, B.

    Ethyl formate is the simplest model of ethyl esters which are considered as biodiesel. Systematic tests on properties and reactivity of biodiesel have been reported[1, 2]. Methyl and ethyl ester mix can offer improved physical properties. Generally, ethyl esters are slightly more reactive than the methyl esters[3]. Also ethyl formate is an interstellar molecule. It was first detected in interstellar space by Belloche et al.[4]. So studies of this molecule are required to understand the fuel properties and interstellar chemistry.

  16. Impact strength of a modified continuous glass fiber--poly(methyl methacrylate).

    PubMed

    Vallittu, P K; Narva, K

    1997-01-01

    The effect of fiber reinforcement of autopolymerizing poly(methyl methacrylate) was investigated. The impact strength of continuous E-glass fiber-poly(methyl methacrylate) composite was determined. Rectangular test specimens (n = 10 per group) were modified by incorporating an additional fiber reinforcement of untreated E-glass fibers, silanized E-glass fibers, or aramid fibers in the test specimens. Controls were either unreinforced or reinforced from the middle of the test specimen only. The impact strength of the specimens was measured by using a charpy-type pendulum impact tester after the specimens had been stored in water at 37 degrees C for 4 weeks. After the impact strength test, the length of the delamination of poly(methyl methacrylate) from the fibers was measured and plotted to the impact strength of the test specimens by using a linear regression model. The impact strength of unreinforced autopolymerizing poly(methyl methacrylate) was 7.8 kl/m2, while incorporation of glass fiber reinforcement with a fiber concentration of 12.4 wt% increased the impact strength to 74.7 kl/m2 (P = .000). The additional fiber reinforcement of the test specimen did not affect the impact strength (P = .363). Delamination negatively correlated with the impact strength of the test specimens (r = -.72, P = .000). The results of this study suggest that glass fiber reinforcement enhanced the impact strength of autopolymerizing poly(methyl methacrylate), while the use of additional fiber reinforcement made of aramid or glass fibers in the test specimens did not have an effect on the impact strength. PMID:9206454

  17. Investigation of thiol-ene and thiol-ene-methacrylate based resins as dental restorative materials

    PubMed Central

    Cramer, Neil B.; Couch, Charles L.; Schreck, Kathleen M.; Carioscia, Jacquelyn A.; Boulden, Jordan E.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2009-01-01

    Objectives The objective of this work was to evaluate thiol-norbornene and thiol-ene-methacrylate systems as the resin phase of dental restorative materials and demonstrate their superior performance as compared to dimethacrylate materials. Methods Polymerization kinetics and overall functional group conversions were determined by Fourier transform infrared spectroscopy (FTIR). Flexural strength and modulus were determined with a 3-point flexural test. Polymerization-induced shrinkage stress was measured with a tensometer. Results Thiol-ene polymer systems were demonstrated to exhibit advantageous properties for dental restorative materials in regards to rapid curing kinetics, high conversion, and low shrinkage and stress. However, both the thiol-norbornene and thiol-allyl ether systems studied here exhibit significant reductions in flexural strength and modulus relative to BisGMA/TEGDMA. By utilizing the thiol-ene component as the reactive diluent in dimethacrylate systems, high flexural modulus and strength are achieved while dramatically reducing the polymerization shrinkage stress. The methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems both exhibited equivalent flexural modulus (2.1 ± 0.1 GPa) and slightly reduced flexural strength (95 ± 1 and 101 ± 3 MPa, respectively) relative to BisGMA/TEGDMA (flexural modulus; 2.2 + 0.1 GPa and flexural strength; 112 ± 3 MPa). Both the methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems exhibited dramatic reductions in shrinkage stress (1.1 ± 0.1 and 1.1 ± 0.2 MPa, respectively) relative to BisGMA/TEGDMA (2.6 ± 0.2 MPa). Significance The improved polymerization kinetics and overall functional group conversion, coupled with reductions in shrinkage stress while maintaining equivalent flexural modulus, result in a superior overall dental restorative material as compared to traditional bulk dimethacrylate resins. PMID:19781757

  18. Synthesis and evaluation of novel siloxane-methacrylate monomers used as dentin adhesives

    PubMed Central

    Ge, Xueping; Ye, Qiang; Song, Linyong; Misra, Anil; Spencer, Paulette

    2014-01-01

    Objectives The objectives of this study were to synthesize two new siloxane-methacrylate (SM) monomers for application in dentin adhesives and to investigate the influence of different functionality of the siloxane-containing monomers on the adhesive photopolymerization, water sorption, and mechanical properties. Materials and method Two siloxane-methacrylate monomers (SM1 and SM2) with four and eight methacrylate groups were synthesized. Dentin adhesives containing BisGMA, HEMA and the siloxane-methacrylate monomers were photo-polymerized. The experimental adhesives were compared with the control adhesive (HEMA/BisGMA 45/55 w/w) and characterized with regard to degree of conversion (DC), water miscibility of the liquid resin, water sorption and dynamic mechanical analysis (DMA). Results The experimental adhesives exhibited improved water miscibility as compared to the control. When cured in the presence of 12 wt % water to simulate the wet environment of the mouth, the SM-containing adhesives showed DC comparable to the control. The experimental adhesives showed higher rubbery modulus than the control under dry conditions. Under wet conditions, the mechanical properties of the formulations containing SM monomer with increased functionality were comparable with the control, even with more water sorption. Significance The concentration and functionality of the newly synthesized siloxane-methacrylate monomers affected the water miscibility, water sorption and mechanical properties of the adhesives. The experimental adhesives show improved water compatibility compared with the control. The mechanical properties were enhanced with an increase of the functionality of the siloxane-containing monomers. The results provide critical structure/property relationships and important information for future development of durable, versatile siloxane-containing dentin adhesives. PMID:24993811

  19. Influence of Gilbert's syndrome on the formation of ethyl glucuronide.

    PubMed

    Huppertz, Laura M; Gunsilius, Leonie; Lardi, Christelle; Weinmann, Wolfgang; Thierauf-Emberger, Annette

    2015-09-01

    A drinking experiment with participants suffering from Gilbert's syndrome was performed to study the possible influence of this glucuronidation disorder on the formation of ethyl glucuronide (EtG). Gilbert's syndrome is a rather common and, in most cases, asymptomatic congenital metabolic aberration with a prevalence of about 5 %. It is characterized by a reduction of the enzyme activity of the uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 up to 80 %. One of the glucuronidation products is EtG, which is formed in the organism following exposure to ethanol. EtG is used as a short-term marker for ethyl alcohol consumption to prove abstinence in various settings. After 2 days of abstinence from ethanol and giving a void urine sample, 30 study participants drank 0.1 L of sparkling wine (9 g ethanol). 3, 6, 12, and 24 h after drinking, urine samples were collected. 3 hours after drinking, an additional blood sample was taken, in which liver enzyme activities, ethanol, hematological parameters, and bilirubin were measured. EtG and ethyl sulfate (EtS), another short-term marker of ethanol consumption, were determined in the urine samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS); creatinine was measured photometrically. In all participants, EtG and EtS were detected in concentrations showing a wide range (EtG: 3 h sample 0.5-18.43 mg/L and 6 h sample 0.67-13.8 mg/L; EtS: 3 h sample 0.87-6.87 mg/L and 6 h sample 0.29-4.48 mg/L). No evidence of impaired EtG formation was found. Thus, EtG seems to be a suitable marker for ethanol consumption even in individuals with Gilbert's syndrome. PMID:25680552

  20. Micellar phase boundaries under the influence of ethyl alcohol.

    PubMed

    Bergeron, Denis E

    2016-03-01

    The Compton spectrum quenching technique is used to monitor the effect of ethyl alcohol (EtOH) additions on phase boundaries in two systems. In toluenic solutions of the nonionic surfactant, Triton X-100, EtOH shifts the boundary separating the first clear phase from the first turbid phase to higher water:surfactant ratios. In a commonly used scintillant, Ultima Gold AB, the critical micelle concentration is not shifted. The molecular interactions behind the observations and implications for liquid scintillation counting are discussed. PMID:26585642

  1. Ethyl alcohol boiling heat transfer on multilayer meshed surfaces

    NASA Astrophysics Data System (ADS)

    Dåbek, Lidia; Kapjor, Andrej; Orman, Łukasz J.

    2016-06-01

    The paper presents the problem of heat transfer enhancement with the application of multilayer metal mesh structures during boiling of ethyl alcohol at ambient pressure. The preparation of samples involved sintering fine copper meshes with the copper base in the reduction atmosphere in order to prevent oxidation of the samples. The experiments included testing up to 4 layers of copper meshes. Significant augmentation of boiling heat transfer is possible, however, considerable number of meshes actually hinders heat transfer conditions and leads to the reduction in the heat flux transferred from the heater surface.

  2. Photoelectron spectroscopic study of the ethyl cyanoacrylate anion

    NASA Astrophysics Data System (ADS)

    Zhang, Xinxing; Tang, Xin; Bowen, Kit

    2013-09-01

    Anion photoelectron spectroscopy and density functional theory have been utilized to study the parent, ethyl cyanoacrylate molecular anion, ECA-. The measured electron affinity (0.9 ± 0.2 eV), vertical detachment energy (1.3 ± 0.1 eV), and anion-to-triplet neutral, photodetachment transition energies (4.0 ± 0.1 eV and 4.5 ± 0.1 eV) all compare well with their calculated values. The relatively high electron affinity of the ECA monomer is responsible for the fact that its “anionic” polymerization mechanism proceeds even with weak nucleophiles, such as water.

  3. Ethyl Pyruvate Combats Human Leukemia Cells but Spares Normal Blood Cells.

    PubMed

    Birkenmeier, Gerd; Hemdan, Nasr Y A; Kurz, Susanne; Bigl, Marina; Pieroh, Philipp; Debebe, Tewodros; Buchold, Martin; Thieme, Rene; Wichmann, Gunnar; Dehghani, Faramarz

    2016-01-01

    Ethyl pyruvate, a known ROS scavenger and anti-inflammatory drug was found to combat leukemia cells. Tumor cell killing was achieved by concerted action of necrosis/apoptosis induction, ATP depletion, and inhibition of glycolytic and para-glycolytic enzymes. Ethyl lactate was less harmful to leukemia cells but was found to arrest cell cycle in the G0/G1 phase. Both, ethyl pyruvate and ethyl lactate were identified as new inhibitors of GSK-3β. Despite the strong effect of ethyl pyruvate on leukemia cells, human cognate blood cells were only marginally affected. The data were compiled by immune blotting, flow cytometry, enzyme activity assay and gene array analysis. Our results inform new mechanisms of ethyl pyruvate-induced cell death, offering thereby a new treatment regime with a high therapeutic window for leukemic tumors. PMID:27579985

  4. A study of plasma reaction mechanisms and kinetics in glow discharges of methyl methacrylate and related precursors using in situ FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Pan, Yu-Chi Vickie

    In order to understand plasma deposition processes, it is important to have a knowledge of the plasma gas-phase reactions. In this project, in situ Fourier Transform Infrared Spectroscopy (FTIR) was utilized to study the plasma gas-phase chemistry in a capacitively coupled glow discharge. Gas-phase measurements of a number of organic plasmas were performed. The precursors include methyl methacrylate (MMA), methyl crotonate, methyl isobutyrate, ethyl methacrylate, vinyl acetate, isopropanol, methanol, tetramethyl cyclobutanedione and formaldehyde. However, MMA was studied most extensively. In addition to the gas-phase study, plasma polymerized films were also characterized. A number of dissociation products were detected by FTIR in the plasmas. Calibration curves of these products and some monomers were prepared to determine the species concentrations and gas-phase composition. Plasma reaction kinetics were studied in closed systems to determine parameters such as dissociation pathway efficiencies, monomer decomposition rate coefficients, and intermediate species decomposition rate coefficients. The study shows that there are two major electron-impact induced dissociation pathways in MMA plasmas: the C-O bond cleavage reaction and decarboxylations. The C-O bond cleavage reaction accounts for approximately half of the MMA dissociation, and neutral formaldehyde and dimethyl ketene (DMK) molecules are produced via intramolecular rearrangement. Decarboxylation reactions produce CO, COsb2 and a number of radicals that subsequently stabilize to form neutral molecules, such as propylene, allene and methanol. These intermediate species then further dissociate in the plasma to small hydrocarbons (methane, acetylene and ethylene), CO, COsb2 and Hsb2. The reaction mechanisms in the plasmas of other alpha ,beta-unsaturated esters and vinyl acetate were found to be similar to the MMA mechanisms. However, the saturated ester (methyl isobutyrate) and isopropanol plasmas were found

  5. Genotoxicity and cytotoxicity assessment of new ethyl-carbamates with ixodicidal activity.

    PubMed

    Prado-Ochoa, María Guadalupe; Muñoz-Guzmán, Marco Antonio; Vázquez-Valadez, Víctor Hugo; Velázquez-Sánchez, Ana María; Salazar, Ana María; Ramírez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

    2016-09-01

    The mammalian erythrocyte micronucleus test was used on the peripheral blood of Wistar rats exposed to two new ethyl-carbamates: ethyl-4-bromophenyl-carbamate (LQM 919) and ethyl-4-chlorophenyl-carbamate (LQM 996) to analyze their genotoxic potential. The mitotic index and cell proliferation kinetics in human lymphocyte cultures in the presence of these ethyl-carbamates were used to evaluate cytotoxicity and cytostaticity respectively. Exposure to greater acute doses (300mg/kg) and to all of the subchronic doses (12.5, 25 and 50mg/kg daily for 90 days) of these ethyl-carbamates induced an increased frequency (p<0.05) of micro-nucleated polychromatic erythrocytes (MN-PCE) compared with rats not exposed to the ethyl-carbamates. Increases in MN-PCE was higher in males than in females exposed to LQM 996 50mg/Kg (p<0.05). All observed changes in rats return 21days after suspending ethyl-carbamate exposure. The highest concentration (0.3mM) of both ethyl-carbamates in lymphocyte cultures increased the percentage of cells in first division metaphase and decreased the percentage of cells in third division metaphase, indicating an increase in cell cycle length or a possible cell cycle arrest in metaphase (cytostatic effect). The results of this study show that the evaluated ethyl-carbamates may induce genotoxic damage in rats and alterations in the human lymphocyte cell cycle. PMID:27542710

  6. Detection of ethyl glucuronide in blood spotted on different surfaces.

    PubMed

    Winkler, M; Kaufmann, E; Thoma, D; Thierauf, A; Weinmann, W; Skopp, G; Alt, A

    2011-07-15

    This study aims to show that sensitive detection of ethyl glucuronide in dried blood spotted onto various surfaces after a period of 24h is feasible. At present, there is insufficient information how tightly ethyl glucuronide (EtG) binds to various materials and how easily it can be eluted. 4ml aliquots of blood samples obtained from seven volunteers after consumption of alcoholic beverages were applied to six different surfaces. After drying and a 24h-storage at 20±2°C the samples were re-dissolved in water, and EtG was subsequently analyzed by a LC-MS Paul-type ion trap. A comparison was made between dried and corresponding fluid samples. EtG was detectable in all subjects' samples following consumption of alcohol. EtG was also detectable after a storage time of four weeks at 4°C in whole blood that had been preserved with EDTA. EtG was detectable in all samples dried on different surfaces and its concentration remained relatively constant irrespective of the particular condition of the material. Detection of EtG in blood spots from the scene may indicate recent alcohol consumption in cases where collection of blood remained undone or could not be performed. PMID:21641739

  7. Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

    PubMed Central

    Kelle, Ilker; Akkoc, Hasan; Tunik, Selcuk; Nergiz, Yusuf; Erdinc, Meral; Erdinc, Levent

    2014-01-01

    This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity. PMID:26019553

  8. DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION

    SciTech Connect

    Tercero, B.; Cernicharo, J.; Lopez, A.; Caro, G. M. Munoz; Kleiner, I.; Nguyen, H. V. L. E-mail: jcernicharo@cab.inta-csic.es E-mail: munozcg@cab.inta-csic.es E-mail: nguyen@pc.rwth-aachen.de

    2013-06-10

    We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

  9. Transesterification process to manufacture ethyl ester of rape oil

    SciTech Connect

    Korus, R.A.; Hoffman, D.S.; Bam, N.; Peterson, C.L.; Drown, D.C.

    1993-12-31

    A process for the production of the ethyl ester of winter rape [EEWR] for use as a biodiesel fuel has been studied. The essential part of the process is the transesterification of rape oil with ethanol, in the presence of a catalyst, to yield the ethyl ester of rape oil as a product and glycerin as a by-product. Experiments have been performed to determine the optimum conditions for the preparation of EEWR. The process variables were: (1) temperature, (2) catalyst, (3) rate of agitation, (4) water content of the alcohol used, and (5) the amount of excess alcohol used. The optimum conditions were: (1) room temperature, (2) 0.5% sodium methoxide or 1% potassium hydroxide catalyst by weight of rapeseed oil, (3) extremely vigorous agitation with some splashing during the initial phase of the reaction and agitation was not necessary after the reaction mixture became homogeneous, (4) absolute ethanol was necessary for high conversion, and (5) 50% excess ethanol with NaOCH{sub 3} or 100% excess with KOH gave a maximum conversion. Viscosity, cloud point and pour point of the EEWR were measured. A preliminary break-even cost for the commercial production of EEWR was found to be $0.55/liter [$2.08/US gallon].

  10. Highly sensitive poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] brush-based flow-through microarray immunoassay device.

    PubMed

    Liu, Yingshuai; Wang, Wei; Hu, Weihua; Lu, Zhisong; Zhou, Xiaoqun; Li, Chang Ming

    2011-08-01

    Flow-through immunoassay is an attractive method for fast, inexpensive and high-throughput protein analyses. However, its practical application is limited by low sensitivity. In this work, a highly sensitive flow-through microarray immunoassay device is developed, in which a poly[glycidyl methacrylate-co-poly(ethylene glycol) methacrylate] (P(GMA-co-PEGMA)) brush as a flexible matrix is uniformly coated on a glass slide through a purge-free surface-initiated atom transfer radical polymerization (SI-ATRP) to immobilize capture proteins for a larger loading capacity and higher bioactivity while allowing easy target access to the brush-attached probes for efficient antibody-antigen (Ab-Ag) bindings. The integrated device is then constructed by simply laminating the protein-arrayed slide onto a ready-for-bonding double-sided adhesive tape-attached poly(methyl methacrylate) (PMMA) microfluidic structure. As a demonstration, a parallel microarray panel is designed to perform flow-through immunoassays for good detection flexibility and simultaneous analysis of various samples. The limit of detection (LOD) of 1-10 pg/mL for detected target proteins is achieved, which is one to two orders better than those of reported flow-through immunoassays. The device also demonstrates significantly reduced total assay time over the static microarray immunoassay. The rapid and sensitive detection can be mainly ascribed to the P(GMA-co-PEGMA) brushed substrate, of which both the hydrophilicity from its PEG component and the binding capability from its GMA moiety result in higher protein loading capacity, lower nonspecific adsorption, and higher Ab-Ag binding efficiency. The integrated microfluidic device was further used to detect an important cancer biomarker carcinoembryonic antigen (CEA) in serum and achieved a LOD of 10 pg/mL, demonstrating its great potential for clinical applications. PMID:21547537

  11. Synthesis of [.sup.13C] and [.sup.2H] substituted methacrylic acid, [.sup.13C] and [.sup.2H] substituted methyl methacrylate and/or related compounds

    DOEpatents

    Alvarez, Marc A.; Martinez, Rodolfo A.; Unkefer, Clifford J.

    2008-01-22

    The present invention is directed to labeled compounds of the formulae ##STR00001## wherein Q is selected from the group consisting of --S--, --S(.dbd.O)--, and --S(.dbd.O).sub.2--, Z is selected from the group consisting of 1-naphthyl, substituted 1-naphthyl, 2-naphthyl, substituted 2-naphthyl, and phenyl groups with the structure ##STR00002## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are each independently selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl, a halogen, and an amino group selected from the group consisting of NH.sub.2, NHR and NRR' where R and R' are each independently selected from the group consisting of a C.sub.1-C.sub.4 lower alkyl, an aryl, and an alkoxy group, and X is selected from the group consisting of hydrogen, a C.sub.1-C.sub.4 lower alkyl group, and a fully-deuterated C.sub.1-C.sub.4 lower alkyl group. The present invention is also directed to a process of preparing labeled compounds, e.g., process of preparing [.sup.13C]methacrylic acid by reacting a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13CH.sub.2)-- aryl sulfone precursor with .sup.13CHI to form a (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate, and, reacting the (CH.sub.3CH.sub.2O--.sup.13C(O)--.sup.13C(.sup.13CH.sub.3).sub.2)-- aryl sulfone intermediate with sodium hydroxide, followed by acid to form [.sup.13C]methacrylic acid. The present invention is further directed to a process of preparing [.sup.2H.sub.8]methyl methacrylate by reacting a (HOOC--C(C.sup.2H.sub.3).sub.2-- aryl sulfinyl intermediate with CD.sub.3I to form a (.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate, and heating the(.sup.2H.sub.3COOC--C(C.sup.2H.sub.3).sub.2)-- aryl sulfinyl intermediate at temperatures and for time sufficient to form [.sup.2H.sub.8]methyl methacrylate.

  12. ATOM TRANSFER RADICAL POLYMERIZATION OF N-BUTYL METHACRYLATE IN AQUEOUS DISPERSED SYSTEMS: A MINIEMULSION APPROACH. (R826735)

    EPA Science Inventory

    Ultrasonication was applied in combination with a hydrophobe for the copper-mediated atom transfer radical polymerization of n-butyl methacrylate in an aqueous dispersed system. A controlled polymerization was successfully achieved, as demonstrated by a linear correlation between...

  13. Process for producing a well-adhered durable optical coating on an optical plastic substrate. [abrasion resistant polymethyl methacrylate lenses

    NASA Technical Reports Server (NTRS)

    Kubacki, R. M. (Inventor)

    1978-01-01

    A low temperature plasma polymerization process is described for applying an optical plastic substrate, such as a polymethyl methacrylate lens, with a single layer abrasive resistant coating to improve the durability of the plastic.

  14. A rare case of pseudotumor formation associated with methyl methacrylate hypersensitivity in a patient following cemented total knee arthroplasty.

    PubMed

    Kenan, Shachar; Kahn, Leonard; Haramati, Noga; Kenan, Samuel

    2016-08-01

    Hypersensitivity to orthopedic implant materials has been well documented with potential catastrophic consequences if not addressed pre-operatively. The spectrum of reactions is wide, from mild non-specific pain with localized erythema to severe periprosthetic inflammatory destruction and pseudotumor formation. It is therefore essential to identify patients who have or are at risk for implant-associated hypersensitivity. Although metal sensitivity is commonly cited as the cause of these reactions, methyl methacrylate (MMA) has rarely been implicated. To the best of our knowledge, methyl methacrylate-associated pseudotumor formation has not yet been described. The following is a case report of a 68-year-old female who, after undergoing a routine cemented right total knee arthroplasty, developed a painless, enlarging mass during a 13-year period. This mass was found to be a pseudotumor in association with methyl methacrylate hypersensitivity. A review of pseudotumor pathogenesis, methyl methacrylate hypersensitivity, and preoperative preventative care is discussed. PMID:27022733

  15. Studies on acrylated epoxydised triglyceride resin-co-butyl methacrylate towards the development of biodegradable pressure sensitive adhesives.

    PubMed

    David, S Begila; Sathiyalekshmi, K; Gnana Raj, G Allen

    2009-12-01

    The potential chemical utility of Soya bean oil for the preparation of novel biodegradable polymeric pressure sensitive adhesive has been investigated. Epoxy resin was prepared through in situ epoxidation of Soya bean oil under controlled reaction conditions. Acrylated epoxidised triglyceride resin (AET resin) and copolymer of AET resin with butyl methacrylate were prepared and evaluated. Higher the concentration of butyl methacrylate higher is the degree of copolymerization of AET resin with butyl methacrylate. An optimum concentration of AET resin with butyl methacrylate (100 : 0.40) yields favourable shear holding time and peel strength to qualify as pressure sensitive adhesive. The candidate PSA formulation is biodegradable with antimicrobial activity against gram positive S. aureus ATCC 25923. PMID:18584126

  16. Preparation and characterization of poly(isobutyl methacrylate) microbeads with grafted amidoxime groups

    NASA Astrophysics Data System (ADS)

    Çaykara, Tuncer; Alaslan, Şerife Şirin; Gürü, Metin; Bodugöz, Hatice; Güven, Olgun

    2007-10-01

    Poly(isobutyl methacrylate) (PiBMA) microspheres with a 800- to 1500-μm diameter range synthesized by suspension polymerization technique were used as the trunk polymer in the preparation of a highly efficient new adsorbent. Glycidyl methacrylate (GMA) was grafted onto the trunk polymer by pre-irradiation grafting technique. Grafting conditions were optimized, and GMA grafted PiBMA beads were modified with iminodiacetonitrile (IDAN) in ethanol at 80 °C. The nitrile groups were then amidoximated by using 6% (m/v) hydroxylamine hydrochloride in methanol solution. The IDAN modification and the conversion of the nitrile groups to amidoxime were followed by FT-IR spectroscopy. The surface morphology and thermal behavior of the PiBMA and its modificated forms were also characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques further confirming modification and amidoximation.

  17. Grafting of Chitosan and Chitosantrimethoxylsilylpropyl Methacrylate on Single Walled Carbon Nanotubes-Synthesis and Characterization

    PubMed Central

    Carson, Laura; Kelly-Brown, Cordella; Stewart, Melisa; Oki, Aderemi; Regisford, Gloria; Stone, Julia; Traisawatwong, Pasakorn; Durand-Rougely, Clarissa; Luo, Zhiping

    2011-01-01

    Acid functionalized single walled carbon nanotubes (CNTs) were grafted to chitosan by first reacting the oxidized CNTs with thionyl chloride to form acyl-chlorinated CNTs. This product was subsequently dispersed in chitosan and covalently grafted to form CNT-chitosan. CNT-chitosan was further grafted onto 3-trimethoxysilylpropyl methacrylate by free radical polymerization conditions, to yield CNT-g-chitosan-g-3-trimethoxysilylpropyl methacrylate (TMSPM), hereafter referred to as CNT-chitosan-3-TMSPM. These composites were characterized by Fourier Transform Infrared Resonance Spectroscopy (FTIR), carbon-13 nuclear magnetic resonance (13C NMR), Thermogravimetric Analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The composite showed improved thermal stability and could be of great potential use in bone tissue engineering. PMID:21765959

  18. Influence of pulse width on ultraviolet laser ablation of poly(methyl methacrylate)

    NASA Astrophysics Data System (ADS)

    Srinivasan, R.; Braren, Bodil

    1988-10-01

    The etching of poly(methyl methacrylate) using pulses of 248 nm laser radiation which had a full width at half maximum (FWHM) of 40-100 ns is reported. These pulses were created by combining two identical pulses, each of 40 ns FWHM, with a set time delay. The etch depth/pulse is sensitive to the pulse width and, therefore, the power density in this polymer. It can be explained by the changes in absorptivity during a pulse that have been reported by G. M. Davis and M. C. Gower [J. Appl. Phys. 61, 2090 (1987)]. The shape of the pulse was also found to influence the etch depth/pulse. The etching of polyimide by these extended pulses shows trends that are opposite to those observed in poly(methyl methacrylate). In this instance, the shielding of the latter portion of the incoming pulse by the products that are ablated by the front portion is probably a serious effect.

  19. Rapid preparation and characterization of methacrylate-based monoliths for chromatographic and electrophoretic separation.

    PubMed

    Fan, Li-Qun; Zhang, Yu-Ping; Gong, Wen-Jun; Qu, Ling-Bo; Lee, Kwang-Pill

    2010-01-01

    Butyl-methacrylate-based porous monoliths were rapidly prepared in the fused-silica capillary with a 10-cm stripe of polyimide removed from its exterior. The photopolymerization could be carried out in 150 s using ethylene glycol dimethacrylate as a cross-linking agent; 1-propanol, 1,4-butanediol, and water as tri-porogenic solvents; and Irgacure 1800 as a photo-initiator. The effect of different morphologies on the efficiency and retention properties was investigated using pressure-assisted CEC (p-CEC), CEC, and low pressure-assisted liquid chromatography modes (LPLC). Baseline separation of the model analytes was respectively achieved including thiourea, toluene, naphthalene, and biphenyl with the lowest theoretical height up to 8.0 microm for thiourea in the mode of p-CEC. Furthermore, the influence of the tri-porogenic solvents on the morphology of methacrylate-based monoliths was systematically studied with mercury intrusion porosimetry and scanning electron microscopy. PMID:20515536

  20. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    SciTech Connect

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-28

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance ({sup 1}HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in {sup 1}HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF{sub 3}SO{sub 3} show the highest conductivity. The complexation between EMG30 and LiCF{sub 3}SO{sub 3} were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR)

  1. Unbiased phosphoproteomic method identifies the initial effects of a methacrylic acid copolymer on macrophages.

    PubMed

    Chamberlain, Michael Dean; Wells, Laura A; Lisovsky, Alexandra; Guo, Hongbo; Isserlin, Ruth; Talior-Volodarsky, Ilana; Mahou, Redouan; Emili, Andrew; Sefton, Michael V

    2015-08-25

    An unbiased phosphoproteomic method was used to identify biomaterial-associated changes in the phosphorylation patterns of macrophage-like cells. The phosphorylation differences between differentiated THP1 (dTHP1) cells treated for 10, 20, or 30 min with a vascular regenerative methacrylic acid (MAA) copolymer or a control methyl methacrylate (MM) copolymer were determined by MS. There were 1,470 peptides (corresponding to 729 proteins) that were differentially phosphorylated in dTHP1 cells treated with the two materials with a greater cellular response to MAA treatment. In addition to identifying pathways (such as integrin signaling and cytoskeletal arrangement) that are well known to change with cell-material interaction, previously unidentified pathways, such as apoptosis and mRNA splicing, were also discovered. PMID:26261332

  2. Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

    PubMed Central

    Gong, Shi-qiang; Niu, Li-na; Kemp, Lisa K.; Yiu, Cynthia K.Y.; Ryou, Heonjune; Qi, Yi-pin; Blizzard, John D.; Nikonov, Sergey; Brackett, Martha G.; Messer, Regina L.W.; Wu, Christine D.; Mao, Jing; Brister, L. Bryan; Rueggeberg, Frederick A.; Arola, Dwayne D.; Pashley, David H.; Tay, Franklin R.

    2012-01-01

    Design of antimicrobial polymers for enhancing healthcare issues and minimizing environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially-hydrolyzed QAMS copolymerized with bis-GMA is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. Kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix. PMID:22659173

  3. Rehabilitation of orbital cavity after orbital exenteration using polymethyl methacrylate orbital prosthesis.

    PubMed

    Jain, Sumeet; Jain, Parul

    2016-01-01

    Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events. PMID:27134437

  4. Experimental and theoretical investigation of the complexation of methacrylic acid and diisopropyl urea.

    PubMed

    Pogány, Peter; Razali, Mayamin; Szekely, Gyorgy

    2017-01-01

    The present paper explores the complexation ability of methacrylic acid which is one of the most abundant functional monomer for the preparation of molecularly imprinted polymers. Host-guest interactions and the mechanism of complex formation between methacrylic acid and potentially genotoxic 1,3-diisopropylurea were investigated in the pre-polymerization solution featuring both experimental (NMR, IR) and in silico density functional theory (DFT) tools. The continuous variation method revealed the presence of higher-order complexes and the appearance of self-association which were both taken into account during the determination of the association constants. The quantum chemical calculations - performed at B3LYP 6-311++G(d,p) level with basis set superposition error (BSSE) corrections - are in agreement with the experimental observations, reaffirming the association constants and justifying the validity of computational investigation of such systems. Furthermore, natural bond orbital analysis was carried out to appraise the binding properties of the complexes. PMID:27419640

  5. Synthesis and characterization of hydrolysed starch-g-poly(methacrylic acid) composite.

    PubMed

    Zahran, Magdy K; Ahmed, Enas M; El-Rafie, Mohamed H

    2016-06-01

    A novel method for the synthesis of starch-g-poly(methacrylic acid) composite was adopted by graft polymerization of hydrolysed starch (HS) and methacrylic acid (MAA) in aqueous medium using an efficient sodium perborate (SPB)-thiourea (TU) redox initiation system. The parameters influencing the redox system efficiency and thence the polymerization method were considered. These parameters comprehended the concentrations of MAA, SPB, TU and SPB/TU molar ratio as well as the polymerization temperature. The polymerization reaction was scrutinized through calculation of the MAA total conversion percent (TC%). The resultant poly(MAA-HS) composite was assessed by evaluating the polymer criteria (the graft yield, GY%; the grafting efficiency, GE%; the homopolymer, HP%; and the total conversion). The comportment of the apparent viscosity of the cooked poly(MAA)-starch composite paste, obtained under diverse polymerization conditions, was examined. Tentative mechanisms, which depict all occasions that happen amid the entire course of the polymerization reaction, have been proffered. PMID:26968925

  6. Effect of epoxidation on 30% poly(methyl methacrylate)-grafted natural rubber polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Nazir, Khuzaimah; Aziz, Ahmad Fairoz; Adam, Nurul Ilham; Yahya, Muhd Zu Azhan; Ali, Ab Malik Marwan

    2015-08-01

    Epoxidized 30% poly(methyl methacrylate)-grafted natural rubber (EMG 30) as a polymer host in solid polymer electrolytes (SPEs) has been investigated. EMG30 was synthesized via performicepoxidation method onto 30% poly(methyl methacrylate)-grafted natural rubber (MG30) and the formations of epoxy group were discussed. The EMG30 were characterized by proton nuclear magnetic resonance (1HNMR) to investigate their chemical structure and differential scanning calorimeter to determine their crystallinity. A new peak in 1HNMR spectra (2.71 ppm) confirmed the appearance of epoxy group. SPE based on EMG30 doped with 40 wt% LiCF3SO3 show the highest conductivity. The complexation between EMG30 and LiCF3SO3 were confirmed by attenuated total reflection Fourier transform infrared (ATR-FTIR).

  7. Surface-initiated Polymerization of Azidopropyl Methacrylate and its Film Elaboration via Click Chemistry

    PubMed Central

    Saha, Sampa; Bruening, Merlin L.; Baker, Gregory L.

    2013-01-01

    Azidopropyl methacrylate (AzPMA), a functional monomer with a pendent azido group, polymerizes from surfaces and provides polymer brushes amenable to subsequent elaboration via click chemistry. In DMF at 50 °C, click reactions between poly(AzPMA) brushes and an alkynylated dye proceed with >90% conversion in a few minutes. However, in aqueous solutions, reaction with an alkyne-containing poly(ethylene glycol) methyl ether (mPEG, Mn=5000) gives <10% conversion after a 12-h reaction at room temperature. Formation of copolymers with AzPMA and polyethylene glycol methyl ether methacrylate (mPEGMA) enables control over the hydrophilicity and functional group density in the copolymer to increase the yield of aqueous click reactions. The copolymers show reaction efficiencies as high as 60%. These studies suggest that for aqueous applications such as bioconjugation via click chemistry, control over brush hydrophilicity is vital. PMID:24293702

  8. Unbiased phosphoproteomic method identifies the initial effects of a methacrylic acid copolymer on macrophages

    PubMed Central

    Chamberlain, Michael Dean; Wells, Laura A.; Lisovsky, Alexandra; Guo, Hongbo; Isserlin, Ruth; Talior-Volodarsky, Ilana; Mahou, Redouan; Emili, Andrew; Sefton, Michael V.

    2015-01-01

    An unbiased phosphoproteomic method was used to identify biomaterial-associated changes in the phosphorylation patterns of macrophage-like cells. The phosphorylation differences between differentiated THP1 (dTHP1) cells treated for 10, 20, or 30 min with a vascular regenerative methacrylic acid (MAA) copolymer or a control methyl methacrylate (MM) copolymer were determined by MS. There were 1,470 peptides (corresponding to 729 proteins) that were differentially phosphorylated in dTHP1 cells treated with the two materials with a greater cellular response to MAA treatment. In addition to identifying pathways (such as integrin signaling and cytoskeletal arrangement) that are well known to change with cell–material interaction, previously unidentified pathways, such as apoptosis and mRNA splicing, were also discovered. PMID:26261332

  9. Preparation of well-defined poly(2-hydroxyethyl methacrylate) macromonomers via atom transfer radical polymerization.

    PubMed

    Yang, Pengcheng; Armes, Steven P

    2014-01-01

    A series of six near-monodisperse methacrylic macromonomers is prepared via atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate using a tertiary amine-functionalized initiator at 50 °C, followed by quaternization with excess 4-vinylbenzyl chloride at 20 °C. GPC analyses indicate polydispersities of around 1.20 and their mean degrees of polymerization (DP) range from 20 to 70, as judged by both (1) H NMR and UV spectroscopy. The former technique is more convenient but the latter proved more accurate for the higher DP values, provided that an appropriate model compound is utilized for calibration. Finally, these new macromonomers are used to prepare sterically stabilized polystyrene latexes with relatively narrow size distributions via alcoholic dispersion polymerization. PMID:24123461

  10. Preparation of silver-poly(acrylamide-co-methacrylic acid) composite microspheres with patterned surface structures.

    PubMed

    Xia, Huiyun; Zhang, Ying; Peng, Junxia; Fang, Yu; Gu, Zhongze

    2006-01-01

    Acrylamide (AM) and methacrylic acid (MAA) copolymer microgels were prepared by a reverse suspension polymerization technique. The microgels were used as templates for the preparation of silver-poly(acrylamide-co-methacrylic acid) [Ag-P(AM-co-MAA)] composite microspheres. The surface structures of the microspheres prepared in this way are characterized by zigzag-like structures. It was found that the composition of the microgels, the nature and dosage of surfactants, the quantity of the metal, and even the reduction methods employed have a significant effect upon the surface structures of the microspheres. X-ray diffraction analysis confirmed that Ag formed during the process is in a crystal state of a face-centered cubic structure. PMID:24058232

  11. Poly(glycidyl methacrylate)-A soft template for the facile preparation of poly(glycidyl methacrylate) core-copper nanoparticle shell nanocomposite

    NASA Astrophysics Data System (ADS)

    Mohammed Safiullah, S.; Abdul Wasi, K.; Anver Basha, K.

    2015-12-01

    Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) was prepared by simple two step method (i) The synthesis of poly(glycidyl methacrylate) (PGMA) beads by free radical suspension polymerization followed by (ii) direct deposition of copper nanoparticles (CuNPs) on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. In this method the CuNPs were formed by chemical reduction of copper salts using sodium borohydride in water medium and deposited directly on the activated PGMA. Two different concentrations of copper salts were employed to know the effect of concentration on the shape and size of nanoparticles. The results showed that, the different sizes and shapes of CuNPs were deposited on the PGMA matrix. The X-ray Diffraction study results showed that the CuNPs were embedded on the surface of the PGMA matrix. The scanning electron microscopic images revealed that the fabrication of CuNPs on the PGMA matrix possess different shapes and changes the morphology and nature of PGMA beads significantly. The fluorescent micrograph also confirmed that the CuNPs were doped on the PGMA surface. The thermal studies have demonstrated that the CuNPs deposition on the surface of PGMA beads had a significant effect.

  12. Nonviral Plasmid DNA Carriers Based on N,N'-Dimethylaminoethyl Methacrylate and Di(ethylene glycol) Methyl Ether Methacrylate Star Copolymers.

    PubMed

    Mendrek, Barbara; Sieroń, Łukasz; Żymełka-Miara, Iwona; Binkiewicz, Paulina; Libera, Marcin; Smet, Mario; Trzebicka, Barbara; Sieroń, Aleksander L; Kowalczuk, Agnieszka; Dworak, Andrzej

    2015-10-12

    Star polymers with random and block copolymer arms made of cationic N,N'-dimethylaminoethyl methacrylate (DMAEMA) and nonionic di(ethylene glycol) methyl ether methacrylate (DEGMA) were synthesized via atom transfer radical polymerization (ATRP) and used for the delivery of plasmid DNA in gene therapy. All stars were able to form polyplexes with plasmid DNA. The structure and size of the polyplexes were precisely determined using light scattering and cryo-TEM microscopy. The hydrodynamic radius of a complex of DNA with star was dependent on the architecture of the star arms, the DEGMA content and the number of amino groups in the star compared to the number of phosphate groups of the nucleic acid (N/P ratio). The smallest polyplexes (Rh90°∼50 nm) with positive zeta potentials (∼15 mV) were formed of stars with N/P=6. The introduction of DEGMA into the star structure caused a decrease of polyplex cytotoxicity in comparison to DMAEMA homopolymer stars. The overall transfection efficiency using HT-1080 cells showed that the studied systems are prospective gene delivery agents. The most promising results were obtained for stars with random copolymer arms of high DEGMA content. PMID:26375579

  13. NMR Characterization of Segmental Dynamics in Glassy Poly(alkyl methacrylate)s Using Centerband-Only Detection of Exchange (CODEX)

    NASA Astrophysics Data System (ADS)

    Bonagamba, Tito J.; Becker-Guedes, Fabio; Deazevedo, Eduardo R.; Hu, Weiguo; Schmidt-Rohr, Klaus

    2000-03-01

    We will present applications of a new solid-state NMR technique, CODEX, for detecting slow (0.1/s to 3000/s) segmental reorientations with the highest achievable sensitivity and site resolution, under fast magic-angle spinning (MAS) conditions. The chemical-shift anisotropy is recoupled before and after a mixing time by a sequence of rotor-synchronized 180^o radio-frequency pulses. Segmental reorientations during the mixing time result in frequency changes that dephase the magnetization and thus decrease the mobile-site signal. The correlation function is traced out by the mixing-time dependence of the intensity, while the motional amplitude can be estimated from the recoupling-time dependence. The fraction of mobile groups and the number of orientational sites is obtained from the long-time asymptotic intensity, in combination with four-time CODEX. A detailed CODEX-based characterization of the segmental dynamics associated with the beta-relaxation in glassy poly(alkyl methacrylate)s will be presented. We have quantified the fraction of flipping sidegroups as a function of the sidegroup size and characterized the slow backbone motions that are also observed.

  14. Preparation and characterization of pH-sensitive and antifouling poly(vinylidene fluoride) microfiltration membranes blended with poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid).

    PubMed

    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. PMID:25203908

  15. Photophysical, photochemical and laser behavior of some diolefinic laser dyes in sol-gel and methyl methacrylate/2-hydroxyethyl methacrylate copolymer matrices

    NASA Astrophysics Data System (ADS)

    Sakr, Mahmoud A. S.; Abdel Gawad, El-Sayed A.; Abou Kana, Maram T. H.; Ebeid, El-Zeiny M.

    2015-08-01

    The photophysical properties such as singlet absorption, molar absorptivity, fluorescence spectra, dipole moment, fluorescence quantum yields, fluorescence lifetimes and laser activity of 1,4-bis (β-Pyridyl-2-Vinyl) Benzene (P2VB), 2,5-distyryl-pyrazine (DSP) and 1,4-bis(2-methylstyryl)benzene(MSB) diolefineic laser dyes have been measured in different restricted hosts. (P2VB), (DSP) and (MSB) are embedded in transparent sol-gel glass and a copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) media. The absorption and fluorescence properties of these laser dyes in sol-gel glass matrices are compared with their respective properties in copolymer host. The photostability of these laser dyes in sol-gel glass and (MMA/HEMA) copolymer samples are measured in terms of half-life method (using nitrogen laser 337.1 nm in pumping), as the number of pulses necessary to reduce the dye laser intensity to 50% of its original value. The gel laser materials show improved photostability upon pumping by nitrogen laser compared with those in organic polymeric host matrix.

  16. Microleakage of silorane- and methacrylate-based class V composite restorations.

    PubMed

    Krifka, Stephanie; Federlin, Marianne; Hiller, Karl-Anton; Schmalz, Gottfried

    2012-08-01

    The marginal integrity of class V restorations in a silorane- and a group of methacrylate-based composite resins with varying viscosities was tested in the present study. Different adhesives (OptiBond FL, KerrHawe; AdheSE One, Vivadent; or Silorane System Adhesive, 3M ESPE) were applied to 168 standardized class V cavities. The cavities (n = 12) were filled with a wide range of different viscous composite resins: Filtek Silorane, 3M ESPE; els and els flow, Saremco; Tetric EvoCeram and Tetric EvoFlow, Vivadent; Grandio, Voco; and Ultraseal XT Plus, Ultradent. Microleakage of the restoration was assessed by dye penetration (silver staining) on multiple sections with and without thermocycling and mechanical loading (TCML: 5,000 × 5-55°C; 30 s/cycle; 500,000 × 72.5 N, 1.6 Hz). Data were statistically analyzed with the Mann-Whitney U test and the Error Rates Method (ERM). The silorane-based composite resin yielded the lowest dye penetration after TCML. Microleakage of methacrylate-based composite restorations, in general (ERM), was statistically significantly influenced by the adhesive system, Moreover, dye penetration at enamel margins was significantly lower than dye penetration at dentin margins. The chemical basis of composite resins and adjacent tooth substance seems to strongly influence marginal sealing of class V restorations for methacrylate-based materials. Moreover, the steps of dental adhesives used affected marginal integrity. The silorane-based composite resin evaluated in the present study exhibits the best marginal seal. The three-step adhesive yielded better marginal sealing than the one-step adhesive for methacrylate-based class V composite restorations. PMID:21947906

  17. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Technology (Revised) (Presentation)

    SciTech Connect

    Miller, D. C.; Carloni, J. D.; Pankow, J. W.; Gjersing, E. L.; To, B.; Packard, C. E.; Kennedy, C. E.; Kurtz, S. R.

    2012-01-01

    Concentrating photovoltaic (CPV) technology recently gained interest based on its expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems employ Fresnel lenses composed of poly(methyl methacrylate) (PMMA) to obtain a high optical flux density on the cell. The optical and mechanical durability of these lenses, however, is not well established relative to the desired surface life of 30 years. Our research aims to quantify the expected lifetime of PMMA in key market locations (FL, AZ, and CO).

  18. Surgical treatment of frontal sinus fracture sequelae with methyl methacrylate prosthesis

    PubMed Central

    Cavalieri-Pereira, Lucas; Assis, Adriano; Olate, Sergio; Asprino, Luciana; de Moraes, Marcio

    2013-01-01

    Inappropriate treatment of fractures of the frontal sinus can lead to serious complications. These fractures are often associated with soft tissue injuries and loss of bony structures. This case report shows the use of methyl methacrylate frontal prosthesis to treat a sequel of frontal sinus fracture; surgical options are discusses and one-year follow-up is present to show stability and good cosmetic result. PMID:24273699

  19. Dye-sensitized solar cell comprising polyethyl methacrylate doped with ammonium iodide solid polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Singh, Vivek Kr.; Bhattacharya, B.; Shukla, S.; Singh, Pramod K.

    2014-09-01

    The aim of the present work was to develop a new solid electrolyte polyethyl methacrylate doped with ammonium iodide polymer electrolyte and its application in dye-sensitized solar cell (DSSC). The electrical, structural and photoelectrochemical properties of polymer electrolytes are presented in detail. DSSCs have been fabricated and characterized. The polymer electrolyte film with maximum ionic conductivity shows maximum efficient DSSC of efficiency 0.43 % at 1 sun condition.

  20. Dye-sensitized solar cell comprising polyethyl methacrylate doped with ammonium iodide solid polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Singh, Vivek Kr.; Bhattacharya, B.; Shukla, S.; Singh, Pramod K.

    2015-03-01

    The aim of the present work was to develop a new solid electrolyte polyethyl methacrylate doped with ammonium iodide polymer electrolyte and its application in dye-sensitized solar cell (DSSC). The electrical, structural and photoelectrochemical properties of polymer electrolytes are presented in detail. DSSCs have been fabricated and characterized. The polymer electrolyte film with maximum ionic conductivity shows maximum efficient DSSC of efficiency 0.43 % at 1 sun condition.