Ethyl Acrylate (ethyl + acrylate)

Distribution by Scientific Domains


Selected Abstracts


Compositional and configurational sequence determination of methyl methacrylate/ethyl acrylate copolymers by one- and two-dimensional nuclear magnetic resonance spectroscopy

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2003
A. S. Brar
Abstract Ethyl acrylate (E)/methyl methacrylate (M) copolymers of different compositions were prepared, and their compositions were determined with 1H NMR spectra. The complete spectral assignments, in terms of the compositional and configurational sequences of these copolymers, were made with the help of distortionless enhancement by polarization transfer and two-dimensional heteronuclear single quantum coherence spectroscopy. The ,-(CH3)M, CH (E), CH2, and ,CO carbons of both M and E units were found to be sensitive to various compositional and configurational sequences. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 313,326, 2003 [source]


High temperature copolymerization of styrene/ethyl acrylate: Reactivity ratio estimation in bulk and solution

ADVANCES IN POLYMER TECHNOLOGY, Issue 3 2004
Nahla Sahloul
Abstract Styrene/ethyl acrylate (Sty/EA) free-radical copolymerizations have been conducted in bulk with and without initiator and in solution using p -xylene and m -xylene (30 wt% and 60 wt% solvent level) at 100°C and 130°C. The monomer reactivity ratio values and their temperature dependence have been determined from low conversion copolymer composition data using the computer software package RREVM, which is based on the error in variables model (EVM) method. Copolymer composition data at low conversion confirmed the Mayo,Lewis model at both temperatures. The reactivity ratio values of the Sty/EA system do not seem to change with dilution by nonpolar solvents at low concentration from the reactivity ratio values obtained in bulk with and without initiator. However, xylene isomers were found to have a slight effect on the reactivity ratio value of ethyl acrylate when high solvent concentration was utilized. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 186,195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20009 [source]


CEC separation of heterocyclic amines using methacrylate monolithic columns

ELECTROPHORESIS, Issue 11 2007
Elena Barceló-Barrachina
Abstract Two methacrylate-based monolithic columns, one with a negatively charged group (sulfonic group) and another with a new monomer N,N -dimethylamino ethyl acrylate (DMAEA), were prepared and tested for the separation of basic compounds by CEC. This new monolithic stationary phase was prepared by the in situ polymerization of DMAEA with butyl methacrylate and ethylene dimethacrylate, using a ternary porogenic solvent consisting of water, 1-propanol and 1,4-butanediol. The performance of this column was evaluated by means of the analysis of a family of heterocyclic amines. Separation conditions such as pH, amount of organic modifier, ionic strength and elution mode (normal or counterdirectional flow) were studied. At the optimal running electrolyte composition, and using the counterdirectional mode, symmetrical electrochromatographic peaks were obtained, with the number of theoretical plates up to 30,000 and a good resolution between closely related peaks. The 2-acrylamido-2-methyl-1-propane-sulfonic acid column was used for CEC-MS, taking advantage of the compatibility of its elution mode (normal flow) with the MS coupling. [source]


Straightforward Strategy for the Stereoselective Synthesis of Spiro-Fused (C-5)Isoxazolino- or (C-3)Pyrazolino-(C-3)quinolin-2-ones from Baylis,Hillman Adducts by 1,3-Dipolar Cycloaddition and Reductive Cyclization,

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 32 2008
Virender Singh
Abstract A straightforward and general approach for the stereoselective synthesis of spiro-fused (C-5)isoxazolino- or (C-3)pyrazolino-(C-3)quinolin-2-ones from the adducts offorded from the Baylis,Hillman reaction of 2-nitrobenzaldehyde and ethyl acrylate by sequential 1,3-dipolar cycloaddition and reductive cyclization is presented. It was found that the reductive cyclization of the isoxazoline derivatives proceeded efficiently in the presence of In/HCl, whereas similar reductions of pyrazolines gave better yields when carried out in the presence of an Fe/AcOH mixture. However, similar attempts employing the Baylis,Hillman adduct of 2-nitrobenzaldehyde and methyl vinyl ketone did not yield the desired compounds.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


Synthesis of Monosaccharide-Derived Spirocyclic Cyclopropylamines and Their Evaluation as Glycosidase Inhibitors

HELVETICA CHIMICA ACTA, Issue 9 2003
Christian Blüchel
The glucose-, mannose-, and galactose-derived spirocyclic cyclopropylammonium chlorides 1a,1d, 2a,2d and 3a,3d were prepared as potential glycosidase inhibitors. Cyclopropanation of the diazirine 5 with ethyl acrylate led in 71% yield to a 4,:,5,:,1,:,20 mixture of the ethyl cyclopropanecarboxylates 7a,7d, while the Cu-catalysed cycloaddition of ethyl diazoacetate to the exo -glycal 6 afforded 7a,7d (6,:,2,:,5,:,3) in 93,98% yield (Scheme,1). Saponification, Curtius degradation, and subsequent addition of BnOH or t- BuOH led in 60,80% overall yield to the Z- or Boc-carbamates 11a,11d and 12a,12d, respectively. Hydrogenolysis of 11a,11d afforded 1a,1d, while 12a,12d was debenzylated to 13a,13d prior to acidic cleavage of the N -Boc group. The manno - and galacto -isomers 2a,2d and 3a,3d, respectively, were similarly obtained in comparable yields (Schemes,2 and 4). Also prepared were the differentially protected manno- configured esters 24a,24d; they are intermediates for the synthesis of analogous N -acetylglucosamine-derived cyclopropanes (Scheme,3). The cyclopropylammonium chlorides 1a,1d, 2a,2d and 3a,3d are very weak inhibitors of several glycosidases (Tables,1 and 2). Traces of Pd compounds, however, generated upon catalytic debenzylation, proved to be strong inhibitors. PdCl is, indeed, a reversible, micromolar inhibitor for the ,- glucosidases from C. saccharolyticum and sweet almonds (non-competitive), the , -galactosidases from bovine liver and from E. coli (both non-competitive), the , -galactosidase from Aspergillus niger (competitive), and an irreversible inhibitor of the , -glucosidase from yeast and the , -galactosidase from coffee beans. The cyclopropylamines derived from 1a,1d or 3a,3d significantly enhance the inhibition of the ,- glucosidase from C. saccharolyticum by PdCl, lowering the Ki value from 40,,M (PdCl) to 0.5,,M for a 1,:,1 mixture of PdCl and 1d. A similar effect is shown by cyclopropylamine, but not by several other amines. [source]


Synthesis of Scopin Acetate and 6,7-Didehydrohyoscyamin.

HELVETICA CHIMICA ACTA, Issue 9 2003
Intramolecular Phenylsulfenylation of a Nonactivated Methylene Group of Ethyl N -Demethyl-3- O -(phenylthio)tropine- N -carboxylate
The synthesis of scopin acetate (6b) and 6,7-didehydrohyoscyamine (17) was achieved by using tropine (5) as the starting compound. Formal (phenylthio)-radical transfer to the nonactivated 6-position of ethyl N -demethyl-3- O -(phenylthio)tropine- N -carboxylate (9) by irradiation in the presence of hexabutyldistannane is a key step of this synthetic approach, involving ethyl 6,7-didehydro- N -demethyltropine- N -carboxylate (15) as a synthetic intermediate (Schemes,3 and 5). The reaction of 9 with tributylstannane in the presence of ethyl acrylate, as a radicophilic olefin, involves Michael -type alkylation at C(6) of the tropine skeleton affording ethyl N -demethyl- N -(ethoxycarbonyl)tropine-6-propanoate (18) (Scheme,6). [source]


Silica-Supported Zirconium Complexes and their Polyoligosilsesquioxane Analogues in the Transesterification of Acrylates: Part 2.

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009
Activity, Recycling, Regeneration
Abstract The catalytic activity of both supported and soluble molecular zirconium complexes was studied in the transesterification reaction of ethyl acrylate by butanol. Two series of catalysts were employed: three well defined silica-supported acetylacetonate and n -butoxy zirconium(IV) complexes linked to the surface by one or three siloxane bonds, (SiO)Zr(acac)3 (1) (SiO)3Zr(acac) (2) and (SiO)3Zr(O- n -Bu) (3), and their soluble polyoligosilsesquioxy analogues (c -C5H9)7Si8O12(CH3)2Zr(acac)3 (1,), (c -C5H9)7Si7O12Zr(acac) (2,), and (c -C5H9)7Si7O12Zr(O- n -Bu) (3,). The reactivity of these complexes were compared to relevant molecular catalysts [zirconium tetraacetylacetonate, Zr(acac)4 and zirconium tetra- n -butoxide, Zr(O- n- Bu)4]. Strong activity relationships between the silica-supported complexes and their polyoligosilsesquioxane analogues were established. Acetylacetonate complexes were found to be far superior to alkoxide complexes. The monopodal complexes 1 and 1, were found to be the most active in their respective series. Studies on the recycling of the heterogeneous catalysts showed significant degradation of activity for the acetylacetonate complexes (1 and 2) but not for the less active tripodal alkoxide catalyst, 3. Two factors are thought to contribute to the deactivation of catalyst: the lixivation of zirconium by cleavage of surface siloxide bonds and exchange reactions between acetylacetonate ligands and alcohols in the substrate/product solution. It was shown that the addition of acetylacetone to the low activity catalyst Zr(O- n- Bu)4 produced a system that was as active as Zr(acac)4. The applicability of ligand addition to heterogeneous systems was then studied. The addition of acetylacetone to the low activity solid catalyst 3 produced a highly active catalyst and the addition of a stoichiometric quantity of acetylacetone at each successive batch catalytic run greatly reduced catalyst deactivation for the highly active catalyst 1. [source]


High temperature copolymerization of styrene/ethyl acrylate: Reactivity ratio estimation in bulk and solution

ADVANCES IN POLYMER TECHNOLOGY, Issue 3 2004
Nahla Sahloul
Abstract Styrene/ethyl acrylate (Sty/EA) free-radical copolymerizations have been conducted in bulk with and without initiator and in solution using p -xylene and m -xylene (30 wt% and 60 wt% solvent level) at 100°C and 130°C. The monomer reactivity ratio values and their temperature dependence have been determined from low conversion copolymer composition data using the computer software package RREVM, which is based on the error in variables model (EVM) method. Copolymer composition data at low conversion confirmed the Mayo,Lewis model at both temperatures. The reactivity ratio values of the Sty/EA system do not seem to change with dilution by nonpolar solvents at low concentration from the reactivity ratio values obtained in bulk with and without initiator. However, xylene isomers were found to have a slight effect on the reactivity ratio value of ethyl acrylate when high solvent concentration was utilized. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 186,195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20009 [source]


Synthesis of hyperbranched degradable polymers by atom transfer radical (Co)polymerization of inimers with ester or disulfide groups

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2009
Nicolay V. Tsarevsky
Abstract Degradable hyperbranched polymers with multiple alkyl halide chain ends were synthesized by the atom transfer radical polymerization of inimers containing ester (2-(2,-bromopropionyloxy)ethyl acrylate) or disulfide (2-(2,-bromoisobutyryloxy)ethyl 2,,-methacryloyloxyethyl disulfide) groups. Both the homo- and copolymerizations (with styrene in the former case and methyl methacrylate in the latter) were studied. The hyperbranched polymers derived from the ester-type inimer were hydrolytically degradable under basic conditions, whereas those derived from the disulfide-containing inimer could be efficiently degraded in the presence of reducing agents such as tributylphosphine. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009 [source]


Synthesis of perfectly bifunctional polyacrylates by single-electron-transfer living radical polymerization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2007
Gerard Lligadas
Abstract Poly(methyl acrylate)s, poly(ethyl acrylate)s, and poly(butyl acrylate)s with ,,,-di(bromo) chain ends and Mn from 8500 to 35,000 were synthesized by single-electron-transfer living radical polymerization (SET-LRP). The analysis of their chain ends by a combination of 1H and 2D-NMR, GPC, MALDI-TOF MS, chain end functionalization, chain extension, and halogen exchange experiments demonstrated the synthesis of perfectly bifunctional polyacrylates by SET-LRP. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4684,4695, 2007 [source]


Synthesis of diblock copolymers by combining stable free radical polymerization and atom transfer radical polymerization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2006
Yan Shi
Abstract A stable nitroxyl radical functionalized with an initiating group for atom transfer radical polymerization (ATRP), 4-(2-bromo-2-methylpropionyloxy)-2,2,6,6-tetramethyl-1-piperidinyloxy (Br-TEMPO), was synthesized by the reaction of 4-hydroxyl-2,2,6,6-tetramethyl-1-piperidinyloxy with 2-bromo-2-methylpropionyl bromide. Stable free radical polymerization of styrene was then carried out using a conventional thermal initiator, dibenzoyl peroxide, along with Br-TEMPO. The obtained polystyrene had an active bromine atom for ATRP at the ,-end of the chain and was used as the macroinitiator for ATRP of methyl acrylate and ethyl acrylate to prepare block copolymers. The molecular weights of the resulting block copolymers at different monomer conversions shifted to higher molecular weights and increased with monomer conversion. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2468,2475, 2006 [source]


Synthesis of an alkali-swellable emulsion and its effect on the rate of polymer diffusion in poly(vinyl acetate-butyl acrylate) latex films

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2005
Jung Kwon Oh
Abstract We describe the synthesis and characterization of a weakly cross-linked poly(methacrylic acid- co -ethyl acrylate) alkali-swellable emulsion (ASE), as well as an investigation of its influence on the rate of polymer diffusion in latex films. The films examined were formed from poly(vinyl acetate- co -butyl acrylate) latex particles containing a small amount of acrylic acid as a comonomer. Polymer diffusion rates were monitored by the energy transfer technique. We found that the presence of the ASE component, either in the acid form or fully neutralized by ammonia or sodium hydroxide, had very little effect on the polymer diffusion rate. However, in the presence of 2 wt % NH4 -ASE, there was a small but significant increase in the polymer diffusion rate. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5632,5642, 2005 [source]


Microparticles of poly(methacrylic acid),gadolinium ion complex and their magnetic force microscopic images

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2004
Tsuyoshi Michinobu
Abstract Modified poly(methacrylic acid) microparticles complexed with gadolinium(III) (Gd3+) ions were prepared in 100 nm. The emulsion terpolymerization of methacrylic acid, ethyl acrylate, and allyl methacrylate and the following complexation with Gd3+ ions yielded the polymer particles with different Gd3+ ion contents. Potentiometric titration of the complexation of the particle with Gd3+ ions indicated the formation of a very stable tris-carboxylate coordinate complex with the Gd3+ ion. Electron spin resonance and IR spectra of the complexed particles were dependent on the Gd3+ ion content and the coordination environment in each particle. The microparticles dispersed on a mica substrate were subjected to atomic force microscopy (AFM), followed by magnetic force microscopy (MFM). AFM showed 100-nm-sized and monodispersed spherical images. The following MFM clearly provided strong magnetic responses exactly on the same particle positions, of which the images were also dependent on the Gd3+ ion content in the particle. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1912,1918, 2004 [source]


Preparation and characterization of poly(ethyl acrylate)/bentonite nanocomposites by in situ emulsion polymerization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 11 2002
Xin Tong
Abstract Transparent poly(ethyl acrylate) (PEA)/bentonite nanocomposites containing intercalated,exfoliated combinatory structures of clay were synthesized by in situ emulsion polymerizations in aqueous dispersions containing bentonite. The samples for characterization were prepared through direct-forming films of the resulting emulsions without coagulation and separation. An examination with X-ray diffraction and transmission electron microscopy showed that intercalated and exfoliated structures of clay coexisted in the PEA/bentonite nanocomposites. The measurements of mechanical properties showed that PEA properties were greatly improved, with the tensile strength and modulus increasing from 0.65 and 0.24 to 11.16 and 88.41 MPa, respectively. Dynamic mechanical analysis revealed a very marked improvement of the storage modulus above the glass-transition temperature. In addition, because of the uniform dispersion of silicate layers in the PEA matrix, the barrier properties of the materials were dramatically improved. The permeability coefficient of water vapor decreased from 30.8 × 10,6 to 8.3 × 10,6 g cm/cm2 s cmHg. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1706,1711, 2002 [source]


Synthesis of poly[(2-oxo-1,3-dioxolane-4-yl) methyl methacrylate- co -ethyl acrylate] by incorporation of carbon dioxide into epoxide polymer and the miscibility behavior of its blends with poly(methyl methacrylate) or poly(vinyl chloride)

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2001
Sung-Young Park
Abstract This study was related to the investigation of the chemical fixation of carbon dioxide to a copolymer bearing epoxide and the application of the cyclic carbonate group containing copolymer-to-polymer blends. In the synthesis of poly[(2-oxo-1,3-dioxolane-4-yl) methyl methacrylate- co -ethyl acrylate] [poly(DOMA- co -EA)] from poly(glycidyl methacrylate- co -ethyl acrylate) [poly(GMA- co -EA)] and CO2, quaternary ammonium salts showed good catalytic activity. The films of poly(DOMA- co -EA) with poly(methyl methacrylate) (PMMA) or poly(vinyl chloride) (PVC) blends were cast from N,N,-dimethylformamide solution. The miscibility of the blends of poly(DOMA- co -EA) with PMMA or PVC have been investigated both by DSC and visual inspection of the blends. The optical clarity test and DSC analysis showed that poly(DOMA- co -EA) containing blends were miscible over the whole composition range. The miscibility behaviors were discussed in terms of Fourier transform infrared spectra and interaction parameters based on the binary interaction model. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1472,1480, 2001 [source]


Green Machining of a Thermoplastic Ceramic-Ethylene Ethyl Acrylate/Isobutyl Methacrylate Compound

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2004
Young-Hag Koh
The machinability of a thermoplastic compound that consisted of 52 vol% ceramic particles and 48 vol% thermoplastic binders was investigated. To investigate the machining mechanisms, various blends of a ductile polymer (ethylene ethyl acrylate (EEA)) and a brittle polymer (isobutyl methacrylate (IBMA)) were used as thermoplastic binders. The fraction of IBMA to EEA in the blend was increased from 0 to 50 vol%. As the IBMA content was increased, the thermoplastic compound exhibited a stiffer stress versus strain response under compression because of the brittle nature of the IBMA polymer. The machinability of the thermoplastic compound was remarkably improved with increased IBMA content because of the mitigation of the extensive deformation of the thermoplastic compound. [source]


Fibrinogen Patterns and Activity on Substrates with Tailored Hydroxy Density

MACROMOLECULAR BIOSCIENCE, Issue 8 2009
José Carlos Rodríguez Hernández
Abstract The influence of the surface fraction of OH groups on fibrinogen (FG) adsorption is investigated in copolymers of ethyl acrylate and hydroxy ethylacrylate. The amount of adsorbed FG, quantified by western-blotting combined with image analysis of the corresponding bands, decreases as the hydrophilicity of the substrate increases. The influence of substrate wettability on FG conformation and distribution is observed by atomic force microscopy (AFM). The most hydrophobic substrate promotes FG fibrillogenesis, which leads to a fibrin-like appearance in the absence of any thrombin. The degree of FG interconnection was quantified by calculating the fractal dimension of the adsorbed protein from image analysis of the AFM results. The biological activity of the adsorbed FG is correlated to cell adhesion on FG-coated substrates. [source]


The Properties of Covalently Immobilized Trypsin on Soap-Free P(MMA-EA-AA) Latex Particles

MACROMOLECULAR BIOSCIENCE, Issue 4 2005
Kai Kang
Abstract Summary: The covalent immobilization of trypsin onto poly[(methyl methacrylate)- co -(ethyl acrylate)- co -(acrylic acid)] latex particles, produced by a soap-free emulsion polymerization technique, was carried out using the carbodiimide method. The catalytic properties and kinetic parameters, as well as the stability of the immobilized enzyme were compared to those of the free enzyme. Results showed that the optimum temperature and pH for the immobilized trypsin in the hydrolysis of casein were 55,°C and 8.5, both of which were higher than that of the free form. It was found that Km (Michaelis constant) was 45.7 mg,·,ml,1 and Vmax (maximal reaction rate) was 793.0 ,g,·,min,1 for immobilized trypsin, compared to a Km of 30.0 mg,·,ml,1 and a Vmax of 5,467.5 ,g,·,min,1 for free trypsin. The immobilized trypsin exhibited much better thermal and chemical stabilities than its free counterpart and maintained over 63% of its initial activity after reusing ten times. TEM photograph of latex particles after trypsin immobilization. [source]


Reinforcement of liquid ethylene,propylene,dicyclopentadiene copolymer based elastomer with vinyl functionalized multiwalled carbon nanotubes

POLYMER ENGINEERING & SCIENCE, Issue 7 2010
Hongfu Zhou
A methodology for reinforcement of liquid ethylene,propylene,dicyclopentadiene copolymer (liquid-EPDM) based elastomer with multiwalled carbon nanotubes (MWCNTs) was proposed. Acid-treated MWCNTs were first reacted with poly(acryloyl chloride) (PACl) leading to a grafted encapsulation, which were subsequently reacted with hydroxy ethyl acrylate (HEA) to generate vinyl groups. Thus obtained vinyl groups functionalized MWCNTs (vinyl-MWCNTs) were characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, and thermogravimetric analysis. The vinyl-MWCNTs were blended with liquid-EPDM and subjected to co-curing; an intercrosslinked structure was obtained via the free radical polymerization among the vinyl groups on vinyl-MWCNTs and the double bonds on liquid-EPDM. As a result, the vinyl-MWCNTs and the cured EPDM matrix were covalently linked. The chemical interfacial interaction between vinyl-MWCNTs and the cured matrix were observed by scanning electron microscope, which provided obvious reinforcement of elastomer. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers [source]


Ceric(IV) ion-induced graft copolymerization of acrylamide and ethyl acrylate onto cellulose

POLYMER INTERNATIONAL, Issue 2 2006
Prof. Kailash C Gupta
Abstract Graft copolymerization of acrylamide (AAm) and ethyl acrylate (EA) onto cellulose has been carried out from their binary mixtures using ceric ammonium nitrate (CAN) as an initiator in the presence of nitric acid at 25 ± 1 °C. The extent of acrylamide grafting increased in the presence of the EA comonomer. The composition of the grafted chains (FAAm = 0.52) was found to be constant during the feed molarity variation from 7.5 × 10,2 to 60.0 × 10,2 mol L,1, whereas the composition of the grafted chains (FAAm) was found to be dependent on feed composition (fAAm) and reaction temperature. The effects of ceric(IV) ion concentration, reaction time and temperature on the grafting parameters have been studied. The grafting parameters showed an increasing trend up to 6.0 × 10,3 mol L,1 concentration of CAN at a feed molarity of 30.0 × 10,2 mol L,1 and showed a decreasing trend on further increasing the concentration of CAN (>6.0 × 10,3 mol L,1) at a constant concentration of nitric acid (5.0 × 10,2 mol L,1). The composition of the grafted chains (FAAm) was determined by IR spectroscopy and nitrogen content and the data obtained then used to determine the reactivity ratios of the acrylamide (r1) and ethyl acrylate (r2) comonomers by using a Mayo and Lewis plot. The reactivity ratios of acrylamide and ethyl acrylate were found to be r1 = 0.54 and r2 = 1.10, respectively, and hence the sequence lengths of acrylamide (m,M1) and ethyl acrylate (m,M2) in the grafted chains are arranged in an alternating form, as the product of the reactivity ratios of acrylamide and ethyl acrylate (r1 × r2) is less than unity. The rate of graft copolymerization of the comonomers onto cellulose was found to be dependant on the ,squares' of the concentrations of the comonomers and on the ,square root' of the concentration of ceric ammonium nitrate. The energy of activation (,Ea) of graft copolymerzation was found to be 5.57 kJ mol,1 within the temperature range from 15 to 50 °C. On the basis of the results, suitable reaction steps have been proposed for the graft copolymerzation of acrylamide and ethyl acrylate comonomers from their mixtures. Copyright © 2005 Society of Chemical Industry [source]


Viscoelastic properties of branched polyacrylate melts

POLYMER INTERNATIONAL, Issue 6 2001
Nasir M Ahmad
Abstract The viscoelastic properties of poly(n-butyl acrylate), poly(ethyl acrylate) and poly(methyl acrylate) melts have been studied using samples that varied in both molar mass and the mol% branched repeat units, these properties having been previously determined by gel permeation chromatography and 13C NMR spectroscopy, respectively. Poly(n-butyl acrylate) was studied most extensively using seven samples; one sample of poly(n-butyl acrylate), two samples of poly(ethyl acrylate) and one sample of poly(methyl acrylate) were used to study the effect of side-group size. Storage and loss moduli were measured over a range of frequency (1,×,10,3 to 1,×,102,rad,s,1) at temperatures from Tg,+,20,°C to Tg,+,155,°C and then shifted to form master curves at Tg,+,74,°C through use of standard superposition procedures. The plateau regions were not distinct due to the broad molar mass distributions of the polyacrylates. Hence, the upper and lower limits of shear storage modulus from the nominal ,plateau' region of the curves for the seven poly(n-butyl acrylate) samples were used to calculate the chain molar mass between entanglements, Me, which gave the range 13.0,kg,mol,1,<,Me,<,65.0,kg,mol,1. The Graessley,Edwards dimensionless interaction density and dimensionless contour length concentration were calculated for poly(n-butyl acrylate) using the mean value of plateau modulus (1.2,×,105,Pa) and three different methods for estimation of the Kuhn length; the data fitted closely to the Graessley,Edwards universal plot. The Williams,Landel,Ferry C1 and C2 parameters were determined for each of the polyacrylates; the data for the poly(n-butyl acrylate) samples indicate an overall reduction in C1 and C2 as the degree of branching increases. Although the values of C1 and C2 were different for poly(n-butyl acrylate), poly(ethyl acrylate) and poly(methyl acrylate), there is no trend for variation with structure. Thus the viscoelastic properties of the polyacrylate melts are similar to those for other polymer melts and, for the samples investigated, the effect of molar mass appears to dominate the effect of branching. © 2001 Society of Chemical Industry [source]


Aqueous polymerization of ethyl acrylate initiated by ceric ion-reducing agent systems in nitric acid medium

POLYMER INTERNATIONAL, Issue 3 2001
V Ramana Reddy
Abstract Kinetic study of aqueous polymerization of ethyl acrylate (EA) was carried out at 30,°C in dilute nitric acid medium by employing ammonium ceric nitrate (ACN),methyl cellosolve (MC) and ACN,ethyl cellosolve (EC) as redox initiator systems. The ceric ion consumption was found to be first order with respect to ceric ion concentration with both initiator systems. The formation of complexes between Ce(IV) and reducing agents (RA) was observed. The order with respect to Ce(IV), reducing agents and monomer was evaluated for aqueous polymerization of EA by Ce(IV),MC and Ce(IV),EC redox initiator systems. The overall activation energy, Eoverall, for aqueous polymerization of EA was evaluated in the temperature region of 27,40,°C with both initiator systems. A kinetic mechanism for aqueous polymerization of EA initiated by redox initiator systems is presented. © 2001 Society of Chemical Industry [source]


Short wavelength light reflecting films from side-chain liquid crystal homopolymers with chiral spacers

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2001
J. M. G. Cowie
Abstract A series of acrylate monomers with alkoxy tails of varying lengths are synthesised and polymerised. The butoxy analogue had a stable enantiotropic cholesteric liquid crystalline phase which formed a grandjean texture when prepared as a thin film between glass slides. The polymer was mixed with a low molar mass nematic liquid crystal in various proportions and the pitch of the chiral nematic phases were determined using a cano-wedge cell technique. The polymer prepared from (S)-2-(4-butoxyphenyl-4,-benzoyloxy)-1-methyl ethyl acrylate had a pitch length of 113,nm which indicates that the polymer film could be employed in optical devices requiring selective reflection of light with short wavelengths in the region of 170,nm. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Evidence for Spontaneous Release of Acrylates from a Transition-Metal Complex Upon Coupling Ethene or Propene with a Carboxylic Moiety or CO2

CHEMISTRY - A EUROPEAN JOURNAL, Issue 32 2007
Michele Aresta Prof.
Abstract The development of a new synthetic approach to acrylates based on the formation of alkyl esters of acrylic acids has been studied. A preformed Pd,COOMe moiety is used as a model system to investigate the insertion of an olefin into the PdC bond. The fast elimination of acrylate is observed. Density functional calculations support the experimental findings and allow the characterization of transition states along the reaction pathway. The first example of olefin/CO2 coupling with facile release of ethyl acrylate is also presented. [source]


Volatile Organic Compound Sensing by Quartz Crystal Microbalances Coated with Nanostructured Macromolecular Metal Complexes

CHEMISTRY - AN ASIAN JOURNAL, Issue 4 2010
M. Kimura Prof.
Abstract We report the construction of a molecular recognition layer composed of polyelectrolyte brushes and metal complexes on the surface of a quartz crystal microbalance (QCM) and the sensing abilities for various volatile organic compounds (VOCs). Atom-transfer radical polymerization of 2-(dimethylamino)ethyl acrylate from an initiator-terminated self-assembled monolayer yielded polyelectrolyte brushes on the surface of a weight-detectable quartz crystal microbalance. One end of a poly[(2-dimethylamino)ethyl methacrylate] brush was covalently attached onto the surface of a sensor. We found that metallophthalocyanines with four bulky pentaphenylbenzene substituents could adsorb volatile organic compounds selectively into their cavities. Macromolecular metal complexes were prepared by immersing polymer-brush-modified QCMs into an aqueous solution of sterically protected cobalt phthalocyanine. Anionic cobalt phthalocyanine was trapped in the polymer brushes and acted as a molecular receptor for the sensing of VOC molecules. [source]


Study of free radical polymerisation with dye photoinitiators containing a naphthoylenebenzimidazolone skeleton

COLORATION TECHNOLOGY, Issue 2 2008
Rados, aw Podsiad
A series of neutral and cationic dyes based on a naphthoylenebenzimidazolone skeleton have been synthesised and evaluated as potential light-absorbing chromophores for free radical polymerisation. The kinetic study of photoinitiated polymerisation of ethyl acrylate performed with the use of N -phenylglycine, ethyl 4- N,N -dimethylaminobenzoate, phenylthioacetic acid and phenoxyacetic acid have proved that the tested dyes are good electron-accepting photoinitiators. The results show that, in the photoinduced electron transfer from donor to excited singlet state of the dye, the radical anion is possibly formed via an associated donor,dye complex. [source]


High temperature copolymerization of styrene/ethyl acrylate: Reactivity ratio estimation in bulk and solution

ADVANCES IN POLYMER TECHNOLOGY, Issue 3 2004
Nahla Sahloul
Abstract Styrene/ethyl acrylate (Sty/EA) free-radical copolymerizations have been conducted in bulk with and without initiator and in solution using p -xylene and m -xylene (30 wt% and 60 wt% solvent level) at 100°C and 130°C. The monomer reactivity ratio values and their temperature dependence have been determined from low conversion copolymer composition data using the computer software package RREVM, which is based on the error in variables model (EVM) method. Copolymer composition data at low conversion confirmed the Mayo,Lewis model at both temperatures. The reactivity ratio values of the Sty/EA system do not seem to change with dilution by nonpolar solvents at low concentration from the reactivity ratio values obtained in bulk with and without initiator. However, xylene isomers were found to have a slight effect on the reactivity ratio value of ethyl acrylate when high solvent concentration was utilized. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 186,195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20009 [source]