Showing papers on "Methyl acrylate published in 2014"
TL;DR: Minimal polymerization in the absence of light confers temporal control and alludes to potential application at one of the frontiers of materials chemistry whereby precise spatiotemporal "on/off" control and resolution is desirable.
Abstract: Photoinduced living radical polymerization of acrylates, in the absence of conventional photoinitiators or dye sensitizers, has been realized in “daylight’”and is enhanced upon irradiation with UV radiation (λmax ≈ 360 nm). In the presence of low concentrations of copper(II) bromide and an aliphatic tertiary amine ligand (Me6-Tren; Tren = tris(2-aminoethyl)amine), near-quantitative monomer conversion (>95%) is obtained within 80 min, yielding poly(acrylates) with dispersities as low as 1.05 and excellent end group fidelity (>99%). The versatility of the technique is demonstrated by polymerization of methyl acrylate to a range of chain lengths (DPn = 25–800) and a number of (meth)acrylate monomers, including macromonomer poly(ethylene glycol) methyl ether acrylate (PEGA480), tert-butyl acrylate, and methyl methacrylate, as well as styrene. Moreover, hydroxyl- and vic-diol-functional initiators are compatible with the polymerization conditions, forming α,ω-heterofunctional poly(acrylates) with unparalleled ...
312 citations
TL;DR: In this article, a photoredox catalyst, Ru(bpy)3Cl2, was used to control the polymerization of methacrylates, acrylsates, and acrylamides in the presence of thiocarbonylthio compounds.
Abstract: This study reports a highly efficient photoredox catalyst, Ru(bpy)3Cl2, capable of controlling the polymerization of methacrylates, acrylates, and acrylamides in the presence of thiocarbonylthio compounds via a photoinduced electron transfer–reversible addition–fragmentation chain (PET-RAFT) process. This polymerization technique was performed in a closed vessel in the presence or absence of air. Online Fourier transform near-infrared spectroscopy (FTNIR) was employed to monitor the monomer conversions of methyl methacrylate, methyl acrylate, and N,N′-dimethylacrylamide in the presence or absence of air. Interestingly, after an induction period, the polymerization proceeded in the presence of air to yield well-defined polymers (PDI < 1.20). The polymers were characterized by 1H NMR, UV–vis spectroscopy, and gel permeation chromatography. Excellent end-group retention was also demonstrated by NMR, UV–vis, and successive chain extensions of the resulting homopolymers to yield diblock and multiblock copolyme...
251 citations
TL;DR: In this article, photo-induced copper-mediated radical polymerization of methyl acrylate (MA) is carried out in DMSO at 15 °C in a tubular photo-flow reactor as well as in a glass-chip based microreactor.
152 citations
Karlsruhe Institute of Technology1, Clausthal University of Technology2, University of Göttingen3, University of Western Sydney4, University of Lyon5, Australian National University6, Queen's University7, University of Hasselt8, Slovak Academy of Sciences9, University of Canterbury10, Eindhoven University of Technology11
TL;DR: In this article, a benchmark dataset for the propagation rate coefficient (kp) of methyl acrylate (MA) in the bulk is presented, which includes data from three laboratories and new data from a fourth laboratory.
114 citations
TL;DR: In this paper, photoinduced living radical polymerization of acrylates is achieved upon UV irradiation (λmax ≈ 360 nm) in the presence of an aliphatic tertiary amine ligand (Me6-Tren), yielding poly(acrylsates) with near perfect retention of end group fidelity, the effect of the nature of the solvent on the rate of polymerization was investigated in order to expand the scope and identify the limitations of the system.
Abstract: Photoinduced living radical polymerization of acrylates is achieved upon UV irradiation (λmax ≈ 360 nm) in the presence of an aliphatic tertiary amine ligand (Me6-Tren) in the presence of low concentrations of CuBr2, yielding poly(acrylates) with near perfect retention of end group fidelity. The effect of the nature of the solvent on the rate of polymerization was investigated in order to expand the scope and identify the limitations of the system. Subsequently, a range of acrylic monomers containing hydrophobic and hydrophilic substituents have been screened, including lauryl acrylate, octadecyl acrylate and diethylene glycol ethyl ether acrylate, all of which present low dispersities (Đ ≈ 1.1) at very high conversions. Functional monomers, including glycidyl acrylate and solketal acrylate, were also found to be tolerant to the photomediated reaction. Finally, solketal acrylate was copolymerized with methyl acrylate which, following deprotection of the pendant ketal group, furnished an amphiphilic dibloc...
98 citations
TL;DR: An expedient one-step synthesis of 2-iodoglycals and 2-bromoglycal from glycals using NIS/AgNO3 and NBS/ AgNO3 as reagent systems has been developed and the utility of these 2-haloglycals has been demonstrated by converting them into 2C-branched glycals via the Heck coupling reaction.
76 citations
TL;DR: A series of benzo-linked phosphine-diethyl phosphonate (P-PO) and (P-(PO)2)PdMe(2,6-lutidine)+ complexes were synthesized in this article.
73 citations
TL;DR: Vanadium phosphorus oxides (VPOs) fabricated by employing poly ethylene glycol (PEG) additive were used as catalysts for efficient conversion of acetic acid (methyl acetate) and formaldehyde to acrylic acid(methyl acrylate) as mentioned in this paper.
68 citations
TL;DR: The surface of amine-fuctionalized magnetic nanoparticles was coated with polyamidoamine dendrimer via of alkylation of Amine groups with methyl acrylate (Micheal addition route) as mentioned in this paper.
65 citations
TL;DR: Copolymers of methyl acrylate and [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AETAC) with 55% charge density exhibited comparable performance in clay settling test, real water jar test, and sludge dewatering, when compared to AM-based commercial product in the real wastewater treatment application.
63 citations
TL;DR: Olefin cross-metathesis of unsaturated fatty acid methyl ester (FAME) derived benzyl carbamates with methyl acrylate is described in this article, where the obtained byproduct, an α,β-unsaturated ester, was further modified via thia-Michael addition reactions in order to synthesize branched AA-type or AB-type monomers for the preparation of polyesters.
TL;DR: In this article, the synthesis and characterisation of new hydrogen-bond-rich ionic liquids and studies of their catalytic performance in Diels-Alder reactions are described, where D-Glucose and chloroalcohols were used as the raw materials and as the sources of hydroxyl groups for the synthesis of ionic-liquid cations, whereas weakly coordinating bis(trifluoromethylsulfonyl)imide was used as anion.
TL;DR: Probably, two active species are generated in the binuclear palladium catalyst system and are responsible for the bimodal feature of the GPC curves in ethylene polymerization.
Abstract: A series of binuclear nickel/palladium catalysts C4–C7 with conjugated α-diimine ligands were designed, prepared and fully characterized. The binuclear nickel complexes C6 and C7 were activated by modified methylalumoxanes (MMAO) to generate highly active ethylene polymerization catalysts with activities up to 1050 kg [mol (Ni) h]−1. The activity of C7 is twice that of the mononuclear analogue under the same conditions. The effects of the catalyst structure, cocatalyst ratio, polymerization time, solvent and feeding monomer on the catalytic activities, molecular weight and branching structures of the resulting polymers were evaluated. The binuclear palladium complexes C4–C5 produced polyethylene with two separate peaks in GPC curves in ethylene polymerization. In contrast, the mononuclear analogue C3 produces polyethylene with a unimodal GPC curve. Probably, two active species are generated in the binuclear palladium catalyst system and are responsible for the bimodal feature of the GPC curves. The performance of the binuclear palladium complexes in ethylene/methyl acrylate copolymerization was also investigated.
TL;DR: In this article, a hybrid dry-jet gel solution spinning technique for the very high molecular weight (VHMW) polyacrylonitrile-co-methyl acrylate polymers with weight average molecular weights of at least 1.7 million g/mole were repeatedly achieved on a laboratory scale using emulsion polymerization.
TL;DR: In this paper, a facile and effective approach was developed to fabricate dual temperature and pH-sensitive hollow nanospheres utilizing an atom transfer radical polymerization (ATRP) method.
Abstract: A facile and effective approach was developed to fabricate dual temperature- and pH-sensitive hollow nanospheres utilizing an atom transfer radical polymerization (ATRP) method. To do this silica nanoparticles were used as primary cores that could be etched by an hydrofluoric (HF) aqueous solution. Due to uncontrolled ATRP of acrylic acid (AA) methyl acrylate (MA) was polymerized via surface-initiated ATRP (SI-ATRP) a and poly(2-hydroxyethyl methacrylate) (PHEMA) block was added via the same approach. To synthesize poly(AA-co-HEMA)-grafted silica nanoparticles polymethyl acrylate (PMA) chains were hydrolyzed to polyacrylic acid (PAA) using an aqueous NaOH solution. PAA segments were partially crosslinked via an esterification reaction of –COOH groups with 1,4-butanediol. Finally, poly(AA-co-HEMA) hollow nanospheres were fabricated by etching silica cores with an HF aqueous solution. The structure of the nanospheres was revealed by transmission electron microscopy (TEM). These hollow nanospheres consisting of poly(AA-co-HEMA) in their structure showed dual pH- and thermo-sensitive properties as measured by dynamic light scattering (DLS). The hydrodynamic diameter was measured as an affected parameter under different pH (3–12) and temperature (25–55 °C) conditions. Results showed that by decreasing pH or by increasing temperature the hydrodynamic diameter decreased and a lower critical solution temperature (LCST) point was observed.
TL;DR: A series of biodegradable acrylic terminated polyurethanes based on poly(ε-caprolactone) diol, aliphatic 1,6-hexamethylene diisocyanate and hydroxyethyl methyl acrylate was synthesized as potential materials for hard tissue biomedical applications and indicated that the mechanical properties of PUAs were governed considerably by crystalline microstructure, and hard segment content.
TL;DR: In this article, photo-cross-linkable polymers were synthesized by click-chemistry and characterized by using various spectroscopic techniques and the rate of cross-linking was evaluated by absorption spectroscopy.
TL;DR: Olefin cross-metathesis has been demonstrated to be a modular pathway for synthesis of a series of functionalized cellulose esters as discussed by the authors, which can be used for hydrogenation of these α,β-unsaturated esters and acids, thereby eliminating the potential for radical-induced crosslinking during storage.
TL;DR: The rate constants of activation and termination were determined for SET-LRP/SARA-ATRP polymerizations of methyl acrylate and addition of the CuBr2 deactivator at the beginning of the reaction is found to result in a higher proportion of dead chains due to rapid termination of short chains.
Abstract: The rate constants of activation and termination were determined for SET-LRP/SARA-ATRP polymerizations of methyl acrylate. Measurement of the rate of generation of CuBr2 throughout the reaction (using data from Levere et al., Macromolecules 2012, 45, 8267–8274) allowed evaluation of the chain length dependence of the two rate constants, which were found to be 1.25(9) × 10–4DPn–0.51(3) cm·s–1 (activation) and 3.1(1) × 109DPn–0.49(2) L·mol–1·s–1 (termination). Addition of the CuBr2 deactivator at the beginning of the reaction is found to result in a higher proportion of dead chains due to rapid termination of short chains.
TL;DR: The applied 1,3-benzoxazine-thiol process based on catalytic opening of the lateral benzoxazine rings by thiols is proposed as a new thiol-X chemistry that offers a facile and efficient route to exploring the many possibilities in macromolecular synthesis.
TL;DR: In this article, a hybrid approach has been designed by coupling the double hybrid XYG3 and the hybrid B3LYP exchange correlation functionals, using the extended ONIOM scheme, to explore the role of the MeI electrophile for the formation of methyl acrylate from the initial nickelalactone complex.
TL;DR: In this article, the development of microreactor protocols for the successful continuous flow end group modification of atom transfer radical polymerization precursor polymers into azide end-capped materials and the subsequent copper-catalyzed azide alkyne click reactions with alkynes, in flow is presented.
Abstract: This study presents the development of microreactor protocols for the successful continuous flow end group modification of atom transfer radical polymerization precursor polymers into azide end-capped materials and the subsequent copper-catalyzed azide alkyne click reactions with alkyne polymers, in flow By using a microreactor, the reaction speed of the azidation of poly(butyl acrylate), poly(methyl acrylate), and polystyrene can be accelerated from hours to seconds and full end group conversion is obtained Subsequently, copper-catalyzed click reactions are executed in a flow reactor at 80 °C Good coupling efficiencies are observed and various block copolymer combinations are prepared Furthermore, the flow reaction can be carried out in only 40 min, while a batch procedure takes several hours to reach completion The results indicate that the use of a continuous flow reactor for end group modifications as well as click reactions has clear benefits towards the development and improvement of well-defined polymer materials © 2014 Wiley Periodicals, Inc J Polym Sci, Part A: Polym Chem 2014, 52, 1263–1274
TL;DR: In this paper, a series of novel N-pyridylpyrazolecarboxamides containing an amino acid methyl ester and their analogues were designed and synthesized.
Abstract: On the basis of the commercial insecticide chlorantraniliprole, a series of novel N-pyridylpyrazolecarboxamides containing an amino acid methyl ester and their analogues were designed and synthesized. Their chemical structures were established on the basis of corresponding 1 H NMR spectroscopy, 13C NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. The insecticidal activities of the new compounds against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) were evaluated. The results of bioassays indicated that most of the compounds showed moderate to high activities at the tested concentration, of which the compounds 6 containing a methyl acrylate substructure had excellent larvicidal activity; for example, 6a displayed 100% larvicidal activity against P. xylostella at the concentration of 0.005 mg/L, whereas the activities of both compounds 6g and 6h against M. separata were 100% at 2.5 mg/L. The calcium imaging technique experiment results s...
TL;DR: In this article, an enantioselective cross-dimerization between conjugated dienes and substituted alkenes was shown to be possible using naphthalene.
TL;DR: In this article, the Single Electron Transfer-Living Radical Polymerization (SET-LRP) was used to control the radical polymerization of o-nitrobenzyl acrylate (NBA).
Abstract: Polymers containing o-nitrobenzyl esters are promising for preparation of light sensitive materials. o-Nitrobenzyl methacrylate has already been polymerized by controlled ATRP or RAFT. Unfortunately, the radical polymerization of o-nitrobenzyl acrylate (NBA) was not controlled until now due to inhibition and retardation effects coming from the nitro-aromatic groups. Recent developments in the Single Electron Transfer–Living Radical Polymerization (SET–LRP) provide us an access to control this NBA polymerization and living character of this NBA SET–LRP is demonstrated. Effects of CuBr2 and ligand concentrations, as well as Cu(0) wire length on SET–LRP kinetics are shown presently. A first-order kinetics with respect to the NBA concentration is observed after one induction period. SET–LRP proceeds with a linear evolution of molecular weight and a narrow distribution. High initiation efficiency close to 1 and high chain-end functionality (∼93%) are reached. Chain extension of poly(o-nitrobenzyl acrylate) is realized with methyl acrylate (MA) to obtain well defined poly(o-nitrobenzyl acrylate)-b-poly(methyl acrylate) (PNBA-b-PMA). Finally, light-sensitive properties of PNBA are checked upon UV irradiation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2192–2201
TL;DR: In this article, a novel heterogeneous base catalyst was synthesized based on the distillation-precipitation-polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups using N,N-dimethylaminoethyl acrylamide (MNP@PDMA) catalyst.
Abstract: A novel heterogeneous catalyst has been synthesized based on the distillation–precipitation–polymerization of methyl acrylate onto modified magnetic nanoparticles followed by the amidation of the methyl ester groups using N,N-dimethylethylenediamine. The resulting poly(dimethylaminoethyl acrylamide) coated magnetic nanoparticles (MNP@PDMA) catalyst was characterized using an array of sophisticated analytical techniques, including FT-IR, TGA, SEM, TEM, CHN, vibrating sample magnetometer (VSM), and XRD analysis. The resulting heterogeneous base catalyst allowed the performance of a domino Knoevenagel condensation/Michael addition/cycloaddition reaction toward the synthesis of 4H-benzo[b]pyranes in excellent yields using water as the reaction medium. The multilayered and polymeric identity of the coated material on the surface of the magnetic nanoparticles provides many catalytic units resulting in the high loading level and high stability of the catalyst. Straightforward magnetic separation and recycling of the catalyst for up to 5 runs is possible without any significant loss of efficiency.
TL;DR: In this article, the synthesis and properties of novel (A-g-D)(B-alt-C)mD-type heterografted toothbrush-like copolymers are described.
TL;DR: The kinetic data obtained for a broad range of target molecular weights revealed very fast polymerization rates, low dispersity values (Đ < 1.05) and well-defined chain-end functionalities.
Abstract: An unusual synergistic effect between 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6) and dimethyl sulfoxide (DMSO) mixtures is reported for the supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of methyl acrylate (MA) using a catalytic system composed by sodium dithionate (Na2S2O4) and CuBr2/Me6TREN (Me6TREN: tris[2-(dimethylamino)ethyl]amine) at room temperature. To the best of our knowledge, the use of ionic liquids (IL) has never been reported for the SARA ATRP. The kinetic data obtained for a broad range of target molecular weights revealed very fast polymerization rates, low dispersity values (Đ < 1.05) and well-defined chain-end functionalities.
TL;DR: A family of silver(I) complexes obtained by reactions of 4,4'-di(2-oxazolinyl)biphenyl (L) and AgOOCCF3 in different reaction media affords the highest yield, in which the particular size of the channels in 3 led to its selective catalytic performance.
Abstract: A family of silver(I) complexes, [Ag2(L)2(OOCCF3)2] (1), [Ag(L)0.5(OOCCF3)] (2), [Ag(L)2](OOCCF3)(H2O)2 (3), was obtained by reactions of 4,4′-di(2-oxazolinyl)biphenyl (L) and AgOOCCF3 in different reaction media. Compound 1 has a 1D chain structure with alternative connections between the Ag(I) and L ligand. When the crystal nucleation inductor, pyrazine, was added into the reaction system, complex 2 was isolated with no pyrazine observed in its structure. In 2, the 1D inorganic chains formed by Ag(I) cations and OOCCF3− anions were connected by the L ligand to produce a 2D network. When a different inductor, imidazole, was added into the reaction system, 3 with (4,4) topology was synthesized, and again no imidazole was found in 3. When 1–3 were used as catalysts for cycloaddition reactions between imino esters and methyl acrylate, 3 affords the highest yield, in which the particular size of the channels in 3 led to its selective catalytic performance.
TL;DR: In this paper, the authors used a divergent method and a "grafting from" technique by alternate amidization of terminal ester groups with ethylenediamine and Michael addition of methyl acrylate to the yielding amino groups.
Abstract: Carbon nanotubes (CNTs) are often used after modification. Poly(amidoamine) (PAMAM) dendrimers modified CNTs have attracted attentions due to their rich terminal amino groups. However, direct grafting of PAMAM dendrimers on CNTs’ surface is limited by the steric hindrance and its supply. De novo growth of PAMAM on multi-walled carbon nanotubes (MWCNTs), i.e., PAMAM@CNTs, is expected to eliminate the limits since the adopted reagents are readily available small molecular chemicals. It was realized using a divergent method and a “grafting from” technique by alternate amidization of terminal ester groups with ethylenediamine and Michael addition of methyl acrylate to the yielding amino groups. Spectral analysis, including Fourier transform infrared, Raman, hydrogen nuclear magnetic resonance, and X-ray photo-electron spectroscopy, verified that the functional groups were covalently grafted on the surface of MWCNTs, while thermogravimetric and elemental analysis showed that these groups were exponentially grown on MWCNTs, suggesting the formation of a dendritic PAMAM. Besides, high resolution transmission electron microscopy also confirmed that the spherical PAMAM was formed on the CNTs’ surface and an average particle size of 15–20 nm for G8.0-dendrimers was obtained.