Low temperature initiation by methylene bis(diethyl malonate)–Ce(IV) redox system in organic solvents
TL;DR: In this article, an initiator for triethyl phosphate for polymerization of methyl methacrylate at room temperature is described. But the initiator is not shown to have a high polymerization yield at moderate concentration ratios.
About: This article is published in European Polymer Journal.The article was published on 2001-12-01. It has received 9 citations till now. The article focuses on the topics: Diethyl malonate & Methylene.
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TL;DR: In this paper, a combination of isocyanate-acrylate and hydroxylated acrylate monomers has been cured by heating and UV-irradiation in the presence of a cerium IV salt thermal initiator and an acylphosphine oxide photoinitiator.
35 citations
TL;DR: The BPO/amine redox system was shown to greatly accelerate the hardening of the acrylic resins in the shadow areas, a hard coating being obtained after a few minutes at room temperature as mentioned in this paper.
32 citations
TL;DR: In this paper, the dependence of polymerization yield and the molecular weight of polymer on the initiator concentration (nMSA =n Ce(IV)) at different acid concentrations, polymerization time, temperature, and concentration of sulfuric acid was investigated.
Abstract: By using mercaptosuccinic acid-cerium(IV) sulfate and mercaptosuccinic acid-KMnO4 redox systems in acid aqueous medium, the polymerization of acrylamide monomer was performed at room temperatures. Water soluble acry- lamide polymers which contain mercaptosuccinic acid end-groups were synthesized. The dependence of polymerization yield and the molecular weight of polymer on the initiator concentration(nMSA =n Ce(IV)) at different acid concentrations, polymerization time, temperature, and concentration of sulfuric acid was investigated. The decrease in the initiator concen- tration resulted in an increase in the molecular weight but a decrease in the yield. The increase of reaction temperature from 20 to 60°C resulted in an increase in the molecular weights and slight decrease of the yield of polymer. Cerium and man- ganese ions are reduced to Ce(III) and Mn(II) ions respectively in polymerization reaction. The existence of Ce(III) ion bound to polymer was investigated by UV-visible spectrometry and fluorescence measurements. The amount of Mn(II) which is incorporated to the polymer was determined.
16 citations
TL;DR: In this article, a facile method was developed to prepare polyacrylonitrile/montmorillonite (PAN/MMT) nanocomposites using the surface-initiated redox polymerization of AN in the aqueous phase.
Abstract: We have developed a facile method to prepare polyacrylonitrile/montmorillonite (PAN/MMT) nanocomposites using the surface-initiated redox polymerization of acrylonitrile (AN) in the aqueous phase. The MMT silicate surfaces were first treated with diethanolamine, and the modified MMT (DEA-MMT) was subsequently used together with the Ce(IV) salt to serve as a redox system. The PAN chains growing on a surface-tethered DEA expand the interlayer space, and thus lead to intercalated/exfoliated nanocomposites. The nano-morphology of the prepared nanocomposites depends on the AN/OH molar ratio in feed. An exfoliated PAN/MMT nanocomposite was obtained when the feeding AN/OH molar ratio = 300 was used. The molecular weight of PAN in the nanocomposites prepared by the present method is also dependent on the AN/OH molar ratio in feed and can be up to ca. 160,000 g/mol. The differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) analyses show that the increasing fraction of exfoliated silicate structures should enhance the contact interface between the silicate and polymer, resulting in the higher glass transition temperature and thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
11 citations
TL;DR: Amphiphilic copolymer of acrylamide (AAm) and butadiene was synthesized by radical initiation using the hydroxy terminated polybutadiene (HTPB) and ceric ammonium nitrate (CAN) macroredox initiator in heterogenous medium in the presence of nitric acid at 35°C in air as discussed by the authors.
Abstract: Amphiphilic copolymer of acrylamide (AAm) and butadiene was synthesized by radical initiation using the hydroxy terminated polybutadiene (HTPB) and ceric ammonium nitrate (CAN) macroredox initiator in heterogenous medium in the presence of nitric acid at 35°C in air. The resulting product was characterized by IR, NMR, viscosity and swelling measurements. Imidization of some AAm units was inferred from NMR spectroscopy and swelling measurement. The product adsorbed Ni(II) and Fe(II) ions from aqueous solution and selectively released Ni(II) only. The release pattern for hydrophilic dye was similar to the usual fractional release behavior of drug release observed for hydrogel systems.
9 citations
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01 Jan 2003
TL;DR: In this paper, the authors present a method for the synthesis of organic compounds using Spectroscopic methods and Spectral Spectral Methods (SSTM) with a focus on alicyclic and aliphatic compounds.
Abstract: 1. Organic synthesis 2. Experimental techniques. 3. Spectroscopic methods. 4. Solvents and reagents. 5. Aliphatic compounds. 6. Aromatic compounds. 7. Selected alicyclic compounds. 8. Selected heterocyclic compounds. 9. Investigation and characterisation of organic compounds. 10. Physical constants of organic compounds.
6,578 citations
61 citations
TL;DR: In this paper, the polymerization of acrylamide initiated by the acidic permanganate-ascorbic acid redox pair has been studied in aqueous media at 30 ± 0.2°C in nitrogen atmosphere.
Abstract: The polymerization of acrylamide initiated by the acidic permanganate–ascorbic acid redox pair has been studied in aqueous media at 30 ± 0.2°C in nitrogen atmosphere. The initial rate of polymerization has been found to be proportional to nearly the first power of the catalyst KMnO4 concentration within the range 6.0 × 10−3–14.0 × 10−3 mole/l. The rate is proportional to the first power of the monomer concentration within the range 4.00 × 10−2–12.0 × 10−2 mole/l. However, the rate of polymerization is independent of ascorbic acid concentration within the range 3.0 × 10−3–6.0 × 10−3 mole/l., but the further increase of the concentration depresses the rate of polymerization as well as maximum conversion. The initial rate increases but the maximum conversion decreases as the temperature is increased within the range 20–35°C. The overall energy of activation has been found to be 9.8 kcal/mole. The optimum amount of sulfuric acid is essential to initiate the polymerization but its presence in excess produces no effect either on the rate of reaction or the maximum conversion. Water-miscible organic solvents and salts, e.g., CH3OH, C2H5OH, (CH3)2CHOH, KCl, and Na2SO4, depress the rate. Slight amounts of MnSO4 · H2O and a complexing agent NaF increase the rate of polymerization. Cationic and anionic detergents have been found to decrease and increase the rate, respectively, while nonionic surfactants have no effect on the rate of polymerization.
31 citations
TL;DR: In this paper, the dependence of polymerization yields and molecular weights of polymers on the mole ratio of acrylamide monomer to glycine, the polymerization time, the temperature, and the concentration of sulfuric acid were investigated.
Abstract: Glycine-Ce(IV) salts and -KMnO 4 initiator systems were used for the polymerization of acrylamide, resulting in water-soluble polyacrylamide, which contains amino acid end groups. The dependence of polymerization yields and molecular weights of polymers on the mole ratio of acrylamide monomer to glycine, the polymerization time, the temperature, and the concentration of sulfuric acid were investigated. The decrease in the mole ratio of acrylamide to glycine resulted in a decrease in the molecular weight, and an increase in the yield of acrylamide polymer, which contains a glycine end group. With increasing acid concentration of the polymeric solution, the polymerization yield and the molecular weight of polymer decrease. Ce(IV) and Mn(IV) reduced to Ce(III) and Mn(II) in the polymerization reaction. The amounts of Ce(III) and Mn(II) bound to polymer were determined. The composition of the polymerization product was investigated and a bimodal character of the molecular weight distribution was observed. The mechanism of this phenomena is discussed.
30 citations