المؤلفون: V.F. Gromov, A.P. Sheinker, P.M. Khomikovskii, A.D. Abkin

المصدر: Polymer Science U.S.S.R.. 16:423-429

مصطلحات موضوعية: chemistry.chemical_classification, chemistry.chemical_compound, Ammonia, Aqueous solution, Polymerization, Chemistry, Acrylamide, Inorganic chemistry, Polyacrylamide, General Engineering, Chain transfer, Caustic (optics), Polymer

الوصف: A study was made of the polymerization of acrylamide (AA) in two-phase systems containing water and in concentrated aqueous solutions in presence of ammonia or caustic soda. It was found that polymers prepared by polymerization in these systems, when the latter contain not less than 0·5 wt.% caustic soda, or 1·3 wt.% ammonia, dissolve, completely in water. The rate of chain transfer through β,β′,β″-nitriletripropionamide molecules was determined. The probable causes of the formation of soluble polyacrylamide in concentrated aqueous systems in the presence of ammonia or caustic soda are analysed.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::268aedf23b77f8f7b6dc28665e0ca8ebTest
https://doi.org/10.1016/0032-3950Test(74)90570-x

المؤلفون: P.M. Khomikovskii, A.D. Abkin, V.F. Gromov, T.P Osmanov

المصدر: Polymer Science U.S.S.R.. 21:1948-1956

مصطلحات موضوعية: chemistry.chemical_classification, Solvent, chemistry.chemical_compound, chemistry, Polymerization, Lithium bromide, Acrylamide, Radical, Inorganic chemistry, Radical polymerization, General Engineering, Salt (chemistry), Tetrahydrofuran

الوصف: The radical polymerization of acrylamide (AA) has been investigated in the presence of various solvents over lithium bromide (LiBr). Addition of salt has been found not to affect the total rate of the polymerization in water. The use of dimethyl sulphoxide or tetrahydrofuran caused the curves of the process rate plotted against salt concentration to show a peak of amplitude and position depending on the solvent polarity. Addition of water to the dimethyl sulphoxide (DMSO) reduces the effect of the salt on the process rate. The change of the total rate in DMSO on adding LiBr has been found to be due to a change of kp, as the k0 remains the same when various amounts of salt are present. The results are explained by a complex formation between the salt and the polymer radicals and by the conformation characteristics of the macromolecules in solution when LiBr is present.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::867c8916f1a09974763eefe21b993042Test
https://doi.org/10.1016/0032-3950Test(79)90103-5

المؤلفون: N.I. Gal'perina, T.O. Osmanov, V.F. Gromov, A.D. Abkin, P.M. Khomikovskii

المصدر: European Polymer Journal. 16:529-535

مصطلحات موضوعية: Chain propagation, Polymers and Plastics, Chemistry, Organic Chemistry, Radical polymerization, General Physics and Astronomy, Solution polymerization, Chain transfer, Chain termination, Photochemistry, Living free-radical polymerization, Cobalt-mediated radical polymerization, Polymerization, Polymer chemistry, Materials Chemistry

الوصف: The radical polymerizations of acrylamide and methacrylamide and of acrylic, methacrylic and fluoroacrylic acids have been studied in various solvents. The nature of the solvent affects the overall rate due to changes in kp and Ep. It has been shown that the effect of solvent also depends on the nature of the monomer. A possible explanation of the observed behaviour is discussed.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::81e3b47446082c4e746ba5e8332e3f26Test
https://doi.org/10.1016/0014-3057Test(80)90137-8

المؤلفون: T.O. Osmanov, V.F. Gromov, A.D. Abkin, P.M. Khomikovskii

المصدر: European Polymer Journal. 16:803-808

مصطلحات موضوعية: Polymers and Plastics, Bulk polymerization, Chemistry, Organic Chemistry, Radical polymerization, Cationic polymerization, General Physics and Astronomy, Solution polymerization, Chain-growth polymerization, Polymerization, Polymer chemistry, Materials Chemistry, Lewis acids and bases, Ionic polymerization

الوصف: The radical polymerization of acrylamide in various solvents in the presence of Lewis acids has been investigated. Considerable effects of LiBr, LiCl and CaCl 2 on the total reaction rate and the values of k p and k 1 for polymerization in DMSO or THF have been shown. For the polymerization of acrylamide in aqueous solution, addition of the salts does not affect the kinetic behaviour of the process. The observed effect of salts arises from complexation between the salt and the monomer and/or the propagating radicals.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::e80bcb28f15960bc32d0ae55bb0bd786Test
https://doi.org/10.1016/0014-3057Test(80)90108-1

المؤلفون: Gromov Vladimir F, P.M. Khomikovskii

المصدر: Russian Chemical Reviews. 48:1040-1054

مصطلحات موضوعية: Reaction rate, Solvent, chemistry.chemical_compound, Chain propagation, Monomer, chemistry, Polymerization, Aqueous medium, Polymer chemistry, Polar, General Chemistry

الوصف: The influence of the solvent on the rate of radical polymerisation and copolymerisation, observed and investigated in the last ten years and caused mainly by a change in the rate of the elementary chain propagation reaction, is discussed. The published data on the polymerisation and copolymerisation of a number of monomers in solvents of different types are surveyed. Attention is drawn to the fact that the greatest effects are observed for polar monomers, particularly for water-soluble monomers in an aqueous medium. The causes of the change in the overall rate of reaction, the constants kp, and the copolymerisation constants for different monomers are examined. The bibliography includes 104 references.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::9ac3ca1794270a634f2ee6b727e426d7Test
https://doi.org/10.1070/rc1979v048n11abeh002428Test

المؤلفون: V.F. Gromov, T.O. Osmanov, P.M. Khomikovskii, A.D. Abkin

المصدر: Polymer Science U.S.S.R.. 22:739-748

مصطلحات موضوعية: chemistry.chemical_classification, Chemistry, Inorganic chemistry, Radical polymerization, General Engineering, Salt (chemistry), chemistry.chemical_element, Solution polymerization, chemistry.chemical_compound, Reaction rate constant, Polymerization, Acrylamide, Polymer chemistry, Lithium chloride, Lithium

الوصف: A study was made of radical polymerization of acrylamide in dimethylsulphoxide in the presence of various inorganic salts. It was established that the addition of lithium chloride, or calcium chloride markedly changes reaction parameters, but zinc chloride has no influence on polymerization of acrylamide. An increase in the overall rate of the reaction in the presence of small amounts of salts is due to a higher propagation rate constant. With high salt concentrations as a consequence of a sudden increase in the viscosity of the reaction system the rate constant for termination also has a marked effect on the overall rate of polymerization. Complex formation between acrylamide and lithium and calcium chloride was established by NMR. Stability constants of these complexes were determined. Results are explained bearing in mind complex formation between the salt and reacting particles. It is possible that the rate of polymerization is also influenced by conformational variation of macromolecules in the presence of salts.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::af625d1cc34f22c66e97e753d779ec5bTest
https://doi.org/10.1016/0032-3950Test(80)90402-5

المؤلفون: N.I. Gal'perina, A.D. Abkin, V.F. Gromov, P.M. Khomikovskii, T.A. Gugunava

المصدر: Polymer Science U.S.S.R.. 17:1670-1677

مصطلحات موضوعية: Kinetic chain length, Living free-radical polymerization, Polymerization, Chemistry, Radical polymerization, Polymer chemistry, General Engineering, Cationic polymerization, Chain transfer, Solution polymerization, Ionic polymerization, Photochemistry

الوصف: The homogeneous radical polymerization of acrylic and α-fluoracrylic acids has been studied in solution in water, formamide and dimethylsulphoxide. For accrylic acid, a marked reduction in the rate of chain propagation and an increase in the activation energy for this reaction are observed on going along the series water, formamide, dimethyl sulphoxide. The effect of the nature of the solvent is expressed to a considerably lesser extent for the polymerization of α-fluoracrylic acid. The rate constant for chain propagation for acrylic acid in water is much higher than that for α-fluoracrylic acid (the values of kp at 20°C are 27, 200 for acrylic acid and 2600 for α-fluoracrylic acid). Possible reasons for the observed phenomena, principally connected with interaction between the radicals participating in polymerization and the solvent, are discussed.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::6e4dff53cdecf7974aa2c0f0cbba8bffTest
https://doi.org/10.1016/0032-3950Test(75)90169-0

المؤلفون: N.I. Gal'perina, A.D. Abkin, V.F. Gromov, P.M. Khomikovskii

المصدر: Polymer Science U.S.S.R.. 18:637-641

مصطلحات موضوعية: Solvent, chemistry.chemical_compound, Monomer, chemistry, Homogeneous, Radical, Polymer chemistry, General Engineering, Copolymer, Molecule, Reactivity (chemistry), Acrylic acid

الوصف: The homogeneous radical copolymerization of acrylic with fluoro-acrylic acid was studied at 50°C in water and DMSO as solvents. The compositions found in water were used to calculate the reactivity ratios, i.e. r 1 = 0·37 ± 0·06, r 2 = 1·58 ± 0·10; they were also determined from the kinetic data, i.e. r 1 = 0·50 ± 0·05, r 2 = 0·70 ± 0·05 (copolymerization in DMSO); r 1 = 0·50 ± 0·15, r 2 = 1·50 ± 0·10 (in water). A large difference was found between the reactivities of the co-monomers with the polymeric radicals in water. The acrylic acid radical was found to be more reactive, but the more reactive monomer was fluoro-acrylic acid. The reactivities of radicals and monomers were similar when the copolymerization was carried out in DMSO and this seems to be due to complex formation by the polymeric radicals with the solvent molecules.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::777d277faa6cca4247fe8721632f6386Test
https://doi.org/10.1016/0032-3950Test(76)90260-4

المؤلفون: L.P. Mezhirova, A.D. Abkin, A.V. Matveeva, M.K. Iakovleva, P.M. Khomikovskii, S.S. Medvedev

المصدر: Polymer Science U.S.S.R.. 1:34-40

مصطلحات موضوعية: γ radiation, Chemical engineering, Chemistry, General Engineering, Precipitation polymerization, Emulsion polymerization, Suspension polymerization, Solution polymerization

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::15ab4c1b6ceb83296570c803764eef4cTest
https://doi.org/10.1016/0032-3950Test(60)90231-8

المؤلفون: A.V. Matveyeva, A.D. Abkin, V.F. Gromov, P.M. Khomikovskii

المصدر: Polymer Science U.S.S.R.. 9:1616-1623

مصطلحات موضوعية: chemistry.chemical_classification, chemistry.chemical_compound, Work (thermodynamics), Monomer, Aqueous solution, chemistry, Chemical engineering, Polymerization, Intrinsic viscosity, Acrylamide, General Engineering, Polymer, Methanol

الوصف: T~E polymerization of acrylamide has previously been studied mainly in solution in water [1-12], in which the monomer and polymer are readily soluble, and also in the solid state under the influence of high energy radiation [13]. Some isolated experiments on polymerization of acrylamide in methanol, which precipitates the polymer, in water and in water-alcohol mixtures [14] have shown that increase in the water content of the water-alcohol mixture leads to increase in the specific viscosity of the polymer. The rate of polymerization in dilute aqueous solution is approximately an order of magnitude higher than in methanol. The present work is devoted to a more detailed examination of the effect of methanol on the polymerization of acrylamide.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::33c7f176950380aa6476e7d13296935aTest
https://doi.org/10.1016/0032-3950Test(67)90399-1