Copolymerization of acrylamide and sodium 2-acrylamido-2-methylpropanesulfonate in water-ethanol mixtures

Homogeneous copolymerization of acrylamide and sodium 2-acrylamido-2-methylpropanesulfonate was carried out in water-ethanol mixtures at pH 9 in the presence of potassium peroxosulfate as promoter in the temperature range 40–70°C. The copolymerization kinetics and molecular characteristics of the copolymers formed were studied in relation to the composition of water-ethanol mixtures, reagent concentrations, temperature, and degree of monomer conversion.     

Copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in water-dimethyl sulfoxide solutions

The solvent effect on the kinetic features of the synthesis and molecular characteristics of the copolymers in homogeneous radical copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in water and water-dimethyl sulfoxide mixtures (75: 25, 50: 50, 25: 75) at pH 9 and 60°C in the presence of potassium persulfate was studied     

Concentration effect in copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in aqueous solutions

The effect of the concentration of the initial monomer mixture, the comonomer ratio, and temperature on the kinetic parameters of the process and the characteristics of the resulting copolymers in the homogeneous copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate in aqueous solutions at 50–80°C in the presence of potassium persulfate is studied. The initial rate of copolymerization and the molecular mass of copolymers increase with the total initial concentration of the monomer mixture and the content of sodium 2-acrylamido-2-methylpropanesulfonate. As temperature increases, the initial rate of copolymerization increases and the molecular mass of the copolymer diminishes. When copolymerization is performed in 10, 30, and 40% aqueous solutions of the monomers, the resulting copolymers are enriched in sodium acrylate units. The content of sodium 2-acrylamido-2-methylpropane-sulfonate units in the copolymer slightly increases with an increase in the total initial concentration of the monomer mixture.     

Copolymerization of sodium 2-crylamido-2-methylpropanesulfonate with sodium acrylate in concentrated aqueous solutions

The kinetic features of potassium persulfate-initiated homogeneous radical copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate (M₁) with sodium acrylate (M₂) in concentrated aqueous solutions and NaCl aqueous solutions at pH 9 and T = 60°C have been studied. The initial rate of copolymerization increases with the concentration of each monomer, the total concentration of comonomers (M₁ + M₂), the concentration of initiator, and the concentration of NaCl and shows an extreme change with an increase in the content of M₂ in the initial monomer mixture. The molecular mass of the copolymer shows an extreme dependence on the content of M₂ in the initial monomer mixture; it drops with an increase in the concentration of NaCl and remains unchanged with conversion. For copolymerization in water and 2 M NaCl, r ₂ > r ₁. The number of M₂ units in the copolymer does not change with conversion and increases on addition of NaCl owing to a gain in r ₂.     

Sedimentation of kaolin suspension with copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate

The sedimentation kinetics of kaolin suspension under the action of copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with sodium acrylate was studied. The infl uence exerted on the process by the concentration, molecular weight, chemical composition, and conformational state of copolymer macromolecules in solution, and also by the concentration and particle size of the dispersed phase and by salt additives (NaCl, CaCl₂) was examined.     

Copolymerization of acrylamide with sodium acrylate in aqueous salt solutions

Kinetic relationships in homogeneous radical copolymerization of acrylamide with sodium acrylate, initiated by potassium peroxosulfate in concentrated aqueous solutions at 60°C, were examined in relation to the ionic strength of the solution and pH of the medium.     

Stabilization of kaolin suspension in the presence of copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with N-vinylpyrrolidone

The kinetics of sedimentation of kaolin suspension in the presence of copolymers of sodium 2-acrylamido-2-methylpropanesulfonate with N-vinylpyrrolidone was studied as influenced by the concentrations, molecular weight, and chemical composition of the copolymer and by the concentration of salts added (NaCl, CaCl₂).     

Viscometric study of poly(sodium 2-acrylamido-2-methylpropanesulfonate) and two random copolymers

Effects of the polyanion synthesis conditions and composition on the viscometric behavior of poly(sodium 2-acrylamido-2-methylpropanesulfonate) (PAMPS) and two random copolymers, poly(sodium 2-acrylamido-2-methylpropanesulfonate-co-methylmethacrylate) (PAMPSMM) and poly(sodium 2-acrylamido-2-methylpropanesulfonate-co-tert-butylacrylamide) (PAMPSTBA), in a wide range of concentrations were reported in this paper. The experimental data obtained in salt-free aqueous solution were plotted in terms of the Fuoss and the Rao equations in order to obtain the intrinsic viscosity values. The C∗ values obtained as the reciprocal of the intrinsic viscosity were compared with the experimentally determined values and with those calculated according to the Odijk theory. An acceptable agreement between C∗ values obtained by different approaches was found for the PAMPS samples with high molar masses (0.83 × 10⁶-1.4 × 10⁶ g/mol). For the same charge density and the same concentration the reduced viscosity values were higher for PAMPSMM comparative with PAMPSTBA indicating a higher chain extension of the former copolymer.     

Spontaneous copolymerization of 2-acrylamido-2-methylpropanesulfonic acid with acrylamide and acrylonitrile in concentrated aqueous solutions

Spontaneous copolymerization of 2-acrylamido-2-methylpropanesulfonic acid with acrylamide and acrylonitrile in concentrated acidic aqueous solutions was studied.     

Radical copolymerization of sodium 2-acrylamido-2-methylpropane sulfonate and sodium acrylate in water-alcohol solutions

The effect of the nature of a solvent on the kinetic parameters of the process and the intrinsic viscosities of copolymers formed by the homogeneous free-radical copolymerization of the sodium salt of 2-acrylamido-2-methylpropane sulfonic acid and the sodium salt of acrylic acid initiated by potassium persulfate in water, water-methanol mixtures (92: 8, 84: 16, 75: 25, 50: 50), and water-isopropanol (50: 50) mixtures at pH 9 and 60°C is studied. The initial rate of copolymerization increases with increases in the concentrations of the comonomers and initiator, the content of 2-acrylamido-2-methylpropane sulfonic acid in the initial monomer mixture, and the content of water in a water-methanol mixture and in the sequence of solvents water-methanol < water-isopropanol. The intrinsic viscosity and yield of the copolymer grow when the content of 2-acrylamido-2-methylpropane sulfonic acid in the initial monomer mixture and water in water-methanol mixtures are increased and when isopropanol is replaced with methanol. The reactivity ratios of the monomers in water-methanol (50: 50) and water-isopropanol (50: 50) mixtures are determined.     

Copolymerization of acrylamide with ammonium acrylate in concentrated aqueous solutions

The kinetics of formation of water-soluble copolymers of acrylamide and ammonium acrylate with various molecular properties by copolymerization in concentrated aqueous solutions at 60°C in the presence of potassium persulfate initiator was studied by dilatometry.     

Copolymerization of Acrylamide with Sodium 2-Acrylamido-2-methylpropanesulfonate in Aqueous Salt Solutions

The kinetics of radical copolymerization of acrylamide with sodium 2-acrylamido-2-methylpropanesulfonate in water and in 1 M NaCl solutions at pH 9 and 30-50°C was studied. The kinetic data were interpreted with account of the state of the ionic groups and conformations of growing polymeric chains in the reaction mixtures.     

Copolymerization of Sodium 2-Acrylamido-2-methylpropanesulfonate with N-Vinylpyrrolidone in Water and Dimethyl Sulfoxide

The kinetics of radical copolymerization of sodium 2-acrylamido-2-methylpropanesulfonate with N-vinylpyrrolidone in water and dimethyl sulfoxide at pH 9 and 50°C in the presence of potassium peroxodisulfate initiator were studied dilatometrically.     

Effect of fire retardant on flammability of acrylamide and 2-acrylamido-2-methylpropane sodium sulfonate copolymer composites

Poly[acrylamide-co-(2-acrylamido-2-methylpropane sodium sulfonate)] superabsorbents and superabsorbent composites (SAPCs) with zinc borate and/or melamine as fire retardants were synthesized. Water absorbencies decreased inversely to added amount of fire retardant. Thermal stability of SAPC/zinc borate increases with increasing zinc borate. Incorporating melamine improved thermal stability of the SAPC until 300 °C. Flammability analysis demonstrated that wood surface coated with SAP or SAPC emulsions extended time to ignition of the wood. Peak heat release rate and total heat release are smallest in specimens coated with SAPC/30% melamine. Wood coated with SAPC incorporating 20% zinc borate/10% melamine mixture gave the longest time to ignition at 4½ min.     

Photochemistry of amphiphilic copolymers: Fluorescence spectra of copolymers of 1-(2-naphthyl)ethyl methacrylate and sodium 2-acrylamido-2-methylpropanesulfonate in solution

Amphiphilic copolymers containing 1-(2-naphthyl)ethyl ester groups were prepared and their fluorescence properties were examined. The fluorescnce spectra of the copolymers with a higher naphthyl content showed predominantly a broad monomer emission with λ_max at 340 nm in methanol, whereas a structured emission with λ_max at 344 and 362 nm was observed in aqueous solution. The former spectra changed rapidly to the latter ones upon UV irradiation. Photolysis of the copolymers and the monomeric model compound in methanol gave 2-vinylnaphthalene, whose fluorescence agreed with those of copolymers in water, together with methyl ether, alkylnaphthalenes, and other products. These results indicate that the copolymers hold vinylnaphthalene-like traps, which may emit preferentially in water because of efficient sensitization. © 1995 John Wiley & Sons, Inc.     

The binding of benzyldimethyldodecylammonium bromide to acrylamide-co-sodium-2-acrylamido-2-methylpropanesulfonate copolymers: thermodynamical and conformational aspects

The binding isotherms of benzyldimethyldodecylammonium bromide (BDDAB) to copolymers of acrylamide and sodium-2-acrylamido-2-methylpropanesulfonate (AMPS), 5 or 20% in mole ratios (AMPS5 and AMPS20, respectively), are determined by membrane ultrafiltration and analysed with the Satake–Yang formalism in terms of binding constants and cooperativities. Complexation is further investigated by steady-state fluorescence of solubilized pyrene, dynamic light scattering (DLS) and laser Doppler electrophoresis (LDE). Hydrophobic aggregates bound to AMPS20 appear similar to BDDAB free micelles, whereas those borne by AMPS5 increase in size more distinctly under the non-stoichiometric complexation mechanism. Multimolecular association and dissociation equilibria are displayed by DLS in the AMPS5 biphasic domain. Above the critical aggregation concentration, electrophoretic mobilities of the complexes initially remain unchanged by compensation of antagonistic electrostatic contributions. Upon progressive binding of micelles the charge-to-friction ratio of the polyons is reduced by condensation of the counter-ions.     

Copolymerization of sodium acrylate with new acrylamide derivatives in the presence of water-soluble salts

Copolymerization of sodium acrylate with new acrylamide derivatives was studied. The copolymerization constants r1 and r2 of the monomers and the molecular weights of the copolymers were determined.     

Molecular, conformational, and optical characteristics of poly(dodecylammonium-2-acrylamido-2-methylpropanesulfonate) in organic solvents

A number of samples of poly(dodecylammonium-2-acrylamido-2-methylpropanesulfonate)—a comb-like polymer with ionically bound side chains—are obtained by the polymerization of dodecylammonium-2-acrylamido-2-methylpropanesulfonate in an aqueous medium. The samples are obtained in a wide molecular-mass range. Molecular, hydrodynamic, and optical characteristics of the samples are determined by the methods of sedimentation-diffusion analysis, viscometry, and flow birefringence in dilute polymer solutions in chloroform and dimethyl sulfoxide containing small amounts of 0.1 M LiCl. It is shown that conformational and optical characteristics based on hydrodynamic and dynamo-optic investigations agree with the data available for acrylic and methacrylic polymers with the same lengths of side groups. In other words, the character of attachment (covalent or ionic) of long side chains to the backbone has no effect on the conformational and optical characteristics of macromolecules.