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Sodium Acrylate (sodium + acrylate)
Selected AbstractsSynthesis and Properties of a Superabsorbent Polymer Prepared by Copolymerization of Sodium Acrylate with Sodium 1-(Acryloyloxy)propan-2-yl PhosphateMACROMOLECULAR REACTION ENGINEERING, Issue 2 2007Zhenbin Chen Abstract A novel monomer, 1-(acryloyloxy)propan-2-yl phosphoryl dichloride, was synthesized and characterized in this work. Thereafter, the monomer was neutralized with sodium hydroxide and copolymerized with sodium acrylate to obtain a superabsorbent polymer. The superabsorbent polymer was then modified to improve its swelling properties (i.e., the water absorbency under load, the hydrogel strength, the resilience and the dispersion). Both single factor and orthogonal design experiments were adopted to obtain optimal conditions. The superabsorbent polymer prepared under the optimal conditions showed improved water absorbency in physiological saline [17 g,·,g,1 under load (P,=,2,×,103 Pa) and 65 g,·,g,1 at atmospheric pressure] and other swelling properties, such as hydrogel strength, resilience and dispersion, also improved. [source] Preparation and characteristic of electric stimuli responsive hydrogel composed of polyvinyl alcohol/poly (sodium maleate- co -sodium acrylate)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Yi Gao Abstract Maleic anhydride was used to preparare polyvinyl alcohol/poly (sodium maleate- co -sodium acrylate) hydrogels (PVA/poly(SMA-SAA)) by a repeated frost-defrost process because of its higher charge density and potential electric stimuli sensitivity. The bending angle was measured in a noncontact electric field using carbon as plate electrodes. It was found that the bending angle was dependent on various factors, including composition of hydrogel, concentration of NaCl solution, types of electrolyte solution, and electric voltage. It exhibited that the bending angle increased when the concentration of NaCl solutions and the electric voltages increased. An abnormal bending direction was observed, and it was affected not only by the kinds of hydrogels, but also by the exterior variations. The hydrogel showed good reversibility in on-off electric field and could be a candidate for practical application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Preparation and polymerization of a water-soluble, nonbonding crosslinking agent for a mechanically crosslinked hydrogelJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2005Masataka Kubo Abstract A novel water-soluble cyclic macromonomer based on a cyclic potassium polyacrylate was prepared. The radical polymerization of acrylamide in the presence of the cyclic macromonomer was carried out to obtain a mechanically crosslinked polyacrylamide. The terpolymerization of acrylamide, sodium acrylate, and the cyclic macromonomer gave a mechanically crosslinked polyelectrolyte with high swellability. The mechanically crosslinked polyelectrolyte exhibited large volume shrinkage in a water solution of Cu(II) salt. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5032,5040, 2005 [source] Salt-Induced Micelle Behavior of Poly(sodium acrylate)- block -Poly(N -isopropylacrylamide) by ATRPMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 4 2008Shuping Jin Abstract Temperature- and pH-sensitive diblock copolymers PAANa75 - b -PNIPAMm are prepared by a combination of reverse and normal ATRP in aqueous solution at room temperature. The block copolymer is also stimuli-sensitive with respect to salt in the aqueous solution, and forms spherical star-like micelles with a PNIPAM core and an expanded PAANa shell for PAANa75 - b -PNIPAM76 as well as spherical crew-out micelles with a PNIPAM core for PAANa75 - b -PNIPAM5110, as indicated by a fluorescence probe technique and TEM. A three-stage model mechanism of phase transition driven by small molecule salt is proposed. [source] SAXS from Four-Arm Polyelectrolyte Stars in Semi-Dilute SolutionsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 1 2003Delphine Moinard Abstract We have performed small-angle X-ray scattering experiments on semi-dilute solutions of highly charged star polyelectrolytes. Poly(sodium acrylate) (PANa) and poly(cesium acrylate) (PACs) stars with four arms were successfully synthesized by a combination of atom transfer radical polymerization and chemical modifications. Over a wide range of polyelectrolyte concentration Cp, these two systems as well as their equivalent linear polyelectrolytes were investigated at different ionic strengths. Scattering experiments show the existence of a scattering peak denoted as qmax, which disappears with the addition of a simple electrolyte, evidencing the electrostatic character of the interactions. We have also studied the effect of the charge parameter and the nature of the counterion (Na and Cs) on the scattering properties of these star polyelectrolytes. In the case of PACs, qmax scales with the polyelectrolyte concentration as Cp1/2 over the whole range of studied concentrations, whereas it scales as Cp1/2 (for Cp,<,45 mg,·,ml,1) and Cp1/4 (for Cp,>,45 mg,·,ml,1) in the case of PANa. Variation of qmax as a function of polyelectrolyte concentration Cp for PA1Cs (,) and PA2Cs (,) stars (error bars are indicated). [source] Fabrication of Silver Nanoparticles in Hydrogel Networks,MACROMOLECULAR RAPID COMMUNICATIONS, Issue 16 2006Y. Murali Mohan Abstract Summary: This paper describes a simple and facile approach to fabricate well dispersed silver nanoparticles (AgNPs) in poly[N -isopropylacrylamide- co -(sodium acrylate)] hydrogels. The silver nanoparticles formed are spherical in shape with a narrow size distribution in the hydrogel networks in which the nanoparticles are stabilized by the polymer network. Uniformly dispersed silver nanoparticles were obtained with poly[N -isopropylacrylamide- co -[sodium acrylate)] hydrogels, whereas a poly(N -isopropylacrylamide)/poly(sodium acrylate) IPN gel showed aggregated nanoparticles. It is demonstrated that the hydrogel network structure determines the size and shape of the nanoparticles. These particles are more stable in the gel networks compared to other reduction methods. The hydrogel/silver nanohybrids were well characterized by XRD, UV-vis spectrometry, scanning electron microscopy and transmission electron microscopy. Schematic representation of the preparation of Ag nanoparticles in hydrogel networks. [source] Synthesis and Properties of a Superabsorbent Polymer Prepared by Copolymerization of Sodium Acrylate with Sodium 1-(Acryloyloxy)propan-2-yl PhosphateMACROMOLECULAR REACTION ENGINEERING, Issue 2 2007Zhenbin Chen Abstract A novel monomer, 1-(acryloyloxy)propan-2-yl phosphoryl dichloride, was synthesized and characterized in this work. Thereafter, the monomer was neutralized with sodium hydroxide and copolymerized with sodium acrylate to obtain a superabsorbent polymer. The superabsorbent polymer was then modified to improve its swelling properties (i.e., the water absorbency under load, the hydrogel strength, the resilience and the dispersion). Both single factor and orthogonal design experiments were adopted to obtain optimal conditions. The superabsorbent polymer prepared under the optimal conditions showed improved water absorbency in physiological saline [17 g,·,g,1 under load (P,=,2,×,103 Pa) and 65 g,·,g,1 at atmospheric pressure] and other swelling properties, such as hydrogel strength, resilience and dispersion, also improved. [source] Investigation of binary polymer/surfactant or ternary polymer/surfactant/Cu2+ complexes in aqueous solution through Nile red probingPOLYMER INTERNATIONAL, Issue 8 2010Zacharoula Iatridi Abstract The optical properties (absorption and emission) of Nile red have been widely used for staining or probing purposes in diverse aqueous systems. However, the applications of Nile red for the determination of the critical aggregation concentration of polymer/surfactant complexes or for the investigation of ternary polymer/surfactant/Cu2+ systems are very limited. The interactions between anionic polyelectrolytes and the oppositely charged surfactant N,N,N,N -dodecyltrimethylammonium chloride were investigated in dilute aqueous solution, exploiting the optical properties of Nile red. It is shown that the emission properties of Nile red present better sensitivity than its absorption properties, concerning the detection of the hydrophobic polymer/surfactant complexes formed in aqueous solution. Moreover, it is found that the formation of ternary polymer/surfactant/Cu2+ complexes leads to a pronounced quenching of the luminescence of Nile red. The corresponding Stern,Volmer plots indicate that quenching is more favourable when coordination of Cu2+ ions with poly(sodium acrylate) takes place, as compared to simple electrostatic binding of these ions with poly(sodium styrene sulfonate). Nile red is a sensitive and accurate tool, as an alternative to pyrene, for the characterization of binary polymer/surfactant complexes or for obtaining information on the local arrangement of ternary polymer/surfactant/Cu2+ systems in aqueous solution. Copyright © 2010 Society of Chemical Industry [source] Amphiphilic polyelectrolyte for stabilization of multiple emulsions,POLYMER INTERNATIONAL, Issue 4 2003Fanny Michaut Abstract Multiple emulsions are complex thermodynamically unstable systems where both types of emulsion coexist. We investigated the stability behaviour of water-in-oil-in-water (W/O/W) emulsions formulated with a hydrophobically modified poly(sodium acrylate) emulsifier at the outer interface and a monomeric surfactant (span 80) at the inner interface. Their stability was tested through release kinetics of a marker (NaCl) initially encapsulated in the aqueous droplets, and by rheology. Slow release rates and remarkably long shelf-life were obtained compared to typical multiple emulsions stabilized by two commonly used surfactants (span 80 and tween 20). In addition, we prepared stable highly concentrated multiple emulsions. Their rheological behaviour indicated that the internal interface was essentially covered with span 80. Thus, transportation of the polymer across the oil phase is limited, which in turn explains, at least partially, the stability improvement in the presence of the polymeric emulsifier. Finally, the long lifetime of the emulsions allowed study by diffusing wave spectroscopy of the interactions between the droplets and the globule surface which are important for understanding the destruction mechanisms of multiple emulsions. © 2003 Society of Chemical Industry [source] Synthesis of novel superabsorbing copolymers for agricultural and horticultural applicationsPOLYMER INTERNATIONAL, Issue 8 2001K Mohana Raju Abstract A series of novel superabsorbent copolymers (SAPs) based on monomers acrylamide, calcium acrylate and sodium acrylate have been prepared using ammonium persulfate as initiator and N,N -methylene-bis-acrylamide (MBA) as crosslinking agent; the monomer concentration, MBA concentration and initiator concentration were varied. The experimental results show that the SAPs have good absorbency both in water and NaCl solutions. The copolymers were characterized by IR spectroscopy. Water retention in soil is enhanced by use of these superabsorbents. The effect of SAPs on the growth of bean plants is reported. SAPs may be of use as water management materials for agricultural and horticultural purposes in desert and drought-prone areas. © 2001 Society of Chemical Industry [source] Synthesis of the hydrophobic,hydrophilic macroporous poly divinylbenzene/poly(sodium acrylate) IPN resin and adsorption performance for berberinePOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 12 2009Guqing Xiao Abstract The macroporous polydivinylbenzene/poly(methyl acrylate) interpenetrating polymer network (PDVB/PMA IPN) was prepared by the sequential suspension polymerization method, and was modified to be hydrophobic,hydrophilic macroporous polydivinylbenzene/poly (sodium acrylate) IPN (PDVB/PNaA IPN) by converting the PMA to PNaA under the condition of base. The effects of different mass ratio of the two networks and different cross-linking degree of the second network on the pore structure and adsorption capacity of PDVB/PNaA IPN resin were studied. The PDVB/PNaA IPN resin whose adsorption quantity is the biggest was chosen to study further. The pore structure, the weak acid exchange capacity, the water retention capacity, and the swelling ability of PDVB/PNaA IPN resin were measured. The study focused on the adsorption isotherms of berberine at different temperatures. Isosteric adsorption enthalpy, adsorption Gibbs free energies can be calculated according to thermodynamic functions. The results show that the saturated adsorption quantity of berberine is up to 109.4,mg,ml,1 (wet resin) by the way of dynamic adsorption and desorption experiment. The resin could be reused by the mixture with 0.5% sodium chloride and 80% ethanol. On the one hand the hydrophobic PDVB in the PDVB/PNaA IPN resin has the ability of adsorption using ,,, interaction, and on the other hand the hydrophilic PNaA in the PDVB/PNaA IPN resin has the ability of adsorption using ion exchange interaction. An important conclusion can be drawn that the PDVB/PNaA IPN resin has a promising application prospect in extracting and separating quaternary ammonium type alkaloids such as berberine. Copyright © 2009 John Wiley & Sons, Ltd. [source] Preparation and properties of diatomite composite superabsorbentPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3 2007Xiaohua Qi Abstract A novel diatomite composite superabsorbent was synthesized by solution polymerization of partially neutralized acrylic acid and diatomite, using N,N,-methylenebisacrylamide as a crosslinking agent and hydrogen peroxide and L -ascorbic acid as a redox initial system. The influences of some reaction conditions, such as diatomite content, neutralization degree of acrylic acid, amount of initiator, amount of crosslinking agent, monomer concentration, and the reaction temperature on swelling characteristic were investigated. The water absorbency of the sample prepared at optimum conditions was 99,g/g in 0.9,wt% NaCl solution. The results of swelling rate measurement showed that diatomite composite superabsorbent had better swelling rate than that of poly(sodium acrylate) prepared in the same conditions. Other properties, i.e. water retention, reswelling ability and resistance to salt, were also examined. Copyright © 2007 John Wiley & Sons, Ltd. [source] Preparation of a multifunctional bacterial fertilizer by living azospirillum simplex cells immobilized on poly(sodium acrylate)POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1-2 2004Yun-Pu Wang Abstract A living azospirillum simplex cell (LASSC) was immobilized on poly(sodium acrylate) (PSA). The method of preparation of the immobilized-cell (LASSC-PSA) was studied. LASSC was immobilized on PSA in an immobilizing medium of Na2HPO4,·,12H2O-NaH2PO4,·,2H2O (pH 7.0) buffer, sterile water, a solution of NaCl (0.85% m/m), cultured medium (pH 7.0), respectively. The desorption capacity of LASSC on LASSC-PSA in sterile water was measured and when the Na2HPO4,·,12H2O-NaH2PO4,·,2H2O (pH 7.0) buffer served as the immobilizing medium, the desorption capacity of LASSC on LASSC-PSA was the highest. The rate (m/m) of PSA and LASSC (wet weight) also affected considerably the desorption capacity of LASSC on LASSC-PSA in sterile water, and the best rate was 1,:,0.5. The desorption capacity of LASSC on LASSC-PSA was 50% of that at the beginning and that was still 109,cfu/g on storage for 5 months when the rate (m/m) of PSA and LASSC (wet weight) was 1,:,0.5, using Na2HPO4,·,12H2O-NaH2PO4,·,2H2O (pH 7.0) buffer as immobilizing medium. Copyright © 2004 John Wiley & Sons, Ltd. [source] Hydrophobically modified polyelectrolytes II: synthesis and characterization of poly(acrylic acid-co-alkyl acrylate)POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11-12 2001Dong-qing Zhuang Abstract A series of hydrophobically modified poly(acrylic acid)(RH -PAA) were synthesized by solution copolymerization of acrylic acid with a small amount of alkyl acrylate (alkyl chain with a length of 8, 12, 14, 16, 18) and their solution properties were also systematically studied. It was found that the random distribution of alkyl acrylate along the polymeric backbone imparts these new materials pronounced associating ability in aqueous solution and the associating abilities vary with the chain length of the hydrophobic groups. In dilute solution, intramolecular association is observed from the intrinsic viscosity and the dependence of the intrinsic viscosity on chain length and ionic strength is also discussed. In semiconcentration solution, the modified polymers exhibit viscosities of several orders of magnitude higher than the unmodified poly(sodium acrylate) due to the strong intermolecular hydrophobic association. And the viscosifying effects become more significant with the increasing length of the alkyl chain. The copolymer solutions are highly pseudoplastic. Evidences for the hydrophobically associating interaction between hydrocarbon groups are provided by the dependence of the Brookfield viscosity on concentration, temperature, shear rate, ionic strength and pH. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||