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Superabsorbent Polymers (superabsorbent + polymer)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Synthesis and Properties of a Superabsorbent Polymer Prepared by Copolymerization of Sodium Acrylate with Sodium 1-(Acryloyloxy)propan-2-yl Phosphate

MACROMOLECULAR REACTION ENGINEERING, Issue 2 2007
Zhenbin 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]

Molecular Design of Superabsorbent Polymers for Organic Solvents by Crosslinked Lipophilic Polyelectrolytes,

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2008
Toshikazu Ono
Abstract Molecular design of lipophilic polyelectrolyte gels as superabsorbent polymers that exhibit a high degree of swelling in less-polar and nonpolar organic solvents is demonstrated. A small amount of tetraalkylammonium tetraphenylborate with long alkyl chains as a lipopholic ion pair is incorporated into crosslinked polyacrylates with variable alkyl chain lengths to provide novel lipophilic polyelectrolyte gels. Their swelling degree becomes more than 100 times as much as their dried weights in various organic solvents. The high effectiveness of the swellable solvents shifts to the polar ones by decreasing the length of the alkyl chain. Swelling or collapsing of the lipophilic polyelectrolyte gels originates from both incompatibility of the polymer chains in the media and dissociation of ionic groups. Thus, a unique superabsorbency is observed when the polymer chains have good compatibility with the solvents and the solvents have relatively high polarities enough to dissociate the ionic groups. By varying the polarity of the neutral monomer in these polyelectrolyte gels, the design of gels that can absorb solvents of nearly any polarity is demonstrated. [source]

Synthesis and properties of carboxymethyl cellulose- graft -poly(acrylic acid- co -acrylamide) as a novel cellulose-based superabsorbent

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007
Aili Suo
Abstract A new cellulose-based superabsorbent polymer, carboxymethyl cellulose- graft -poly(acrylic acid- co -acrylamide), was prepared by the free-radical grafting solution polymerization of acrylic acid (AA) and acrylamide (AM) monomers onto carboxymethyl cellulose (CMC) in the presence of N,N,-methylenebisacrylamide as a crosslinker with a redox couple of potassium persulfate and sodium metabisulfite as an initiator. The influences of reaction variables such as the initiator content, crosslinker content, bath temperature, molar ratio of AA to AM, and weight ratio of the monomers to CMC on the water absorbency of the carboxymethylcellulose- graft -poly(acrylic acid- co -acrylamide) copolymer were investigated. The copolymer's structures were characterized with Fourier transform infrared spectroscopy. The optimum reaction conditions were obtained as follows: the bath temperature was 50°C; the molar ratio of AA to AM was 3 : 1; the mass ratio of the monomers to CMC was 4 : 1; and the weight percentages of the crosslinker and initiator with respect to the monomers were 0.75 and 1%, respectively. The maximum water absorbency of the optimized product was 920 g/g for distilled water and 85 g/g for a 0.9 wt % aqueous NaCl solution. In addition, the superabsorbent possessed good water retention and salt resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1382,1388, 2007 [source]

Synthesis and Properties of a Superabsorbent Polymer Prepared by Copolymerization of Sodium Acrylate with Sodium 1-(Acryloyloxy)propan-2-yl Phosphate

MACROMOLECULAR REACTION ENGINEERING, Issue 2 2007
Zhenbin 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]

Molecular Design of Superabsorbent Polymers for Organic Solvents by Crosslinked Lipophilic Polyelectrolytes,

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2008
Toshikazu Ono
Abstract Molecular design of lipophilic polyelectrolyte gels as superabsorbent polymers that exhibit a high degree of swelling in less-polar and nonpolar organic solvents is demonstrated. A small amount of tetraalkylammonium tetraphenylborate with long alkyl chains as a lipopholic ion pair is incorporated into crosslinked polyacrylates with variable alkyl chain lengths to provide novel lipophilic polyelectrolyte gels. Their swelling degree becomes more than 100 times as much as their dried weights in various organic solvents. The high effectiveness of the swellable solvents shifts to the polar ones by decreasing the length of the alkyl chain. Swelling or collapsing of the lipophilic polyelectrolyte gels originates from both incompatibility of the polymer chains in the media and dissociation of ionic groups. Thus, a unique superabsorbency is observed when the polymer chains have good compatibility with the solvents and the solvents have relatively high polarities enough to dissociate the ionic groups. By varying the polarity of the neutral monomer in these polyelectrolyte gels, the design of gels that can absorb solvents of nearly any polarity is demonstrated. [source]

Characterization and biodegradability of amphoteric superabsorbent polymers

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008
Dan Wang
Abstract Novel amphoteric superabsorbent polymers (SAPs) based on carboxymethyl cellulose, acrylic acid, acrylamide, and [2-(methylacryloyloxy)ethyl]trimethylammonium chloride were prepared by inverse suspension copolymerization. The SAPs were characterized by Fourier transforms infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The absorbency or swelling behaviors in deionized water, saline solutions, and pH value solutions were investigated. Experimental results indicate that the absorbency in various solutions decreases with an increase of the ion concentration, which was attributed to osmotic pressure of water and ions between the polymeric gel and the external solutions. Biodegradability of the amphoteric SAPs was also reported. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]