Water super absorbents based on copolymers of acrylamide with sodium acrylate

Krul, L. P.; Nareiko, E. I.; Matusevich, Yu. I.; Yakimtsova, L. B.; Matusevich, V.; Seeber, W.

doi:10.1007/pl00006832

Cited by 45 publications

(24 citation statements)

References 11 publications

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“…The optimum reaction conditions to obtain maximum water absorbency (275 g/g) were found to be: MBA 0.043 mol/L, AA 0.49 mol/L, AAm 0.13 mol/L, APS 0.02 mol/L, reaction temperature 60 o C, and reaction time 180 min. The superabsorbent hydrogels exhibited high sensitivity to pH, so that, several swelling changes of the hydrogel were observed in pH variations of a wide range (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Ionic repulsion between charged groups incorporated in the gel matrix by an external pH modulation could be assumed as the main driving force responsible for such abrupt swelling changes.…”

Section: Discussionmentioning

confidence: 99%

“…In acidic media, most carboxylate groups are protonated, so decreased repulsion of anionic groups leads to a decreased swelling ratio. At higher pHs (3)(4)(5)(6)(7)(8), some carboxylate groups are ionized and the electrostatic repulsion between carboxylate groups causes an enhancement of the swelling capacity. The reason of the swelling loss for the highly basic solutions is the charge screening effect of excess Na + in the swelling media, which shield the carboxylate anions and prevent effective anion-anion repulsion.…”

Section: Effect Of Ph On Equilibrium Swellingmentioning

confidence: 99%

“…Nowadays, the worldwide production of SAPs is more than one million tons in a year. Hence, synthesis and characterization of superabsorbent hydrogels is the main goal of the several research groups in the world [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

Pourjavadi¹,

Sadeghi²,

Hashemi³

et al. 2006

E-Polymers

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Abstract:In this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers was also investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1.0 and 13.0. It showed a reversible pH-responsive behavior at pHs 2.0 and 7.0. This on-off switching behavior makes the synthesized hydrogels an excellent candidate for controlled delivery of bioactive agents. Finally, the swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated.

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Section: Discussionmentioning

confidence: 99%

Section: Effect Of Ph On Equilibrium Swellingmentioning

confidence: 99%

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Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

Pourjavadi¹,

Sadeghi²,

Hashemi³

et al. 2006

E-Polymers

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show abstract

“…Due to unique properties of SAPs, these polymers was synthesized and characterized by the several research groups in the world [2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and swelling properties of a poly(vinyl alcohol)-based superabsorbing hydrogel

Hosseinzadeh

2013

10.5267/j.ccl

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Superabsorbent hydrogels based on poly(vinyl alcohol) were prepared by a crosslinking technique using glutaraldehyde as a crosslinker. The hydrogel structure was confirmed using scanning electron microscopy (SEM). Results from SEM observation showed a porous structure with smooth surface morphology of the hydrogel. We have systematically optimized the certain variables of hydrogel synthesis (i.e. the crosslinker concentration, poly(vinyl alcohol) content, time and temperature of crosslinking reaction) to achieve a hydrogel with maximum water absorbency. It was concluded that under the optimized conditions, maximum capacity of swelling in distilled water was equal to 231 g/g. The absorbency under load (AUL) of hydrogels was also measured. In addition, swelling ratio in various salt solutions was determined and the hydrogels exhibited salt-sensitivity properties.

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“…[2][3][4] Hence, synthesis and investigation of specific and new superabsorbent hydrogels with high absorbency, mechanical strength and initial absorption rate, has been the goal of several research groups in the past decades. [5][6][7][8] Acrylic-based SAPs have been widely studied and applied in different biomedical fields because of their good swelling behaviors and chemical stability. 9 Most of ionic hydrogels sometimes undergo a volume phase transition in response to a little change in surrounding conditions such as heat, pH, electric field, chemical environments, etc.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Properties of Partially Hydrolyzed Acrylonitrile-co-Acrylamide Superabsorbent Hydrogel

Pourjavadi¹,

Hosseinzadeh²

2010

Bulletin of the Korean Chemical Society

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In this work, a novel method to synthesis of an acrylic superabsorbent hydrogel was reported. In the two stage hydrogel synthesis, first copolymerization reaction of acrylonitrile (AN) and acrylamide (AM) monomers using ammonium persulfate (APS) as a free radical initiator was performed. In the second stage, the resulted copolymer was hydrolyzed to produce carboxamide and carboxylate groups followed by in situ crosslinking of the polyacrylonitrile chains. The results from FTIR spectroscopy and the dark red-yellow color change show that the copolymerization, alkaline hydrolysis and crosslinking reactions have been do take place. Scanning electron microscopy (SEM) verifies that the synthesized hydrogels have a porous structure. The results of Brunauer-Emmett-Teller (BET) analysis showed that the average pore diameter of the synthesized hydrogel was 13.9 nm. The synthetic parameters affecting on swelling capacity of the hydrogel, such as AM/AN weight ratio and hydrolysis time and temperature, were systematically optimized to achieve maximum swelling capacity (330 g/g). The swollen gel strength of the synthesized hydrogels was evaluated via viscoelastic measurements. The results indicated that superabsorbent polymers with high water absorbency were accompanied by low gel strength. The swelling of superabsorbent hydrogels was also measured in various solutions with pH values ranging from 1 to 13. Also, the pH reversibility and on-off switching behavior makes the hydrogel as a good candidate for controlled delivery of bioactive agents. Finally, the swelling of synthesized hydrogels with various particle sizes obey second order kinetics.

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Water super absorbents based on copolymers of acrylamide with sodium acrylate

Cited by 45 publications

References 11 publications

Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

Synthesis and absorbency of gelatin-graft-poly(sodium acrylate-co-acrylamide) superabsorbent hydrogel with saltand pH-responsiveness properties

Synthesis and swelling properties of a poly(vinyl alcohol)-based superabsorbing hydrogel

Synthesis and Properties of Partially Hydrolyzed Acrylonitrile-co-Acrylamide Superabsorbent Hydrogel

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