Reversible Swelling/Deswelling Characteristics of Ethylene Glycol Dimethacrylate Cross-Linked Poly(acrylic acid-<i>co</i>-sodium acrylate-<i>co</i>-acrylamide) Superabsorbents

Shukla, Neelesh Bharti; Madras, Giridhar

doi:10.1021/ie200713y

Cited by 43 publications

(31 citation statements)

References 39 publications

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“…The S eq and k s of the SAP were found to be 141.8 g=g and 4.69 h À1 , respectively. Similar first-order swelling kinetics has been observed for the poly(acrylic acid-co-sodium acrylate-co-acrylamide) [21] , hydrogels of acrylamide [22] , carboxymethyl cellulose-g-poly(acrylamideco-2-acrylamido-2-methylpropan sulfonic acid) [23] and starch-based superabsorbents [24] . Figure 4 shows the variation in the equilibrium swelling capacity of the PMALETMAC superabsorbent with the concentration of MBA.…”

Section: Swelling Of the Sapsupporting

confidence: 74%

“…The concentration difference in the mobile ions between the polymer and the swelling medium causes the osmotic pressure difference which drives the water inside the network. As a result, the SAP swells till the expansion of the network is prevented by the elastic retractive forces [20,21] . Figure 3 shows the variation in the swelling capacity of the SAP (0.5 wt% MBA) with time.…”

Section: Swelling Of the Sapmentioning

confidence: 99%

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Photo and Thermal Degradation of a Cationic Superabsorbent Polymer

Shukla

Bhagat

Madras

2013

Polymer-Plastics Technology and Engineering

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A cationic superabsorbent polymer (SAP) was synthesized by carrying out the polymerization of [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride) with N,N 0 -methylenebisacrylamide as the cross-linking agent. The SAP was subjected to degradation in dry and the equilibrium swollen state by thermo gravimetric analysis and exposure to ultraviolet radiation, respectively. The photodegradation was monitored by measuring changes in the swelling capacity and the dry weight of the SAP. The thermal degradation of the SAP occurred in three stages after the initial removal of moisture and the activation energies of the decomposition were determined. INTRODUCTIONThree-dimensional cross-linked networks of hydrophilic polymers that are able to absorb and retain liquids more than 100 times of their own weight are known as superabsorbent polymers (SAPs) [1] . The SAPs contain ionic repeat units, and could classified be as anionic, cationic, amphoteric, or zwitterionic [2] . They find applications in personal hygiene products [2] , food packaging [2] , wound healing devices [3] and water treatment [4] . Although, most of the SAPs commercially produced are anionic (based on acrylic acid and its derivatives) [2] , a wide variety of other superabsorbent polymers have been synthesized [5][6][7][8][9] . The cationic monomers have also been polymerized, either independently [10] or with anionic SAPs to obtain amphoteric SAPs [11][12][13][14][15] .The synthesis routes of the monomer-based SAPs are well established, but there are only a few studies reporting their degradation [16][17] .The SAPs constitute a significant part of domestic waste, making the degradation studies of the synthetic SAPs important. Li and Cui [16] subjected acrylic acid and acrylamide-based SAP to ultravioletinduced decomposition and quantified the degradation by measuring the weight of the SAP at the end of the degradation. Their study, although the first report of its kind, did not provide information about the changes in the swelling capacity of the SAPs during the degradation. In our previous study, we had adopted an improved technique for the photodegradation of poly (acrylic acid-co-sodium acrylate-co-acrylamide) SAPs [17] .The changes in the swelling capacity as well as the residual weights of the SAPs were measured during the degradation and a possible mechanism of the degradation of SAPs was proposed. The SAPs were found to undergo degradation in two stages. In the first stage, the network became sparse and the swelling capacity increased but the residual weight fraction was constant. The rupture of the three-dimensional network took place in the second stage, and thus both the swelling capacity and the residual weights reduced drastically.In the present study, we report the photodegradation of a cationic SAP by the earlier developed method [18] . Here we extend the study to investigate the effect of cross-link density on the photodegradation of the SAP. The cationic SAP poly([2-(methacryloyloxy)ethyl]trimethyl ammonium chloride) (PMALETMAC) was synth...

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Section: Swelling Of the Sapsupporting

confidence: 74%

Section: Swelling Of the Sapmentioning

confidence: 99%

Photo and Thermal Degradation of a Cationic Superabsorbent Polymer

Shukla

Bhagat

Madras

2013

Polymer-Plastics Technology and Engineering

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“…After the polymerization, the unreacted monomers and water were removed by adding excess of methanol, and the polymer was dried for 72 h at 80°C in a hot air oven. Further details of the polymerization are given elsewhere 32. Poly(acrylic acid‐ co ‐sodium acrylate‐ co ‐acrylamide) superabsorbents having 20, 40, 60, 80, and 100 mol % AM were named as AA/SA/AM‐1, AA/SA/AM‐2, AA/SA/AM‐3, AA/SA/AM‐4, and AM‐1, respectively.…”

Section: Methodsmentioning

confidence: 99%

Photo, thermal, and ultrasonic degradation of EGDMA‐crosslinked poly(acrylic acid‐co‐sodium acrylate‐co‐acrylamide) superabsorbents

Shukla¹,

Madras²

2011

J of Applied Polymer Sci

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Superabsorbent polymers (SAPs) based on acrylic acid (AA), sodium acrylate (SA), and acrylamide (AM) were synthesized by inverse suspension polymerization using ethylene glycol dimethacrylate as the crosslinking agent. The equilibrium swelling capacities and the rates of swelling of SAPs varied with the AM content and followed first‐order kinetics. The photodegradation of SAPs in their equilibrium swollen state was carried out by monitoring their swelling capacity and the residual weight fraction. The SAPs degraded in two stages, wherein the swelling capacity increased to a maximum and then subsequently decreased. Thermogravimetric analysis of the SAPs indicated that the copolymeric superabsorbents had intermediate thermal stability between the homopolymeric superabsorbents. The activation energies of SAPs with 0, 20, and 100 mol % AM content were determined by Kissinger method and were found to be 299, 248, and 147 kJ mol−1, respectively. The ultrasonic degradation of the superabsorbents was carried out in their equilibrium swollen state, and the change in the viscosity with ultrasonication time was used to quantify the degradation. The ultrasonic degradation of AA/SA superabsorbent was also investigated at various ultrasound intensities. The degradation rate coefficients were found to increase with the intensity of ultrasound. The ultrasonic degradation of AA/SA/AM (20% AM) was also carried out, and degradation rate was found to be more than that of the AA/SA superabsorbent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

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“…Superabsorbent polymers (SAPs) are high‐molecular‐weight three‐dimensional crosslinked networks containing ionic and neutral repeat units that can absorb water molecules and swell more than several‐fold compared to its dry state . The ionic units presenting in the network create an osmotic pressure difference between the SAP and the swelling medium . SAPs have achieved a large worldwide market, especially in agricultural, horticultural and biomedical applications.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and swelling property of superabsorbent starch grafted with acrylic acid/2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid

2017

J Sci Food Agric

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Reversible Swelling/Deswelling Characteristics of Ethylene Glycol Dimethacrylate Cross-Linked Poly(acrylic acid-co-sodium acrylate-co-acrylamide) Superabsorbents

Cited by 43 publications

References 39 publications

Photo and Thermal Degradation of a Cationic Superabsorbent Polymer

Photo and Thermal Degradation of a Cationic Superabsorbent Polymer

Photo, thermal, and ultrasonic degradation of EGDMA‐crosslinked poly(acrylic acid‐co‐sodium acrylate‐co‐acrylamide) superabsorbents

Synthesis and swelling property of superabsorbent starch grafted with acrylic acid/2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid

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