Studies of crosslinked poly(AM-MSAS-AA) gels. II. Effects of polymerization conditions on the water absorbency

Zhou, Wen; Yao, Ke Jun; Kurth, Mark J.

doi:10.1002/(sici)1097-4628(19970502)64:5<1009::aid-app19>3.0.co;2-z

Cited by 21 publications

(10 citation statements)

References 6 publications

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“…The degree of neutralization of AAc was 40%. Zhou et al [12] have prepared a series of novel superabsorbent copolymers based on Acrylamide (AAm), sodium methallylsulfonate, sodium acrylate in the presence of N,N 0 -methylenebisacrylamide (NMBA) as cross-linker and Potassium per sulphate (KPS)=N,N, N 0 ,N 0 -tetramethylenediamine (TMEDA) as the redox initiator. The ionic groups in the polymer network significantly increase the equilibrium swelling.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Poly (Acrylamide-co-Acrylic Acid) based Superabsorbent Hydrogels: Study of Network Parameters and Swelling Behaviour

Tomar

Gupta

Singhal

et al. 2007

Polymer-Plastics Technology and Engineering

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This article investigates the synthesis of superabsorbent hydrogels (SAHs) based on acrylamide and acrylic acid by solution polymerization in the presence of N,N 0 -methylenebisacrylamide (NMBA) as a cross-linker and potassium per sulphate as initiator. In this work the acrylamide content was varied in a large range of 30-70% (mole of total monomer) in feed, in order to study its effect on swelling behavior. The results indicate that when acrylamide content present in the hydrogels was increased from 17.23-35.85% (mole of the total monomer); then equilibrium water absorbency also increased from 276-573 (g water/g sample). But when acrylamide content was further increased from 35.85-50.24%, then equilibrium water absorbency abruptly decreased. The equilibrium water absorbency of various copolymeric hydrogels was also investigated in different concentration of saline solutions. The effect of SAHs on growth of seeds of lentil was also studied. The hydrogels were also characterized by fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM); and network parameters such as average molecular weight between cross-links (Mc) and cross-link density (q) were determined to explain the swelling behavior.

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Section: Introductionmentioning

confidence: 99%

Synthesis of Poly (Acrylamide-co-Acrylic Acid) based Superabsorbent Hydrogels: Study of Network Parameters and Swelling Behaviour

Tomar

Gupta

Singhal

et al. 2007

Polymer-Plastics Technology and Engineering

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“…1,2 The swelling equilibrium of many different gels depends inversely on the total comonomers concen-tration (C T ) and the crosslinker concentration (c xl ) employed in the polymerization feed mixture. [3][4][5][6][7][8] Theoretical support of these empirical relationships comes from scaling laws relating S and the average number of monomer units between two connected crosslinks, [9][10][11][12][13] N, and from less frequent laws relating N with the comonomers (C T ) and crosslinker (c xl ) concentrations in the feed. 3,6 The simplest model of the dependence of N (N IN for this model) on C T and c xl considers that for ideal polymer networks (IN), without defects, with knots functionality f, is 10 N IN ¼ 2C T /fc xl .…”

Section: Introductionmentioning

confidence: 99%

Correlation of swelling and crosslinking density with the composition of the reacting mixture employed in radical crosslinking copolymerization

Pacios¹,

Molina²,

Gómez-Antón³

et al. 2006

J of Applied Polymer Sci

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This article reports the scaling laws relating the synthesis conditions with the crosslinking density (νe) and swelling degree (S) of poly(N‐vinylimidazole) hydrogels (PVI) prepared by radical crosslinking copolymerization in aqueous solution, with N,N′‐methylene bisacrylamide (BA) as crosslinker. Multiple linear regression of νe versus BA concentration ([BA]) and total comonomers concentration (CT) in double log scale render the scaling law νe ∼ C italicT0.81 × [BA]1.04 as comparable to that predicted by the model of polymer network with pendant vinyl groups (νe ∼ CT × [BA]), and showing inverse dependence on CT to that expected, following from stoichiometry, for an ideal network (νe ∼ 2[BA]/CT). S scales with νe through a solvent‐dependent exponent ranging from −0.46 to −0.54, only slightly over the value predicted by the Flory–Rehner theory (−0.6) or the blob's model by de Gennes (−0.5 to −0.8). Finally, the scaling law of S with the composition of the reacting mixture is also solvent‐dependent and it seems to result not only from the dependence of νe on CT and [BA] but also from that of v2r, the polymer volume fraction in the reference state, and χ, the polymer–solvent interaction parameter. Models used seem to overestimate the contribution of entanglements to the effective crosslinking density of PVI. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 263–269, 2007

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“…17 The results in this study are in agreement with previous reports that the initiation capability of the peroxydisulfate/TMEDA system can be severely limited under acidic conditions owing to the protonation of TMEDA. 18,19 Therefore, the reduction in gel yield was observed only for copolymerization of MA-inulin with AAc, but not for copolymerization with HEMA ( Fig. 3).…”

Section: Discussionmentioning

confidence: 92%

Synthesis of pH‐sensitive inulin hydrogels and characterization of their swelling properties

Chiu

Hsu

Lin

2002

J. Biomed. Mater. Res.

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Abstract:In this study, pH-responsive inulin hydrogels were prepared by radical copolymerization of methacrylated inulin (MA-inulin) with acrylic acid (AAc) in aqueous solution using ammonium peroxydisulfate (APS) and N,N,NЈ,NЈ-tetramethylethylenediamine (TMEDA) as an initiation system. The AAc content in hydrogels was evaluated by FTIR spectroscopy. The covalent bridging of AAc among MA moieties of MA-inulins was observed by a significant increase in the effective network density of hydrogels and further confirmed by TGA studies. While, at a low content of AAc, the hydration of hydrogels at pH 7.4 decreased owing to the increased crosslinking density, the swelling subsequently increased with further increasing AAc as a consequence of the increased ionic osmotic pressure within hydrogels. The change in swelling of hydrogels in response to pH change between 7.4 and 2.2 was therefore enlarged when the AAc content increased.

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Studies of crosslinked poly(AM-MSAS-AA) gels. II. Effects of polymerization conditions on the water absorbency

Cited by 21 publications

References 6 publications

Synthesis of Poly (Acrylamide-co-Acrylic Acid) based Superabsorbent Hydrogels: Study of Network Parameters and Swelling Behaviour

Synthesis of Poly (Acrylamide-co-Acrylic Acid) based Superabsorbent Hydrogels: Study of Network Parameters and Swelling Behaviour

Correlation of swelling and crosslinking density with the composition of the reacting mixture employed in radical crosslinking copolymerization

Synthesis of pH‐sensitive inulin hydrogels and characterization of their swelling properties

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