Nonionic water‐soluble polymer: Preparation, characterization, and application of poly(1‐vinyl‐2‐pyrrolidone‐<i>co</i>‐hydroxyethylmethacrylate) as a polychelatogen

et al. 2009

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Hydrophilic copolymer gels were prepared by free-radical copolymerization of 1-vinyl-2-pyrrolidone (NVP) and N-hydroxymethyl acrylamide (HMAm). The ratios of both monomers and crosslinker agent (CA) were varied, and the effect of external stimuli such as pH of the swelling media and inorganic ion interaction were investigated. The gels showed a pH-responsive behavior. The interactions of inorganic ions with the hydrophilic hydrogels were determined as a function of pH, copolymer composition, and variation of the composition crosslinking degree. Additionally, a decrease of the pH of the solution caused a decrease in the equilibrium degree of swelling of the copolymer gels. The capacity to remove several metal ions such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Cd(II), and Fe(III) in the aqueous phase was determined by using the liquid-phase polymer-based retention (LPR) technique. In addition, the copolymers and their complexes with transition metal ions were characterized by the monomer reactivity ratios by using the Kelen-Tü dö s method, elemental analysis, FTIR and 1 H-NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Based on the results of swelling and retention capacity of metal ions of poly(NVP-co-HMAm), it was concluded that the swelling and retention capacity properties of the hydrogels depends on the reaction environment's pH. This is regarded as a functional hydrogel, which could be employed as biodegradable materials for applications in agriculture chemicals and as drug delivery systems.

Section: Methodsmentioning

confidence: 99%

“…Water‐soluble polymers have also been applied to this end, and different techniques such as dialysis3, 4 and ultrafiltration5–15 have been utilized to study the interactions of metal ions with these polymers.…”

Section: Introductionmentioning

confidence: 99%

Swelling behavior and metal ion retention from aqueous solution of hydrogels based on N‐1‐vinyl‐2‐pyrrolidone and N‐hydroxymethylacrylamide

et al. 2009

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“…In the washing and enrichment methods, the metal ion retention in the cell solution is defined as where C r is the metal ion concentration in the retentate (the cell solution volume, V c , after a filtrate volume of V f has been passed) and C o is the initial metal ion concentration in the cell. The filtration factor Z , expressed in relative units, is another convenient characteristic of the process 19–23, 25 The retention depends on the polymer complex dissociation, which is generally described by a reversible reaction: In systems with inorganic ion concentrations that are relatively small with respect to the polymer concentration, only the formation of ML may be taken into account.…”

Section: Resultsmentioning

confidence: 99%

“…The copolymer contains hydroxyl group as chelating properties which are well known by their weak capability to bind metal ion. Therefore, for this copolymer a cooperative effect of different functional groups facilitating interactions with the metal ion is suggested 23…”

Section: Introductionmentioning

confidence: 99%

Metal ion retention using the ultrafiltration technique: Preparation, characterization of the water‐soluble poly(1‐vinyl‐2‐pyrrolidone‐co‐itaconic acid) and its metal complexes in aqueous solutions

et al. 2008

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Radical copolymerization of 1-vinyl-2-pyrrolidone with itaconic acid at different feed monomer ratios (75-25 mol %) were investigated. The copolymers were characterized by elemental analysis, Fourier transform infrared (FTIR), 1 H and 13 C NMR spectroscopy. The copolymer composition was determined from elemental analysis and found to be statistical copolymers. Additionally, viscosimetric measurements, molecular weight, and polydispersity have been determined. The metal complexation of poly(1-vinyl-2-pyrrolidone-co-itaconic acid) for the metal ions such as Cr(III), Co (II), Zn(II), Ni(II), Cu(II), Cd(II), and Fe(III) were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion interaction with hydrophilic polymers was determined as a function of the pH and filtration factor. Poly(1-vinyl-2-pyrrolidone-co-itaconic acid) showed a high affinity for the metal ions at pH 5 and 7. The poly(NVP-co-IA), with a copolymer composition of 29 : 71 mol % (PVA-3), presented the highest metal ion retention values, particularly at higher pHs, at which the carboxylic acid groups are nonprotonated and could easily coordinate with the metal ions. According to the interaction pattern obtained, Cr(II), Zn(II), Pb(II), and Ni(II) formed the most stable complexes at pH 7. The thermal behaviors of the copolymer and polymer metal complex were characterized using differential scanning calorimetry (DSC) and thermogravimetry techniques under nitrogen atmosphere. The copolymers present high thermal stability and do not present glass transition in DSC curves between 25 and 5008C.

“…The absorption studies for the hydrogels were carried out by placing about 0.5 g of the gel into 20 mL of defined concentration (40 mg L −1 ) of metal ion solution (Cd 2+ and Pb 2+ ) and leaving the solution under stirring. After the equilibrium was reached, the liquid‐phase polymer‐based retention (LPR) method24–31 was used to study the retention of metal ions by the hydrogel. Although the MBA‐crosslinked poly(HPMA‐ co ‐IA) and poly(HPMA‐ co ‐AC) were essentially insoluble in water, the retention of metal ions was performed in the aqueous suspension mode, thus allowing the separation of the polymer from the metal ions by continuously washing using the LPR method.…”

Section: Methodsmentioning

confidence: 99%

Novel hydrogels based on itaconic acid and citraconic acid: Synthesis, metal ion binding, and swelling behavior

et al. 2009

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Several copolymer hydrogels were prepared from radical copolymerization of 2-hydroxypropyl methacrylate (HPMA) with itaconic acid (IA) and also with citraconic acid (CA) by using different feed ratios. The copolymers were characterized by FTIR, 1 H-NMR, and 13 C-NMR spectroscopy as well as by thermal analysis. The swelling process of the different hydrogels immersed in water at different pH has been studied, and also the swelling of the hydrogels loaded with metal ions (Pb 2þ , Cd 2þ ) was investigated. The metal-binding properties were studied by using the liquid-phase polymer-based retention technique, including studies on the influence of pH on the binding process. The efficiency of these hydrogels for the recovery of metal ions in solution was determined by atomic absorption spectroscopic analysis. The thermal characteristics of these copolymers were studied by using differential scanning calorimetry and thermogravimetric analysis in nitrogen atmosphere. Accordingly, the gels loaded with metal ions showed a slight increase of the thermal decomposition temperature when compared with the pristine gels. The copolymer gel HPMA-co-CA showed a single glass transition temperature, whereas for the copolymer systems, HPMA-co-IA, only the copolymers loaded with Cd 2þ ions showed a glass transition temperature. The morphology of film produced from the copolymers was investigated by scanning electron microscopy, revealing generally smooth surfaces.