Synthesis and metal ion uptake properties of water-insoluble functional copolymers: removal of metal ions with environmental impact

New adsorbents, poly(N-(3-dimethylamino)propylmethacrylamide-co-acrylic acid), P(NDAPA-AA), poly(N-(3-dimethylamino)propylmethacrylamide-co-4-acryloylmorpholine), P(NDAPA-AMo), and poly(N-(3-dimethylamino)propylmethacrylamide-co-2-acrylamidoglycolic acid), P(NDAPA-AAg) were obtained by radical polymerization and characterized by Fourier transform infrared spectroscopy and thermogravimetry. The uptake metal ion properties of cadmium(II), zinc(II), lead(II), mercury(II), and chromium(III) were examined by batch-equilibrium technique with respect to the initial pH, temperature, and initial metal ion concentration under competitive and noncompetitive conditions. Maximum adsorption capacity was determined. Acid and basic regeneration was tested in order to restore the adsorbent to initial conditions. Resins P(NDAPA-AA) and P(NDAPA-AMo) showed a great ability to retain Cr(III), whereas P(NDAPA-co-AAg) to retain Hg(II).     

Poly(N-hydroxymethyl acrylamide-co-acrylic acid) and poly(N-hydroxymethyl acrylamide-co-acrylamidoglycolic acid): synthesis, characterization, and metal ion removal properties

Macroreticular chelating resins containing carboxylic groups, poly(N-hydroxymethyl acrylamide-co-acrylic acid) P(HMA-co-AA) and poly(N-hydroxymethyl acrylamide-co-2-acrylamido glycolic acid) P(HMA-co-AGA) were synthesized by solution radical polymerization with ammonium persulfate as initiator and N,N′-methylene-bis-acrylamide as cross-linking reagent. The polymerization yield was 98.9 and 91.9% for P(HMA-co-AA) and P(HMA-co-AGA), respectively. The retention properties were studied under competitive and noncompetitive conditions by batch equilibrium procedure for the following metal ions: Cd(II), Cr(III), Zn(II), Pb(II), and Hg(II). The effects of pH, time, temperature, and initial ion concentration on adsorption were investigated. The resins showed a significant ability to retain Pb(II), greater than 79%, at pH 5.     

Water‐soluble copolymers of 1‐vinyl‐2‐pyrrolidone and acrylamide derivatives: synthesis,characterization, and metal binding capability studied by liquid‐phase polymer‐based retention technique

Radical copolymerizations of 1‐vinyl‐2‐pyrrolidone with acrylamide and N,N′‐dimethylacrylamide at different feed ratios were investigated. The copolymers were characterized by Fourier transform infrared spectroscopy, ¹H NMR, and ¹³C NMR spectroscopy. The copolymer composition was determined from the ¹H NMR spectra and found to be statistical. The metal complexation of poly(acrylamide‐co‐1‐vinyl‐2‐pyrrolidone) and poly(N,N′‐dimethylacrylamide‐co‐1‐vinyl‐2‐pyrrolidone) for the metal ions Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Fe(III), and Cr(III) were investigated in an aqueous phase. The liquid‐phase polymer‐based retention method is based on the retention of inorganic ions by soluble polymers in a membrane filtration cell and subsequent separation of low‐molecular compounds from the polymer complex formed. The metal ion interaction with the hydrophilic polymers was determined as a function of the pH and the filtration factor. Poly(N,N‐dimethylacrylamide‐co‐1‐vinyl‐2‐pyrrolidone) showed a higher affinity for the metal ions than poly(acrylamide‐co‐1‐vinyl‐2‐pyrrolidone). According to the interaction pattern obtained, Cr(III) and Cu(II) formed the most stable complexes at pH 7. Pb(II) and Zn(II) were not retained. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 741–750, 1999     

Synthesis of water‐insoluble functional copolymers containing amide,amine, and carboxylic acid groups and their metal‐ion‐uptake properties

The crosslinked poly[N‐(3‐dimethylamino)propylmethacrylamide] [P(NDAPA)] and poly[N‐(3‐dimethylamino)propylmethacrylamide‐co‐acrylic acid] [P(NDAPA‐co‐AA)] were synthesized by radical polymerization. The resins were completely insoluble in water. The metal‐ion‐uptake properties were studied by a batch equilibrium procedure for the following metal ions: silver(I), copper(II), cadmium(II), zinc(II), lead(II), mercury(II), chromium(III), and aluminum(III). The P(NDAPA‐co‐AA) resin showed a lower metal‐ion affinity than P(NDAPA), except for Hg(II), which was retained at 71% at pH 2. At pH 5, the resin showed a higher affinity for Pb(II) (80%) and Cu(II) (60%), but its affinity was very low for Zn(II) and Cr(III). The polymer ligand–metal‐ion equilibrium was achieved during the first 20 min. By changing the pH, we found it possible to remove between 60 and 70% of Cd(II) and Zn(II) ions with (1M, 4M) HClO₄ and (1M, 4M) HNO₃. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5232–5239, 2006     

Thermal properties of poly(N-maleyl glycine), poly(N-maleyl glycine-co-acrylic acid), and their metal complexes

The thermal properties of two water-soluble polymers; poly(N-maleyl glycine) and poly(N-maleyl glycine-co-acrylic acid) as well as their metal complexes with Co(II), Zn(II), Ni(II), Cu(II), Fe(III), Cd(II), Pb(II), and Hg(II) ions were investigated. The copolymer-metal ion complexes were obtained in aqueous phase by using the Liquid Phase Polymer-Based Retention (LPR) technique in conjunction with membrane filtration. The water-soluble P(MG) and P(MG-co-AA) are shown to be useful for the retention of different metal ions and their separation from elements not bound to the polymeric reagent. The thermal stability of the copolymer-metal ion complexes under nitrogen atmosphere at 20–500°C was also investigated. The complexes with different transition were characterized with FT-IR and thermogravimetry (TGA). From the TGA data the thermal decomposition temperature (TDT) and kinetic parameters such as activation energy (Ea) and reaction order (n) were determined. Received: 21 April 1998/Revised version: 16 July 1998/Accepted: 22 July 1998     

Free radical copolymerization of functional water-soluble poly(N-maleoylglycine-co-crotonic acid): polymer metal ion retention capacity, electrochemical, and thermal behavior

In this study, the water-soluble polymers of N-maleoyl glycine (MG) with crotonic acid (CA) were copolymerized by free radical polymerization to obtain hydrophilic polymers, in order to study the effect of the functional groups in the copolymers on the metal ion retention capacity, electrochemical and thermal behavior, since that important requirements for their use in technological applications are: high solubility in water, chemical stability, a high affinity for one or more metal ions, and selectivity for the metal ion of interest. The metal complexation properties of poly(MG-co-CA) for the metal ions were investigated at pH 3, 5, and 7 in aqueous solution. The metal ion investigated were: Cu(II), Co(II), Cr(III), Ni(II), Cd(II), Zn(II), and Fe(III). The polymeric systems showed high metal ion retention for Zn (II) and Fe(III) at different pH. At different pHs, the MRC of the poly(MG-co-CA) for Fe(III) ions varied from 122.1 to 146.2 mg/g and from 120.5 to 133.5 mg/g, (samples 1 and 2 at pH 3 and 7, respectively). The MRC had the highest retention values for both copolymer systems at pH 7. The copolymers presented higher thermal decomposition temperature (TDT) in comparison with copolymer–metal complexes at pH 3 and 5. The cyclic voltammetry (CV) for poly(MG-co-CA) (20 mM) was compared with the CV of the [poly(MG-co-CA)–Fe(III)] copolymer complex. Moreover, [poly(MG-co-CA)–Fe(III)] showed a redox wave difference between +0.25 and +0.50 V possibly due to the presence of metal complexed with the polymer. The electrochemical characterization of the copolymer poly(MG-co-AC) shown the reduction of carboxylic acid groups of the N-maleoylglycine and crotonic acid moiety to hydroxyl group. The results support the assumption that the copolymer presents convenient electroactivity.     

Resins containing amino and carboxylic acid groups. Synthesis,characterization, and metal ion retention properties

The crosslinked poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide], P(MAPDSA), and poly[3‐(methacryloylamino)propyl]dimethyl(3‐sulfopropyl)ammonium hydroxide‐co‐acrylic acid], P(MAPDSA‐co‐AA), were synthesized by radical polymerization. The resins were completely insoluble in water. Due to the lower metal ion retention of P(MAPDSA), the metal ions investigated under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) ions by batch and column equilibrium procedures were carried out only for P(MAPDA‐co‐AA), particularly for Hg(II). The resin–Hg(II) ion equilibrium was achieved before 15 min. The resin showed a maximum retention capacity value for Hg(II) at pH 2 of 1.89 meq/g. The resin showed a high selectivity to Hg(II) ions. The recovery of the resin was investigated at 25°C with different concentrations of HNO₃ and HClO₄. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 525–530, 2005     

Preparation and adsorption properties of the chelating resins containing carboxylic,sulfonic, and imidazole groups

The crosslinked poly(1‐vinylimidazole‐co‐acrylic acid), P(VIm‐co‐AA), and poly(1‐vinylimidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid) P(VIm‐co‐APSA) were synthesized by radical polymerization and tested as adsorbents under competitive and noncompetitive conditions for Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), and Cr(III) by batch equilibrium procedure. The resin–metal ion equilibrium was achieved before 1 h. The resin P(VIm‐co‐AA) showed a maximum retention capacity (MRC) value for Pb(II) at pH 3 and Hg(II) at pH 1 of 1.1 and 1.2 mEq/g, respectively, and the resin P(VIm‐co‐AA) showed at pH 3 the following MRC values: Hg(II) (1.5 mEq/g), Cd(II) (1.9 mEq/g), Zn(II) (2.7 mEq/g), and Cr(III) (2.8 mEq/g). The recovery of the resin was investigated at 25°C with 1 M and 4 M HNO₃ and 1 M and 4 M HClO₄. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2852–2856, 2003     

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

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), ¹H and ¹³C 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 500°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Heavy metal ions removal through poly(acrylamide-co-methacrylic acid) resin

The resin poly(acrylamide-co-methacrylic acid) P(AAm-co-MA) by radical polymerization was synthesized and its metal ion binding was studied using the batch and column equilibrium procedures for: Cd(II), Zn(II), Pb(II), Hg(II), Al(III), and Cr(III). Experiments were carried out at different pH, metal ion concentration, temperature, and contact time. The resin’s retention behavior was influenced by the pH. The highest retention 91% (0.248 mmol/g, 6.7 mg/g) was achieved at pH 5 for Al(III), and 87% (0.265 mmol/g, 54.9 mg/g) for Pb(II). For Hg(II), the yield was 85% (0.318 mmol/g, 63.7 mg/g) at pH 2. The metal-ion retention properties were dependent on the polymer/metal ion ratio. Under competitive conditions of Pb(II), Hg(II), and Al(III), the resin showed a higher retention of Hg(II), allowing the selective separation of this metal.     

Metal‐ion‐retention properties of the poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine) resin

The water‐insoluble resin poly(2‐acrylamido‐2‐methyl‐1‐propanosulfonic acid‐co‐4‐vinyl pyridine), through a radical polymerization solution, was synthesized with ammonium persulfate as an initiator and N,N‐methylene bisacrylamide as a crosslinking reagent. The metal‐ion‐retention properties were studied by batch and column equilibrium procedures for the following metal ions: Hg(II), Cu(II), Cd(II), Zn(II), Pb(II), and Cr(III). These properties were investigated under competitive and noncompetitive conditions. The effects of the pH, maximum retention capacity, and regeneration capacity were studied. The resin showed a high retention ability for Hg(II) ions at pH 2.0. The retention of Hg(II) ions from a mixture of ions was greater than 90%. The resin showed a high selectivity for Hg(II) with respect to other metal ions. The Hg(II)‐loaded resin was able to be recovered with 4M HClO₄. The retention capacity was kept after four cycles of adsorption and desorption. The retention properties for Hg(II) were very similar with the batch and column methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3556–3562, 2003     

Application of a synthetic water-soluble poly(N-maleyl glycine-co-acrylamide) as polychelatogen for inorganic ions in aqueous solutions

Summary The water-soluble poly(N-maleyl glycine-co-acrylamide) (P(MG-co-Am)) reagent with strong complexing properties for the inorganic ions Cr(III), Co(II), Zn(II), Ni(II), Cu(II), Cd(II), Pb(II), Hg(II), As(V), and Se(IV) was investigated in aqueous phase in conjunction with membrane filtration using the Liquid-phase Polymer-based Retention (LPR) technique. The P(MG-co-Am) was shown to be useful for retention of different inorganic ions and their separation from elements not bound to the polymeric reagent. The inorganic ion interaction with the hydrophilic polymer was determined as a function of pH and filtration factor. At higher pH, the copolymer can be applied to the separation and preconcentration of most of the inorganic ions. Viscosimetric measurements of the copolymers were performed in the presence of metal ions at different pH values. Received: 8 July 1998/Revised version: 23 October 1998/Accepted: 27 October 1998     

Poly(4-sodium styrene sulfonate-co-4-acryloylmorpholine). Synthesis,Characterization, and Metal Ion Retention Properties

Abstract

A novel resin poly(sodium 4-styrene sulfonate-co-4-acryloyl morpholine) was synthesized through a radical solution polymerization in solution and studied as an adsorbent under uncompetitive and competitive conditions by batch and column equilibrium procedures for the following divalent metal ions Cd(II), Zn(II), Pb(II), and Hg(II), and trivalent Cr(III). For all metal ions, the adsorption was strongly influenced by the pH. The maximum retention capacity, 3.29 mmol of metal ion/g, was obtained for Zn(II) at pH 5 by batch equilibrium procedure. For both the batch and column procedures, the retention behavior was similar for Cd(II), Cr(III), Zn(II), and Pb(II).     

Water‐insoluble polymers containing amine,sulfonic acid,and carboxylic acid groups: Synthesis,characterization, and metal‐ion‐retention properties

Crosslinked poly(acryloylmorpholine) and its copolymers poly(acryloyl morpholine‐co‐acrylic acid) and poly(acryloylmorpholine‐co‐2‐acrylamide‐2‐methyl‐1‐propane sulfonic acid) were synthesized by radical polymerization. The resins were completely insoluble in water and were characterized with Fourier transform infrared spectroscopy and thermal analysis. The metal ions Ag(I), Cu(II), Cd(II), Hg(II), Zn(II), Pb(II), Al(III), and Cr(III) were investigated under competitive and noncompetitive conditions by a batch equilibrium procedure. The resin‐metal‐ion equilibrium was achieved before 5 min. The recovery of the resin was investigated at 20°C with different concentrations of HNO₃ and HClO₄. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3266–3274, 2006     

Synthesis,characterization, and metal complexation of poly(N‐phenylmaleimide‐co‐acrylic acid) and poly(N‐phenylmaleimide‐co‐acrylamide) as polychelatogens in aqueous solution

We carried out the free‐radical copolymerization of N‐phenylmaleimide with acrylic acid and acrylamide with an equimolar feed monomer ratio. We carried out the synthesis of the copolymers in dioxane at 70°C with benzoyl peroxide as the initiator and a total monomer concentration of 2.5M. The copolymer compositions were obtained by elemental analysis and ¹H‐NMR spectroscopy. The hydrophilic polymers were characterized by elemental analysis, Fourier transform infrared spectroscopy, ¹H‐NMR spectroscopy, and thermal analysis. Additionally, viscosimetric measurements of the copolymers were performed. Hydrophilic poly(N‐phenylmaleimide‐co‐acrylic acid) and poly(N‐phenylmaleimide‐co‐acrylamide) were used for the separation of a series of metal ions in the aqueous phase with the liquid‐phase polymer‐based retention method in the heterogeneous phase. The method is based on the retention of inorganic ions by the polymer in conjunction with membrane filtration and subsequent separation of low‐molecular‐mass species from the formed polymer/metal‐ion complex. The polymer could bind several metal ions, such as Cr(III), Co (II), Zn(II), Ni(II), Cu(II), Cd(II), and Fe(III) inorganic ions, in aqueous solution at pH values of 3, 5, and 7. The interaction of the inorganic ions with the hydrophilic polymer was determined as a function of pH and a filtration factor. Hydrophilic polymeric reagents with strong metal‐complexing properties were synthesized and used to separate those complexed from noncomplexed ions in the heterogeneous phase. The polymers exhibited a high retention capability at pH values of 5 and 7. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Synthesis,characterization and polychelatogenic properties of poly[(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid)‐co‐(methacrylic acid)]

Poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid), poly(methacrylic acid), and five copolymers of poly[(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)‐co‐(methacrylic acid)] were synthesized by radical polymerization and obtained in yields >97%. The polymers were characterized by FT‐IR, [¹H]NMR, and [¹³C]NMR and studied by means of the Liquid‐phase Polymer‐based Retention (LPR) technique. The metal ion retention ability of the copolymers for Cu(II), Cd(II), Co(II), Hg(II), Ni(II), Zn(II), Cr(III) and Ag(I) was investigated at different pH values because of their environmental and analytical interest. The retention profiles of the copolymers were compared with those of the corresponding homopolymers and retention of metal ions was found to increase with increasing pH. © 2001 Society of Chemical Industry     

Metal ion sorption properties of water-insoluble resins based on sodium styrene sulfonate and different comonomers

A set of water-insoluble resins based on sodium styrene sulfonate and different comonomers were synthesized. The resins poly(mono-2-(methacryloyloxy)ethyl succinate-co-sodium 4-styrene sulfonate) P(MOES-co-SSNa), poly(2-acrylamido glycolic acid-co-sodium 4-styrene sulfonate) P(AGA-co-SSNa), poly(acrylamide-co-sodium 4-styrene sulfonate) P(AAm-co-SSNa), and poly(2-(dimethylamine)ethyl acrylate-co-sodium 4-styrene sulfonate) P(DMAEA-co-SSNa) were synthesized by solution radical polymerization. The metal ion retention properties were studied by batch procedure for Cd(II), Zn(II), Pb(II), and Hg(II). Resins performance was compared with a poly(sodium 4-styrene sulfonate) (PSSNa) resin in order to evaluate the effect of comonomer on sorption properties. The effect of pH, time, temperature, and maximum retention capacity were studied. In addition, sorption experiments were carried out under competitive ion conditions to study the selectivity of resins. The resins P(AAm-co-SSNa) and P(AGA-co-SSNa), showed the most important differences compared with PSSNa resin, the former present higher sorption and the latter presented selectivity for Hg(II) at pH 2.     

Polyelectrolyte‐assisted removal of metal ions with ultrafiltration

The water‐soluble polymers poly(styrene sulfonic acid‐co‐maleic acid) and poly(acrylic acid‐co‐maleic acid) were investigated with respect to their metal‐ion‐binding ability with ultrafiltration. The studied metal ions included Ag(I), Cu(II), Ni(II), Co(II), Ca(II), Mg(II), Pb(II), Cd(II), Zn(II), Al(III), and Cr(III) ions. The retention properties of the polyelectrolytes for the metal ions depended strongly on the ligand type. As for the carboxylate ligands, with increasing concentration and pH, the metal‐binding affinity increased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1091–1099, 2005     

Synthesis,characterization, and catalytic activity of 4 mol % N,N′‐methylene bisacrylamide crosslinked poly(acrylic acid)–metal complexes

The metal‐ion complexation behavior and catalytic activity of 4 mol % N,N′‐methylene bisacrylamide crosslinked poly(acrylic acid) were investigated. The polymeric ligand was prepared by solution polymerization. The metal‐ion complexation was studied with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) ions. The metal uptake followed the order: Cu(II) > Cr(III) > Mn(II) > Co(II) > Fe(III) > Zn(II) > Ni(II). The polymeric ligand and the metal complexes were characterized by various spectral methods. The catalytic activity of the metal complexes were investigated toward the hydrolysis of p‐nitrophenyl acetate (NPA). The Co(II) complexes exhibited high catalytic activity. The kinetics of catalysis was first order. The hydrolysis was controlled by pH, time, amount of catalyst, and temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 272–279, 2004     

Resin I: Synthesis,characterization, and ion‐exchange properties of terpolymer resins derived from 2,4‐dihydroxypropiophenone,biuret, and formaldehyde

Terpolymers (2,4‐DHPBF) were synthesized by the condensation of 2,4‐dihydro‐xypropiophenone, biuret, and formaldehyde in the presence of acid catalyst with varying the molar ratio of reacting monomers. Terpolymer composition has been determined on the basis of their elemental analysis and their number–average molecular weight of these resin were determined by conductometric titration in nonaqueous medium. The viscosity measurements were carried out in N,N‐dimethyl formamide which indicate normal behavior. IR spectra were studied to elucidate the structure. The terpolymer resin has been further characterized by UV–visible and ¹H‐NMR spectra. The newly synthesized terpolymers proved to be selective chelating ion‐exchange terpolymers for certain metals. The chelating ion‐exchange properties of this terpolymer was studied for Fe (III), Cu (II), Hg (II), Cd (II), Co (II), Zn (II), Ni (II), and Pb (II) ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the terpolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The terpolymer showed a higher selectivity for Fe (III), Hg (II), Cd (II), and Pb (II) ions than for Cu (II), Co (II), Zn (II), and Ni (II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008