Preparation of Chelating Resins Containing a Pair of Neighboring Carboxylic Acid Groups and the Adsorption Characteristics for Heavy Metal Ions

Abstract

For the functional enhancement of chelating resins containing carboxylic acids, copolymer beads were prepared by suspension polymerization of styrene (St), methyl methacrylate (MMA), and divinylbenzene (DVB) in the presence of toluene as diluent. The phenyl rings of the beads were directly chloromethylated, and the carboxylic ester groups of the beads were converted into hydroxymethyl groups by reduction followed by chlorination to give chloromethyl groups, respectively. The chelating resins containing a pair of neighboring carboxylic acid groups (NCAGs) were obtained by the alkylation of chloromethyl groups in copolymer beads with diethyl malonate in the presence of sodium hydride followed by hydrolysis using aqueous alkali solution. Accordingly, the structural effects of the resins on the adsorption of heavy metal ions were investigated. Poly(St‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb²⁺, Cd²⁺, and Cu²⁺, whereas poly(MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Cu²⁺, Cd²⁺, and Co²⁺. On the other hand, poly(St‐co‐MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb²⁺, Cd²⁺, Hg²⁺, Co²⁺, and Cu²⁺: a synergistic effect on the adsorption of heavy metal ions like Pb²⁺, Cd²⁺, Hg²⁺, and Co²⁺ was observed. The adsorption ability of poly(St‐co‐MMA‐co‐DVB)‐based chelating resin among three kinds of chelating resins was relatively good.     

Ligating behavior and metal uptake of N‐sulphonylpolyamine chelating resins anchored on polystyrene‐divinylbenzene beads

Amberlite XAD‐2 has been functionalized by coupling through –SO₂‐with ethylenediamine, propylenediamine, and diethylenetriamine to give the corresponding polyamine chelating resins I–III. The solid metallopolymer complexes of the synthesized chelating resins with Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ were synthesized. The polyamine derivatives and their metal complexes were characterized by elemental analysis, spectral (IR, UV/V, and ESR), and magnetic studies. The batch equilibrium method was utilized for using the chelating polyamines for the removal of Cu⁺², Zn⁺², Cd⁺², and Pb⁺² ions from aqueous solutions at different pH values and different shaking times at room temperature. The selective extraction of Cu⁺² from a mixture of the four metal ions and the metal capacities of the chelating resins were evaluated using atomic absorption spectroscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1839–1846, 2005     

Synthesis and adsorption properties,toward some heavy metal ions,of a new polystyrene‐based terpyridine polymer

A novel polymeric ligand having 2,2′:6′,2″‐terpyridine as pendant group was prepared through a Williamson type etherification approach for the reaction between 4′‐hydroxy‐2,2′: 6′,2″‐terpyridine and the commercially available 4‐chloromethyl polystyrene. The chelating properties of the new polymer toward the divalent metal ions (Cu²⁺, Zn²⁺, Ni²⁺, and Pb²⁺) in aqueous solutions was studied by a batch equilibration technique as a function of contact time, pH, mass of resin, and concentration of metal ions. The amount of metal‐ion uptake of the polymer was determined by using atomic absorption spectrometry. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Pb²⁺ and that the metal‐ion uptake follows the order: Pb²⁺ > Cu²⁺ > Zn²⁺ > Ni²⁺. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Chelation ion‐exchange study of copolymer resin derived from 8‐hydroxyquinoline 5‐sulphonic acid,oxamide, and formaldehyde

Copolymers (8‐HQ5‐SAOF) were synthesized by the condensation of 8‐hydroxyquinoline 5‐sulphonic acid (8‐HQ5‐SA) and oxamide (O) with formaldehyde (F) in the presence of acid catalyst. Four different copolymers were synthesized by using varied molar proportion of the reacting monomers. Copolymer resin composition has been determined on the basis of their elemental analysis and average molecular weights of these resins were determined by conductometric titration in nonaqueous medium. Viscometric measurement in dimethyl sulphoxide (DMSO) has been carried out with a view to ascertain the characteristic functions and constants. Electronic spectra, FTIR, and proton nuclear magnetic resonance spectra were studied to elucidate the structures. The newly synthesized copolymer proved to be a selective chelating ion‐exchange copolymer for certain metals. The chelating ion‐exchange properties of this synthesized copolymer was studied for different metal ions such as Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺, and Pb²⁺. A batch equilibrium method was used in the study of the selectivity of metal ion uptake involving the measurements of the distribution of a given metal ion between the copolymer sample and a solution containing the metal ion only for representative copolymer 8‐HQ5‐SAOF‐I due to economy of space. The study was carried out over a wide pH range, shaking time, and in media of various ionic strengths. The copolymer showed a higher selectivity for Fe³⁺, Cu²⁺, and Ni²⁺ ions than for Co²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Chelation ion‐exchange properties of copolymer resin derived from 4‐hydroxyacetophenone,oxamide, and formaldehyde

A copolymer (4‐HAOF) prepared by condensation of 4‐hydroxyacetophenone and oxamide with formaldehyde in the presence of an acid catalyst proved to be a selective chelating ion‐exchange copolymer for certain metals. Chelating ion‐exchange properties of this copolymer were studied for Fe³⁺, Cu²⁺, Ni²⁺, Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺, and Hg²⁺ ions. A batch equilibrium method was employed in the study of the selectivity of metal‐ion uptake involving the measurements of the distribution of a given metal ion between the copolymer 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 copolymer showed a higher selectivity for Fe³⁺ ions than for Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺, Cu²⁺, Ni²⁺, and Hg²⁺ ions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 787–790, 2003     

Separation of metal ions by the influence of a cation‐exchange terpolymer involving 2‐amino‐6‐nitrobenzothiazole–ethylenediamine–formaldehyde

A novel terpolymer involving 2‐amino‐6‐nitrobenzothiazole and ethylenediamine with formaldehyde was synthesized by a polycondensation technique using glacial acetic acid as a reaction medium. The resulting chelating terpolymer resin was characterized using elemental analysis, physicochemical parameters, and UV‐visible, Fourier transform infrared, ¹H NMR and ¹³C NMR spectral studies. Average molecular weights of the terpolymer were determined using gel permeation chromatography. The surface morphology and the nature of the terpolymer were investigated using scanning electron microscopy and X‐ray diffraction. The chelation ion‐exchange property of the terpolymer was determined against some common metal ions such as Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Pb²⁺ using the batch equilibrium method. Effects of parameters such as the pH, contact time and various electrolyte concentrations were studied. The reusability of the terpolymer was checked in terms of its effective repeated usage. The results of the Langmuir and Freundlich adsorption isotherm models were best fitted with each other and the reaction kinetics followed pseudo second‐order kinetics. The terpolymer showed good results against Fe³⁺, Cu²⁺ and Ni²⁺ ions compared to those against the other metal ions. © 2014 Society of Chemical Industry     

Synthesis and adsorption properties of macroporous cross‐linked polystyrene that contains an immobilizing 2,5‐dimercapto‐1,3,4‐thiodiazole with tetraethylene glycol spacers

A novel chelating resin macroporous cross‐linked polystyrene immobilizing 2,5‐dimercapto‐1,3,4‐thiodiazole via a hydrophilic tetraethylene glycol spacer (PS‐TEG‐BMT) is synthesized and the structure is characterized by means of Fourier transform infrared spectroscopy (FTIR), energy dispersive X‐ray microanalysis (EDX), and elementary analysis. Its adsorption capacity for several metal ions such as Hg²⁺, Ag⁺, Ni²⁺, Pb²⁺, Cd²⁺, Fe³⁺, Bi³⁺, Zn²⁺, and Cu²⁺ are investigated. The initial experimental result shows that this resin has higher adsorption selectivity for Hg²⁺ and Ni²⁺ than for the other metal ions and the introduction of hydrophilic TEG spacer is beneficial to increase adsorption capacities. The result also shows that the Langmuir model is better than the Freundlich model to describe the isothermal process of PS‐TEG‐BME resin for Hg²⁺. Five adsorption‐desorption cycles demonstrate that this resin are suitable for reuse without considerable change in adsorption capacity. POLYM. ENG. SCI., 45:1515–1521, 2005. © 2005 Society of Plastics Engineers     

Copolymer resin. VII. 8‐hydroxyquinoline‐5‐sulfonic acid–thiourea–formaldehyde copolymer resins and their ion‐exchange properties

8‐Hydroxyquinoline‐5‐sulfonic acid–thiourea–formaldehyde copolymer resins were synthesized through the condensation of 8‐hydroxyquinoline‐5‐sulfonic acid and thiourea with formaldehyde in the presence of hydrochloric acid as a catalyst and with various molar ratios of the reacting monomers. The resulting copolymers were characterized with UV‐visible, IR and 1H‐NMR spectral data, employed to determine the reactivity of monomers. The average molecular weights of these resins were determined with vapor pressure osmometry and conductometric titration in a nonaqueous medium. The chelation ion‐exchange properties were also studied with the batch equilibrium method. The resins were proved to be selective chelating ion‐exchange copolymers for certain metals. The chelation ion‐exchange properties of these copolymers were studied for Cu²⁺, Ni²⁺, Co²⁺, Pb²⁺, and Fe³⁺ ions. The study was carried out over a wide pH range and in media of various ionic strengths. The copolymers showed a higher selectivity for Fe³⁺ ions than for Cu²⁺, Ni²⁺, Co²⁺, and Pb²⁺ ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Thiourea modified hyper‐crosslinked polystyrene resin for heavy metal ions removal from aqueous solutions

A hyper‐crosslinked resin chemically modified with thiourea (TM‐HPS) was synthesized, characterized, and evaluated for the removal of heavy metal ions (Pb²⁺, Cd²⁺, and Cu²⁺) from aqueous solutions. The structural characterization results showed that a few thiourea groups were grafted on the surface of the resin with a big BET surface area and a large number of narrow micropores. Various experimental conditions such as pH, contact time, temperature, and initial metal concentration of the three heavy metal ions onto TM‐HPS were investigated systematically. The results indicated that the prepared resin was effective for the removal of the heavy metal ions from aqueous solutions. The isotherm data could be better fitted by Langmuir model, yielding maximum adsorption capacities of 689.65, 432.90, and 290.69 mg/g for Pd²⁺, Cd²⁺, and Cu²⁺, respectively. And the adsorption kinetics of the three metal ions followed the pseudo‐second‐order equation. FTIR and XPS analysis of TM‐HPS before and after adsorption further revealed that the adsorption mechanism could be a synergistic effect between functional groups and metal ions and electrostatic attraction, which may provide a new insight into the design of highly effective adsorbents and their potential technological applications for the removal of heavy metal ions from aqueous solutions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45568.     

Sorption properties of the iminodiacetate ion exchange resin,amberlite IRC‐718, toward divalent metal ions

The sorption properties of the commercially available cationic exchange resin, Amberlite IRC‐718, that has the iminodiacetic acid functionality, toward the divalent metal‐ions, Fe²⁺, Cu²⁺, Zn²⁺, and Ni²⁺ were investigated by a batch equilibration technique at 25°C as a function of contact time, metal ion concentration, mass of resin used, and pH. Results of the study revealed that the resin exhibited higher capacities and a more pronounced adsorption toward Fe²⁺ and that the metal‐ion uptake follows the order: Fe²⁺ > Cu²⁺> Zn²⁺ >Ni²⁺. The adsorption and binding capacity of the resin toward the various metal ions investigated are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Sorption behavior of ion-exchange terpolymer resin with environmental impact: synthesis,characterization and isotherm models

A novel terpolymer acts as an effective chelating ion exchanger which was synthesized using 2-amino-6-nitro-benzothiazole and semicarbazide with formaldehyde (BSF) by solution condensation technique. Its ion exchange properties was determined against certain metal ions viz. Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Pb²⁺ using batch equilibrium technique with different electrolyte concentrations, pH ranges and time intervals. The results of batch studies revealed that the separation of the selected metal ions from the aqueous solution by the terpolymer is found to be excellent compared to the available commercial resins and earlier reported resins. The order of metal ion uptake at higher concentrations by the BSF terpolymer at lower pH is Cu²⁺ > Ni²⁺ > Fe³⁺ and at lower concentration at higher pH is Zn²⁺ > Co²⁺ > Pb²⁺. The reusability of the resin was also reported for its effective ion-exchange behaviour for several cycles. The adsorption isotherm model was evaluated and the results are in good agreement with each other. The order of kinetics was also determined and the resin follows pseudo-second-order kinetics. Moreover, the physico-chemical analysis gives strong evidence for the effective metal ion removal compared with the earlier reported and commercial resins. Earlier, the structure and the properties of the synthesized novel chelating resin were clearly elucidated by elemental, FTIR, UV–Vis, ¹H & ¹³C NMR spectra, GPC, SEM and XRD.     

Adsorption properties of novel chelating resins containing 2‐amino‐5‐methylthio‐1,3,4‐thiadizole and hydrophilic spacer arms for Hg2+ and Ag+

The adsorption properties, including the adsorption kinetics, adsorption isotherms, and adsorption selectivity, of newly formed chelating resins that contained a heterocyclic functional group and a hydrophilic spacer arm of poly(ethylene glycol) [polystyrene–diethylene glycol–2‐amino‐5‐methylthio‐1,3,4‐thiadizole (PS–DEG–AMTZ) and polystyrene–triethylene glycol–2‐amino‐5‐methylthio‐1,3,4‐thiadizole (PS–TEG–AMTZ)] were studied in detail. The results show that the adsorption kinetics of PS–DEG–AMTZ and PS–TEG–AMTZ for Hg²⁺ and Ag⁺ could be described by a pseudo‐second‐order rate equation. The introduction of a spacer arm between the polymeric matrix and functional group was beneficial for increasing the adsorption rates. The apparent activation energies of the resins for Hg²⁺ and Ag⁺ were within 20.89–32.32 kJ/mol. The Langmuir model could describe the isothermal process of Hg²⁺ and Ag⁺. The competitive adsorption of the resins for Hg²⁺ and Ag⁺ in binary mixture systems was also investigated. The results show that Hg²⁺ and Ag⁺ were adsorbed before the other metal ions, such as Cu²⁺, Zn²⁺, Fe³⁺, Cd²⁺, and Pb²⁺, under competitive conditions. Five adsorption–desorption cycles were conducted for the reuse of the resins. The results indicate that these two resins were suitable for reuse without considerable changes in the adsorption capacity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation of gel resins and removal of copper and lead from water

A series of gel resins were prepared by polymerizing glycidyl methacrylate (GMA) and 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) and functionalizing with ammonia (NH₃) and tetraethylenepentamine (TEPA). The aminated gel resins were then used as an adsorbent for the removal of heavy metal ions (Cu²⁺ and Pb²⁺). These gel resins containing amino groups and chelating amino groups had excellent adsorptive properties for Cu²⁺ and Pb²⁺. The adsorption process reached equilibrium in 40 min, and the adsorption capacities of Cu²⁺ and Pb²⁺ were 75.0 mg g^?1 and 266.6 mg g^?1 for the NH₃‐aminated gel resins and 57.5 mg g^?1 and 330.6 mg g^?1 for the TEPA‐aminated gel resins, respectively. After five adsorption–desorption processes, the adsorption capacities only decreased slightly. Thus, these aminated gel resins can be used as effective adsorbents for aqueous heavy metal ions (Cu²⁺ and Pb²⁺). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44466.     

Synthesis and characterization of a new guar gum 4‐hydroxybenzoic acid resin and its use for the separation of heavy metal ions in industrial effluents

Hydroxybenzoic acid group has been incorporated onto guar gum by modified Porath's method of functionalization of polysaccharides. The newly synthesized guar gum 4‐hydroxybenzoic acid (GHBA) resin was characterized by Fourier‐transform infrared spectroscopy, elemental analysis, ion‐exchange capacity, column reusability, and physicochemical properties. The distribution coefficient (K_d) values and effect of pH on chelation of these metal ions using batch method were studied. The separations of mixture of Fe²⁺, Zn²⁺, Cu²⁺, Cd²⁺, and Pb²⁺ metal ions on GHBA resin on the basis of their distribution coefficient at various pH were also achieved using column chromatography. The effect of experimental parameters such as pH, treatment time, agitation speed, temperature, adsorbent dose, initial metal ion concentration, and flow rate on the removal of metal ions has been also studied. GHBA resin is effective adsorbents for the removal of different toxic metal ions from aqueous solutions and follows the order: Fe²⁺ > Zn²⁺ > Cu²⁺ > Cd²⁺ > Pb²⁺. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers     

Chelating polymer bearing triazolylazophenol moiety as the functional group

The chelating polymer-bearing triazolylazophenol moiety as the functional group was synthesized, its metal adsorption properties for 6 divalent heavy metal ions; Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ were investigated. The capacity of the polymer for Cu²⁺ achieved 8.7 mEq/g in pH 5.3 solution. The polymer showed remarkable color changes from orange to red violet or blue violet with its chelations to the heavy metal ions. The metal adsorption rates of the polymer were rapid in performing complete capacity saturation of heavy metal ions in about 30 min. The capacities varied little the presence of alkali or alkaline earth metal ions in solutions. The perfect elimination of metals from the polymer–M²⁺ chelates were performed with mineral acid solutions. The metal ions; Cu²⁺ and Ni²⁺ in plating-process solutions were effectively removed by the chelating polymer, and the polymer can be practically used for the removal of these ions from waste water.     

Highly porous,water-swellable,and reusable chelating polymeric gels for heavy metal ion removal from aqueous waste

Sequestration and removal of heavy metal ions from aqueous solutions pose multiple challenges. Ease of synthesis, high adsorption capacity and ease of regeneration are important considerations in the design of polymeric adsorbent materials developed for this purpose. To meet this objective, a new approach was used to design and synthesize a highly porous polystyrene-based resin (IDASR15) bearing iminodiacetate functional groups in every repeat unit by free radical polymerization with N, N'-methylenebisacrylamide as crosslinker followed by base hydrolysis. The physiochemical chemical properties of the resin were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, equilibrium swelling value (ESV) and thermogravimetric analysis. Metal uptake capacity of IDASR15 towards low concentrations of various toxic heavy metal ions such as Cu²⁺, Cd²⁺, Mn²⁺, Zn²⁺, Pb²⁺, Ni²⁺, Co²⁺, Co³⁺, Cr³⁺, Fe²⁺, Fe³⁺, and Al³⁺ were investigated from their aqueous solution by batch method and found to be 0.943–2.802 mmol/g. The maximum capacity was 2.802 mmol/g obtained for Cu²⁺ ion at pH 5. The potential for regeneration and reuse has been demonstrated with Cu²⁺ ion by batch and column methods. The reported results suggest that IDASR15 is a highly efficient and porous complexing agent for commonly found toxic metal ions in aqueous streams with a high ESV of 68.55 g of water/1.0 g of IDASR15. It could also be reused ~99.5% of adsorption efficiency which is very promising and holds significant potential for waste-water treatment applications.     

Preparation and adsorption selectivity for Hg(II) and Ag(I) of chelating resin immobilizing benzothiazolyl group on crosslinked polystyrene via hydrophilic sulfur‐containing PEG spacer

A new chelating resin incorporating 2‐mercaptobenzothiazole (MBZ) into macroporous chloromethylated polystyrene via hydrophilic spacer of polyethylene glycol containing sulfur was synthesized. The resin was characterized by elementary analysis and infrared spectra. The adsorption capacity of the resin for Ag⁺, Hg²⁺, Cu²⁺, Zn²⁺, and Pb²⁺ as a function of pH was determined. The effects of interference ions, such as Na⁺, Mg²⁺, Ca²⁺, Ba²⁺, Cu²⁺, Zn²⁺, and Pb²⁺, on percent recovery were also investigated. The results showed that the resin could effectively remove Hg²⁺ and Ag⁺ from solutions containing a large excess of Na⁺, Mg²⁺, Ca²⁺, Ba²⁺, Cu²⁺, Zn²⁺, and Pb²⁺. In column operation, it was observed that Hg²⁺ and Ag⁺ in trace quantities were effectively removed from binary metal ions. The percent recovery of the resin for Hg²⁺ and Ag⁺ was >98.6% and >97.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5034–5038, 2006     

Synthesis of a polyacrylamide chelating resin and applications in metal ion extractions

A series of differently crosslinked polyacrylamide chelating resins were prepared, using N,N′-methylene-bis-acrylamide as the crosslinking agent. The crosslinked resins were functionalized by the reaction with ethylene diamine to get amino group capacities varying from 4.2 to 1.1 mequiv/g. The maximum adsorption capacities of the lightly crosslinked resin for Fe³⁺, Fe²⁺, Ni²⁺, and Cu²⁺ are 3.62, 4.22, 1.48, and 1.67 mequiv/g, respectively. The adsorbed metal ions can be quantitatively desorbed. The adsorption rate and the influence of pH on the adsorption of metal ions were examined. The resins can be used for the separation between different metal ions as well as the ions in different valence states (e.g., Fe³⁺ and Fe²⁺). The resin is amenable for continuous process and can be regenerated several times.     

Synthesis,characterization, and metal adsorption properties of tannin–phenol–formaldehyde resins produced using tannin from dried fruit of Terminalia chebula (Aralu)

In this study, tannin extracted from Terminalia chebula (Aralu) was used to produce tannin–phenol–formaldehyde resins. They were produced to obtain resins with different tannin to phenol ratio in an attempt to optimize the ion exchange capacities of resins produced. The resins made were sulfonated to improve their properties further. Bivalent cations, such as Zn²⁺, Pb²⁺, Ca²⁺, Mg²⁺, and Cu²⁺, were used to estimate the adsorption properties of both unsulfonated and sulfonated resins. The glass transitions of representative resins were estimated using differential scanning calorimeter thermograms. Fourier transform infrared spectroscopic analysis was used to gauge changes on resins by sulfonation and adsorption of cations. The glass transition values of unsulfonated, sulfonated, and metal‐adsorbed sulfonated resins showed a similar increasing trend with the increase of phenol content in the resin. The glass transition temperature values reach a plateau beyond the tannin/phenol ratio of 1 : 0.5, indicating the formation of large molar masses facilitating entanglements beyond that ratio. The phenol ratio of 1 : 0.5 has shown the highest adsorption capacity for all the metal ions used. The highest adsorption capacity was shown for sulfonated tannin–phenol–formaldehyde resin with the tannin/phenol ratio of 1 : 0.5 for Pb²⁺, which is 0.610 meq/g. The adsorption equilibrium data obtained using the column technique were found fitting Freundlich isotherm. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and adsorption properties of poly(N‐vinylformamide/acrylonitrile) chelating fiber for heavy metal ions

In this article we report a new chelating fiber that was prepared from a hydrolyzate of poly(N‐vinylformamide/acrylonitrile) by a wet‐spinning method. This fiber contains chelating groups, such as amidine groups, amino groups, cyano groups, and amide groups, with high densities. We examined the chelating abilities for several metal ions with this fiber, and present the morphological merit of the fibrous product compared with the globular resin. Based on the research results, it is shown that the fiber has higher binding capacities and better adsorption properties for heavy metal ions than the resin. The pH value of the metal ion solution shows strong influences on the adsorption of the metal ions. The maximum adsorption capacities of the fiber for Cu²⁺, Cr³⁺, Co²⁺, Ni²⁺, and Mn²⁺ are 112.23, 88.11, 141.04, 108.06, and 73.51 mg/g, respectively. In mixed metal ions solution, the fiber adsorbs Cr³⁺, Cu²⁺ and Co²⁺ efficiently. The adsorbed metal ions can be quantitatively eluted by hydrochloric acid. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1378–1386, 2002