Sulfated katira gum‐graft‐poly(N‐vinyl imidazole): A useful scavenger of mercury(II) ions

Katira gum-graft-poly(N-vinyl imidazole) was synthesized in a water medium with potassium perdisulfate as the free-radical initiator at 70 ± 1 °C. The graft copolymer was sulfated by chlorosulfonic acid in the presence of pyridine and formamide. Various characterization techniques, including Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy, were used to characterize both the unsulfated and sulfated graft copolymers. The sulfated graft copolymer was used for the adsorption of Hg(II) ions from its aqueous solution. The operating variables affecting the Hg(II) adsorption, including the solution pH, amount of sulfated graft copolymer, contact time, and concentration of Hg(II), were investigated extensively. The sulfated graft copolymer was also used for competitive metal-ion removal with Pb(II), Cd(II), Cu(II), and Zn(II). Metal complexation was studied with FTIR spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, and cyclic voltammetry analysis. The Hg(II) adsorption data of the sulfated graft copolymer were described well by the pseudo-second-order rate equation. The Langmuir adsorption isotherm provided the best correlation for the adsorption data. Various thermodynamic parameters for the adsorption were calculated. FTIR and UV–vis spectroscopy and cyclic voltammetry analysis before and after the adsorption of Hg(II) on the sulfated graft copolymer showed that columbic attraction was mainly responsible for the binding of the Hg(II) ions with the  groups present in the sulfated graft copolymer. The sulfated graft copolymer showed a better adsorption performance than the graft copolymer itself under optimized conditions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44565.     

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     

Synthesis of poly(acrylamide‐co‐4‐vinylpyridine) hydrogels and their application in heavy metal removal

A series of poly(acrylamide‐co‐4‐vinylpyridine) hydrogels having varied acrylamide/4‐vinylpyridine content and different crosslink ratios of N,N′‐methylene‐bisacrylamide was prepared by using solution polymerization. The prepared hydrogel polymers were characterized by their elemental analysis, infrared spectroscopy, and equilibrium water content. The polymers were investigated toward metal ion uptake of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). The polymers were more sensitive to Cu(II) and Ni(II) and the order of metal ion binding was Ni(II), Cu(II) > Zn(II) > Co(II) > Mn(II). Metal ion uptake by the polymers was reduced as the pH of the medium decreased. Recycling of the resins resulted in high recovery of the metal ions from their aqueous solutions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2522–2526, 2003     

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     

Determination of the competitive adsorption of heavy metal ions on poly(n‐vinyl‐2‐pyrrolidone/acrylic acid) hydrogels by differential pulse polarography

Poly(N‐vinyl‐2‐pyrrolidone) and poly(N‐vinyl‐2‐pyrrolidone/acrylic acid) hydrogels were prepared by gamma irradiation for the removal of heavy metal ions (i.e., lead, copper, zinc, and cadmium) from aqueous solutions containing different amounts of these ions (2.5–10 mg/L) and at different pH values (1–13). The observed affinity order in adsorption of these metal ions on the hydrogels was Zn(II) > Pb(II) > Cu(II) > Cd(II) under competitive conditions. The optimal pH range for the heavy metal ions was from 7 to 9. The adsorption of the heavy metal ions decreased with increasing temperature in both water and synthetic seawater conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2013–2018, 2003     

Analytical applications of newly synthesized copolymer resin derived from p‐aminophenol,dithiooxamide, and formaldehyde

A copolymer resin (p‐APDF) has been synthesized using the monomers p‐aminophenol, dithiooxamide, formaldehyde in 1 : 1 : 2M proportions in the presence of 2M HCl as catalyst. The structure of p‐APDF copolymer has been elucidated on the basis of elemental analysis and various physicochemical techniques, i.e., UV‐visible, FTIR, and ¹H‐NMR spectroscopy. The number average molecular weight of copolymer resin was determined by nonaqueous conductometric titration in DMF. Viscosity measurement were carried out in DMF indicate normal behavior. The prepared resin proved to be a selective ion exchange resin for some metal ions. The chelating ion exchange properties of this resin was studied for Fe(III) and Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Pb(II) ions. A batch equilibrium method was used to study selectivity of metal ion uptake over a wide pH range and in media of various ionic strength. The resin showed a higher selectivity for Fe(III), Ni(II), Cu(II) ions than for Co(II), Pb(II), Zn(II), and Cd(II) ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Nickel and copper removal study from aqueous solution using new cationic poly[acrylamide/N,N‐DAMB/N,N‐DAPB] super absorbent hydrogel

A new cationic poly[acrylamide/N,N‐diallyl morpholinium bromide/N,N‐diallyl piperidinium bromide] super absorbent hydrogels (H1–H7) were prepared via microwave irradiated free radical cyclopolymerization using different composition. By the swelling study, hydrogel H1 is found to bear good swelling properties amongst all prepared hydrogels. The hydrogel H1 has been characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), and TGA analysis. A batch system was applied to study the adsorption of Ni(II) and Cu(II) from aqueous solutions by hydrogel H1. The effect of treatment time, pH of the medium, amount of adsorbent doses, and initial feed concentration of metal ion on adsorption of Ni(II) and Cu(II) from their solution were also investigated. Adsorption of Ni(II) and Cu(II) increases with the increase in treatment time, adsorbent doses, and initial feed concentration and decreases with the increase in pH of the medium. The desorption of metal ions were carried out using 1N HCl and 0.5N H₂SO_4. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of the nature of the crosslinking agent on the metal‐ion complexation characteristics of 4 mol % DVB‐ and NNMBA‐crosslinked polyacrylamide‐supported glycines

Metal‐ion complexation behavior of glycine functions supported on divinylbenzene (DVB)‐ and N,N′‐methylene bisacrylamide (NNMBA)‐crosslinked polyacrylamide was carried out toward Co(II), Ni(II), Cu(II), and Zn(II) ions. The polymeric ligands and the derived metal complexes were characterized by IR, UV, and EPR spectra and by SEM. The metal‐ion complexation of the rigid DVB‐crosslinked system is lower than that of the semirigid NNMBA‐crosslinked system. The glycine ligands renervated after the desorption of the metal ions showed an unusual specificity toward the desorbed metal ion. The low degree of crosslinking makes the desorption process simple and shows fast rebinding kinetics. The metal‐ion‐desorbed polymeric ligands would have pockets or holes characteristic of the desorbed metal ion, resulting in its specific rebinding. The rigidity of the crosslinking also determines the kinetics of metal‐ion rebinding. The specificity and selectivity characteristics of the crosslinked polymeric ligand was found to be increased as the crosslinking agent changes from semirigid NNMBA to rigid and hydrophobic DVB. Thus, copper‐desorbed resins showed an increased specificity toward copper ions and selectively binds copper ions from a mixture of copper and cobalt ions. The metal‐ion specificity and selectivity characteristics of the metal‐ion‐desorbed system is exploited for the concentration of desorbed metal ions from a mixture of metal ions. The resin is amenable for a continuous process and can be regenerated several times. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3432–3444, 1999     

Preparation of poly(4‐vinylpyrrolidone)‐g‐poly(N‐hydroxyacrylamide) and study of its metal binding properties

Crosslinked poly(N‐vinylpyrrolidone), preirradiated in air with γ rays, was grafted with ethyl acrylate in dioxane and water. A detailed study of grafting was made under various reaction conditions. The graft copolymer was treated with potassium hydroxamate in ethanol. The resulting polymer contained pendant hydroxamic acid groups ( CO NHOH) and was studied for the formation of complexes with Fe(III), Cu(II), and Ni(II). The effect of pH on the metal ion uptake by the polymer was also studied. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 475–483, 2000     

Metal ion interaction of water‐soluble copolymers containing carboxylic acid groups in aqueous phase by membrane filtration technique

This article reports the synthesis of poly(N‐maleoylglycine‐co‐itaconic acid) by radical copolymerization under different feed mole ratios and its properties to remove various metal ions, such as Cu(II), Cr(III), Co(II), Zn(II), Ni(II), Pb(II), Cd(II), and Fe(III), in aqueous phase with the liquid‐phase polymer‐based retention(LPR) technique. The interactions of inorganic ions with the hydrophilic water‐soluble polymer were determined as a function of pH and filtration factor. Metal ion retention was found to strongly depend on the pH. Metal ion retention increased as pH and MG content units in the macromolecular backbone increased. The copolymers were characterized by elemental analysis, FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. Additionally, intrinsic viscosity, molecular weight, and polydispersity have been determined for the copolymers. Copolymer and polymer–metal complex thermal behavior was studied using differential scanning calorimetry (DSC) and thermogravimetry (TG) techniques under nitrogen atmosphere. The thermal decomposition temperatures (TDT) were influenced by the copolymer composition. The copolymers present lower TDT than the polymer–metal complex with the same copolymer composition. All copolymers present a single T_g, indicating the formation of random copolymers. A slight deviation of the T_g for the copolymers and its complexes can be observed. The copolymer T_g is higher than the T_g value for the polymer–metal complexes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Investigation on selective adsorption of Hg(II) ions using 4‐vinyl pyridine grafted poly(ethylene terephthalate) fiber

In the work, poly(ethylene terephthalate) (PET) fibers were grafted with 4‐vinyl pyridine (4‐VP) monomer using benzoyl peroxide (Bz₂O₂) as initiator in aqueous media. The removal of Hg(II) ions from aqueous solution by the reactive fiber was examined by batch equilibration technique. Effects of various parameters such as pH, graft yield, adsorption time, initial ion concentration, and adsorption temperature on the adsorption amount of metal ions onto reactive fibers were investigated. The optimum pH of Hg(II) was found 3. The maximum adsorption capacity was found as 137.18 mg g^?1. Moreover such parameters as the adsorption kinetics, the adsorption isotherm, desorption time and the selectivity of the reactive fiber were studied. The adsorption kinetics is in better agreement with pseudo‐first order kinetics, and the adsorption data are good fit with Freundlich isotherms. The grafted fiber is more selective for Hg(II) ions in the mixed solution of Hg(II)‐Ni(II), Hg(II)‐Zn(II), and Hg(II)‐Ni(II)‐Zn(II) at pH 3. Adsorbed Hg(II) ions were easily desorbed by treating with 1M HNO₃ at room temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Interpolymer‐specific interactions and miscibility in poly(styrene‐co‐acrylic acid)/poly(styrene‐co‐N,N‐dimethylacrylamide) blends

The miscibility or complexation of poly(styrene‐co‐acrylic acid) containing 27 mol % of acrylic acid (SAA‐27) and poly(styrene‐co‐N,N‐dimethylacrylamide) containing 17 or 32 mol % of N,N‐dimethylacrylamide (SAD‐17, SAD‐32) or poly(N,N‐dimethylacrylamide) (PDMA) were investigated by different techniques. The differential scanning calorimetry (DSC) analysis showed that a single glass‐transition temperature was observed for all the mixtures prepared from tetrahydrofuran (THF) or butan‐2‐one. This is an evidence of their miscibility or complexation over the entire composition range. As the content of the basic constituent increases as within SAA‐27/SAD‐32 and SAA‐27/PDMA, higher number of specific interpolymer interactins occurred and led to the formation of interpolymer complexes in butan‐2‐one. The qualitative Fourier transform infrared (FTIR) spectroscopy study carried out for SAA‐27/SAD‐17 blends revealed that hydrogen bonding occurred between the hydroxyl groups of SAA‐27 and the carbonyl amide of SAD‐17. Quantitative analysis carried out in the 160–210°C temperature range for the SAA‐27 copolymer and its blends of different ratios using the Painter–Coleman association model led to the estimation of the equilibrium constants K₂, K_A and the enthalpies of hydrogen bond formation. These blends are miscible even at 180°C as confirmed from the negative values of the total free energy of mixing ΔG_M over the entire blend composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1011–1024, 2007     

Studies on the Complexation of 3d Transition Metal Ions with NR/PEO Block Copolymer in Aqueous Medium

Polyethylene oxide (PEO) was chemically linked to natural rubber (NR) segments to form a block copolymer (BC), which proved to be a suitable material for complexing with selected first row transition metal ions in aqueous solution through batch adsorption method under noncompetitive mode. Optimum conditions for sorption were found to be 20 mmol/L initial concentration, pH at 6, ambient temperature, and 24 h. The order of decreasing adsorption capacity obtained is Mn(II) > Co(II) > Zn(II) > Ni(II) > Cu(II) > Fe(III). Freundlich isotherm shows the best fit indicating that the adsorption is of heterogeneous in nature. The complexation follows pseudo second-order kinetics. Exothermic character of the complexation was confirmed by thermodynamic study. For all metal ions, the standard free energy change values are negative for the different temperatures studied, which confirms the spontaneous character of the process. At ambient temperature, the free energy change lies between −2.35 and − 7.83 kJ/mol for all complexes. Values of activation energy for all the metal ion complexation is within the range 11–25 kJ/mol, which indicates chemical interaction via activated physico–chemical adsorption. Variation in stability constant of the complexes also follows the same order as given above. POLYM. ENG. SCI., 60:661–672, 2020. © 2020 Society of Plastics Engineers     

Preparation,characterization, and metal ion retention capacity of Co(II) and Ni(II) from poly(p‐HO‐ and p‐Cl‐phenylmaleimide‐co‐2‐hydroxypropylmethacrylate) using the ultra filtration technique

p‐Chlorophenylmaleimide and p‐hydroxyphenylmaleimide with 2‐hydroxypropyl methacrylate were synthesized by radical polymerization, and the metal ion retention capacity and thermal behavior of the copolymers were evaluated. The copolymers were obtained by solution radical polymerization with a 0.50 : 0.50 feed monomer ratio. The maximum retention capacity (MRC) for the removal of two metal ions, Co(II) and Ni(II) in aqueous phase were determined using the liquid‐phase polymer based retention technique. Inorganic ion interactions with the hydrophilic polymer were determined as a function of pH. The metal ion retention capacity does not depend strongly on the pH. Metal ion retention increased with an increase of pH for a copolymer composition 0.50 : 0.50. At different pH, the MRC of the poly(p‐chlorophenylmaleimide‐co‐2‐hydroxypropylmethacrylate) for Co(II) and Ni(II) ions varied from 44.1 to 48.6 mg/g and from 41.5 mg/g to 46.0 mg/g, respectively; while the MRC of poly(p‐hydroxyphenylmaleimide‐co‐2‐hydroxypropyl methacrylate) for Co(II) and Ni(II) ions varied from 28.4 to 35.6 mg/g and from 27.2 to 30.8 mg/g, respectively. The copolymers and copolymer–metal complexes were characterized by elemental analysis, FT‐IR, ¹H NMR spectroscopy, and thermal behavior. The thermal behavior of the copolymer and polymer–metal complexes were studied using differential scanning calorimetry and thermogravimetry techniques under nitrogen atmosphere. The thermal decomposition temperature and T_g were influenced by the binding‐metal ion on the copolymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Thermal properties of poly(maleic anhydride‐alt‐acrylic acid) in the presence of certain metal chlorides

Polychelates were synthesized by the addition of aqueous solutions of copper(II), cadmium(II), and nickel(II) chlorides to aqueous solutions of poly(maleic anhydride‐alt‐acrylic acid) [poly(MA‐alt‐AA)] in different pH media. The thermal properties of poly(MA‐alt‐AA) and its metal complexes were investigated with thermogravimetry and differential scanning calorimetry (DSC) measurements. The polychelates showed higher thermal stability than poly(MA‐alt‐AA). The thermogravimetry of the polymer–metal complexes revealed variations of the thermal stability by complexation with metal ions. The relative thermal stabilities of the systems under investigation were as follows: poly(MA‐alt‐AA)–Cd(II) > poly(MA‐alt‐AA)–Cu(II) > poly(MA‐alt‐AA)–Ni(II) > poly(MA‐alt‐AA). The effects of pH on the complexation and gravimetric analysis of the polychelates were also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3926–3930, 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     

“Smart” membrane materials: Preparation and characterization of PVDF‐g‐PNIPAAm graft copolymer

In this research, a smart membrane material of graft copolymer of poly(vinylidene fluoride) with poly(N‐isopropylacrylamide) (PVDF‐g‐PNIPAAm) was synthesized by atom transfer radical polymerization (ATRP) using poly(vinylidene fluoride) (PVDF) as a macroinitiator and direct initiation of the secondary fluorinated site PVDF facilitates grafting the N‐isopropylacrylamide comonomer. The copolymers were characterized by Fourier transform infrared (FTIR), ¹H NMR, gel‐permeation chromatography (GPC), and X‐ray photoelectron spectroscopy (XPS). The temperature‐sensitive membrane was prepared from the PVDF‐g‐PNIPAAm graft copolymers by the phase inversion method. The effects of temperature on the flux of pure water of membrane was investigated. The results showed that alkyl fluorides were successfully applied as ATRP initiators in the synthetic condition and the flux of pure water through the PVDF‐g‐PNIPAAm membrane depended on the temperature change. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1482–1486, 2007     

Synthesis and metal ion adsorption studies of chelating resins derived from macroporous glycidyl methacrylate‐divinylbenzene copolymer beads anchored schiff bases

Two novel chelating resins are prepared by anchoring diethylenetriamine bis‐ and mono‐furaldehyde Schiff bases onto the macroporous GMA‐DVB copolymer beads and utilized for the adsorption towards Cu(II), Co(II), Ni(II), and Zn(II). FTIR spectra show that Schiff base groups have been successfully introduced into the polymer matrix and the chelating resins can form complexes with the metal ions. The chelating resins show a higher adsorption capacity toward Cu(II). The conductivity method can be used for determining the adsorption kinetics of the resins towards metal ions. The results show that the adsorption rates towards Cu(II) are much higher than those towards other ions and pseudo second‐order and intraparticle diffusion models can be applied to treat the adsorption amount‐time data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

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

The free‐radical copolymerization of water‐soluble poly(1‐vinyl‐2‐pyrrolidone‐co‐hydroxyethylmethacrylate) was carried out with a feed monomer ratio of 75:25 mol %, and the total monomer concentration was 2.67M. The synthesis of the copolymer was carried out in dioxane at 70°C with benzoyl peroxide as the initiator. The copolymer composition was obtained with elemental analysis and ¹H‐NMR spectroscopy. The water‐soluble polymer was characterized with elemental analysis, Fourier transform infrared, ¹H‐ and ¹³C‐NMR spectroscopy, and thermal analysis. Additionally, viscosimetric measurements of the copolymer were performed. The thermal behavior of the copolymer and its complexes were investigated with differential scanning calorimetry (DSC) and thermogravimetry techniques under a nitrogen atmosphere. The copolymer showed high thermal stability and a glass transition in the DSC curves. The separation of various metal ions by the water‐soluble poly(1‐vinyl‐2‐pyrrolidone‐co‐hydroxyethylmethacrylate) reagent in the aqueous phase with liquid‐phase polymer‐based retention was investigated. The method was based on the retention of inorganic ions by this polymer in a membrane filtration cell and subsequent separation of low‐molar‐mass species from the polymer/metal‐ion complex formed. Poly(1‐vinyl‐2‐pyrrolidone‐co‐hydroxyethylmethacrylate) could bind metal ions such as Cr(III), Co(II), Zn(II), Ni(II), Cu(II), Cd(II), and Fe(III) in aqueous solutions at pHs 3, 5, and 7. The retention percentage for all the metal ions in the polymer was increased at pH 7, at which the maximum retention capacity could be observed. The interaction of inorganic ions with the hydrophilic polymer was determined as a function of the pH and filtration factor. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 178–185, 2006     

Temperature‐responsive alginate‐g‐poly(N,N‐diethylacrylamide) copolymer: Synthesis,characterization, and swelling behavior

Temperature‐responsive polymers have recently gained importance due to their applications in drug delivery. Herein, temperature‐responsive graft copolymer (Alg‐g‐PDEAAm) of alginate and N,N‐diethylacrylamide was synthesized by microwave‐assisted copolymerization using potassium persulfate/N,N,N′,N′‐tetramethylethylenediamine initiator system. The reaction conditions for the best grafting (331%) have been optimized by changing microwave irradiation time, temperature, N,N‐diethylacrylamide, and alginate concentrations. The spectroscopic characteristic, thermal properties, and surface morphology of the copolymers were investigated by FTIR, ¹H‐NMR, DSC/TGA, XRD, gel permeation chromatography, and SEM. Furthermore, low critical solution temperatures of Alg‐g‐PDEAAm copolymers were detected by UV spectroscopy. Swelling ratio of graft microspheres was carried out at 25, 32, and 37 °C, and microspheres were found exhibiting temperature‐responsive property. Cytotoxicity test indicated the Alg‐g‐PDEAAm copolymer and its microsphere were biocompatible. Therefore, based on the results the synthesized temperature‐responsive copolymer could be considered as a promising biomaterial. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46688.