Preparation of sorbitol from D‐glucose hydrogenation in gas–liquid–solid three‐phase flow airlift loop reactor

A new process for D ‐glucose hydrogenation in 50 wt% aqueous solution, into sorbitol in a 1.5 m³ gas–liquid–solid three‐phase flow airlift loop reactor (ALR) over Raney Nickel catalysts has been developed. Five main factors affecting the reaction time and molar yield to sorbitol, including reaction temperature (T_R), reaction pressure (P_R), pH, hydrogen gas flowrate (Q_g) and content of active hydrogen, were investigated and optimized. The average reaction time and molar yield were 70 min and 98.6% under the optimum operating conditions, respectively. The efficiencies of preparation of sorbitol between the gas–liquid–solid three‐phase flow ALR and stirred tank reactor (STR) under the same operating conditions were compared. Copyright © 2004 Society of Chemical Industry     

Separation of α‐Lactalbumin and β‐Lactoglobulin by a Convenient Liquid‐Solid Extraction System: Application to Milk Whey

A liquid‐solid extraction system based on Tween 80/phosphate was developed. Under the optimized conditions (9 wt % Tween 80, 1.6 : 1 (molar ratio) K₂HPO₄ : NaH₂PO₄, 1.25 mol/L total phosphate, pH = 7.4), α‐Lactalbumin (α‐La) and β‐Lactoglobulin (β‐Lg) were separated with recovery rates of 87.6 % (in the solid polymeric phase) and 98.2 % (in the salt aqueous phase), respectively. Under the effects of water and salt, the solid phase had the ability to form a new liquid‐solid extraction system, and 85.1 % of α‐La could be reversely extracted into the new salt aqueous phase. Following dialysis against water, proteins obtained through extraction and reverse extraction, were analyzed by polyacrylamide gel electrophoresis (PAGE) and thin‐layer scanning. The method was applied successfully to separate α‐La and β‐Lg from milk whey.     

Enhancing separation of titanium and iron by three‐liquid‐phase extraction with 1,10‐phenanthroline as additive

BACKGROUND: A three‐liquid‐phase system (TLPS) composed of an organic solvent‐rich top phase, a polymer‐rich middle phase and a salt‐rich bottom phase is a newly emerging separation medium. Due to low affinity of the polymer‐rich phase for metals it is necessary and important to search for a suitable complexing agent that has a definite affinity for the polymer‐rich middle phase and a high selectivity for the metal ion of interest. RESULTS: Addition of 1,10‐phenanthroline (phen) is effective in enhancing the separation of titanium and iron from magnesium in the TLPS consisting of trialkylphosphine oxide (TRPO)‐PEG 2000‐(NH₄)₂SO₄. Hydrogen‐bonding interactions between PEG 2000 and phen molecules are the driving force for anchoring tri(phen)‐iron(II) sulfate complexes in the middle phase. Under the conditions (pH = 1.5, molar ratio of phen to iron(II) = 3.4:1), nearly 86% of titanium was extracted into the top phase while 100% of iron(II) was distributed in the middle phase, without any interference between the metal species. The separation factor of titanium and iron in the upper two phases was greater than 20 000. CONCLUSIONS: A single step of extraction and separation of titanium and iron from magnesium was realized in the TRPO‐PEG 2000‐(NH₄)₂SO₄ TLPS with phen as additive. It highlights the effectiveness of TLPS in dealing with multi‐metal solutions and suggests a potential use of TLPS in the separation of iron and other target metals. As iron is ubiquitous the separation of iron is often needed in both analytical processes and the hydrometallurgical industry. Copyright © 2012 Society of Chemical Industry     

Cobalt removal from waste‐water by means of supported liquid membranes

BACKGROUND: Supported liquid membranes (SLM) are an alternative technique to remove and recover metals from diluted process solutions and waste‐water. In the present work, the removal of Co(II) from a synthetic CoSO₄ solution containing initial amounts of cobalt(II) in the range 100–200 ppm (0.1–0.2 g dm^?3) has been studied on a pilot scale. By performing batch equilibrium experiments, the optimal settings, i.e. the composition of the organic phase, the pH of the feed, the type and concentration of the stripping agent were determined. RESULTS: It is shown that the equilibrium characteristics of a synergistic extractant mixture containing di‐2‐ethyl‐hexylphosphoric acid (D2EHPA) and 5‐dodecylsalicylaldoxime (LIX 860‐I) are superior to D2EHPA. Both hydrochloric acid and sulfuric acid have been evaluated as stripping solutions in liquid–liquid extraction tests and as the receiving phase in a SLM configuration. Although equilibrium tests showed no difference in stripping characteristics between both chemicals, it was observed that in a SLM configuration the stability of the system when hydrochloric acid is used is poor. With a commercially available SLM module (Liqui‐Cel Extra‐Flow 4 × 28) having a surface area of 19 m², a steady Co(II) flux of 0.140 gm^?2h^?1 has been obtained at influent concentrations of cobalt between 100 and 200 ppm with 3 mol dm^?3 sulfuric acid as stripping phase. CONCLUSIONS: The results obtained show that a supported liquid membrane containing a synergistic mixture of LIX 860‐I and D2EHPA gives the possibility of recovering cobalt from dilute solutions. Copyright © 2008 Society of Chemical Industry     

Removal of Copper(II) from a Concentrated Sulphate Medium by Cloud Point Extraction Using an N,N′-Bis(salicylaldehyde)Ethylenediimine Di-Schiff Base Chelating Ligand

Various chelating ligands have been investigated for the cloud point extraction of several metal ions. However, limited studies on the use of the Schiff base ligands have been reported. In this work, cloud point extraction behavior of copper(II) with N,N′‐bis(salicylaldehyde)Ethylenediimine Schiff base chelating ligand, (H₂SALEN), was investigated in aqueous concentrated sulphate medium. The extraction process used is based on the formation of hydrophobic H₂SALEN–copper(II) complexes that are solubilized in the micellar phase of a non‐ionic surfactant, i.e. ethoxylated (9.5EO) tert‐butylphenol. The copper(II) complexes are then extracted into the surfactant‐rich phase above cloud point temperature. Different parameters affecting the extraction process of Cu(II), such as equilibrium pH, extractant concentration, and non‐ionic surfactant concentration were explored. The extraction of Cu(II) was studied in the pH range of 2–11. The results obtained showed that it was profoundly influenced by the pH of the aqueous medium. The concentration factor, C_f, of about 17 with extraction efficiency of E % ≈100 was achieved. The stoichiometry of the extracted complex of copper(II) was ascertained by the Yoe–Jones method to give a composition of 1:1 (Cu:H₂L). The optimum conditions of the extraction‐removal have been established as the following: (1) 1.86 × 10^?3 mol/L ligand; (2) 3 wt% surfactant; (3) pH of 8 (4) 0.5 mol/L Na₂SO₄ and (5) temperature of 60 °C.     

Solvent extraction separation of vanadium(V) from multivalent metal chloride solutions using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester

The solvent extraction behaviour of vanadium(V) from hydrochloric acid solutions has been investigated using 2‐ethylhexyl phosphonic acid mono‐2‐ethylhexyl ester (EHEHPA ≡ HX) in kerosene as an extractant. For comparison, extraction studies have also been carried out with vanadium(IV). The results demonstrate that the extraction of vanadium(V) follows the cation exchange mechanism: where (HX)₂ refers to the dimeric form of EHEHPA. On the other hand, two dimeric molecules of EHEHPA were found to be involved in the extracted complex of vanadium(IV): The equilibrium constants of the above extracted complexes have been calculated and found to be K_ex,V(V) = 3.14 and K_ex,V(IV) = 0.32. The effect of the nature of the diluent on the extraction of vanadium(V) with EHEHPA has been studied and correlated with the dielectric constants. IR spectral studies of the extracted complex were used to further clarify the nature of the extracted complex. The separation and recovery possibilities of vanadium(V) from other associated metal ions, viz magnesium(II), aluminium(III), titanium(IV), chromium(III), manganese(II) and iron(III), which are present in the waste chloride liquors from the processing of titanium minerals, are also discussed. © 2002 Society of Chemical Industry     

Solvent extraction studies of Sm(III) from nitrate medium and separation factors of rare earth elements with mixtures of sec‐octylphenoxyacetic acid and 1,10‐phenthroline

BACKGROUND: Liquid–liquid extraction is widely used for the separation of rare earths, among which synergistic extraction has attracted more and more attention. Numerous types of synergistic extraction systems have been applied to rare earths with high extraction efficiency and selectivities. In the present study, mixtures of sec‐octylphenoxyacetic acid (CA12, H₂A₂) and 1,10‐phenanthroline (phen, B) have been used for the extraction of rare earths from nitrate medium. The stoichiometry of samarium(III) extraction has been studied using the methods of slope analysis and constant molar ratio. The possibility of using synergistic extraction effects to separate rare earths has also been studied. RESULTS: Mixtures of CA12 and phen display synergistic effects in the extraction of rare earth elements giving maximum enhancement coefficients of 5.5 (La); 13.7 (Nd); 15.9 (Sm); 24.5 (Tb); 45.4 (Yb) and 12.3 (Y). Samarium(III) is extracted as SmHA₄B₃ with mixtures of CA12 and phen instead of SmHA₄ when extracted with CA12 alone. The calculated logarithm of the equilibrium constant is 6.0 and the thermodynamic functions, ΔH, ΔG, and ΔS, have been calculated as 4.3 kJ mol^?1, ? 33.7 kJ mol^?1 and 129.7 J mol^?1 K^?1, respectively. CONCLUSION: Mixtures of CA12 and phen exhibit synergistic effects on rare earth elements. Graphical and numerical methods have been successfully used to determine their stoichiometries. The different synergistic effects may provide the possibility of separating yttrium from heavy lanthanoids at an appropriate ratio of CA12 and phen. Copyright © 2010 Society of Chemical Industry     

Recovery of zinc,cadmium and mercury (ii) from chloride and sulphate media by solvent extraction

The extraction of zinc, cadmium and mercury from chloride and sulphate media by solvating extractants, liquid anion and liquid cation exchangers has been reviewed both from the literature and by experiment. The results have been discussed in terms of both practical process possibilities and the use of slope analysis to identify the extracted species. These show that slope analysis cannot give positive unambiguous identification of extraction stoichiometry in systems in which the extracted metal species contains coordinating ligands from the aqueous phase. However, in the extraction of Zn and Cd from sulphate media by di(2-ethylhexyl)phosphoric acid (DEHPA) the extracted species is shown to be an MR₂(HR)₂ monomer by slope analysis demonstrating its use in simple systems. In the case of amines and solvating reagents such as TBP^c and TOPO zinc appears to be extracted from Cl^– media as either ZnCl₂ or sometimes HZnCl₃ whereas Cd and Hg(II) appear to be always extracted as HCdCl₃ and HHgCl₃ species. The use of aqueous phase complexing by Cl^– to improve the separation of Zn and Cd by extraction is clear. Some results are presented for the recovery of zinc from sulphate media by oximes and mercury from sulphuric acid media by amines and DEHPA.     

Equilibrium and kinetic studies on the extraction of gadolinium(III) from nitrate medium by di‐2‐ethylhexylphosphoric acid in kerosene using a single drop technique

The liquid–liquid extraction of Gd(III) from aqueous nitrate medium was studied using di‐2‐ethylhexylphosphoric acid (HDEHP) in kerosene. On the basis of the slope analysis data, the composition of the extracted species was found to be [Gd A₃(HA)] with the extraction equilibrium constant (K_ex) = (1.48 ± 0.042) × 10^?12 mol dm^?3. The results of the effect of temperature on the value of the equilibrium extraction constant indicated the endothermic character of the extraction system. The kinetics of the forward extraction of Gd³⁺ from nitrate medium by HDEHP in kerosene was investigated using the single drop column technique. The rate of flux (mass transfer per unit area) was found to be proportional to [Gd(III)], [H₂A₂]_(o), [NO₃^?], and [H⁺]^?1 in the liquid drop organic phase. The forward extraction rate constant, k_f, was 2.24 × 10^?3 m s^?1 using the equation: Copyright © 2005 Society of Chemical Industry     

Deep oxidative–extractive desulfurization of fuels using benzyl‐based ionic liquid

Four benzyl‐based ionic liquids (ILs) were synthetized and used for deep desulfurization of model oil and real diesel fuel. The removal efficiencies of benzothiophene (BT) and dibenzothiophene (DBT) with [Bzmim][NTf₂] and [Bzmim][SCN] as extractants are higher than that with [Bzmp][NTf₂] and [Bzmp][SCN] as extractants. The desulfurization capability follows the Nernst's Law. A reactive extraction mathematical model for desulfurization was established. An oxidative‐extractive two‐step deep desulfurization method was developed. DBT was first oxidized by H₂O₂ with CH₃COOH as catalyst and then the unoxidized DBT and uncrystallized dibenzothiophene sulfoxide (DBTO₂) in model oil were extracted by [Bzmim][NTf₂], and finally the removal efficiency was 98.4% after one‐stage extraction. Besides, the removal efficiency of 4,6‐DMDBT was 96.4% after oxidation and one‐stage extraction processes. Moreover, the oxidative‐extractive two‐step deep desulfurization method was also effective for desulfurization of diesel fuel. The removal efficiency of sulfur reached up to 96% after oxidation and three‐stage cross‐current extraction processes. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4023–4034, 2016     

Solvent extraction of some metal ions with di‐2‐methylnonylphosphoric acid into heptane

Di‐2‐methylnonylphosphoric acid (HA) as an extractant was investigated for the extraction of divalent metal ions into heptane at an aqueous ionic strength of 0.10 mol dm^?3 (NaClO₄) and at 25 °C. The extraction ability of metal complexes decreased in the order Cd(II) ≈ Mn(II) > Cu(II) > Co(II) > Ni(II). The metal complexes extracted were found to be all monomeric species for these metal ions using a slope analysis method. The curve fitting method was also applied to analyze the types of metal complexes extracted: MnA₂3HA and MnA₂4HA for manganese(II), CdA₂3HA and CdA₂4HA for cadmium(II), CuA₂2HA and CuA₂3HA for copper(II), CoA₂3HA and CoA₂4HA for cobalt(II) and NiA₂4HA and NiA₂5HA for nickel(II). Further, the extraction constants for the extracted metal complexes were evaluated. © 2002 Society of Chemical Industry     

Synergistic extraction of rare earths(III) from chloride medium with mixtures of 1‐phenyl‐3‐methyl‐4‐benzoyl‐pyrazalone‐5 and di‐(2‐ethylhexyl)‐2‐ethylhexylphosphonate

The synergistic effect of 1‐phenyl‐3‐methyl‐4‐benzoyl‐pyrazalone‐5 (HPMBP, HA) and di‐(2‐ethylhexyl)‐2‐ethylhexylphosphonate (DEHEHP, B) in the extraction of rare earths (RE) from chloride solutions has been investigated. Under the experimental conditions used, there was no detectable extraction when DEHEHP was used as a single extractant while the amount of RE(III) extracted by HPMBP alone was also low. But mixtures of the two extractants at a certain ratio had very high extractability for all the RE(III). For example, the synergistic enhancement coefficient was calculated to be 9.35 for Y³⁺, and taking Yb³⁺ and Y³⁺ as examples, RE³⁺ is extracted as RE(OH)A₂.B. The stoichiometry, extraction constants and thermodynamic functions such as Gibbs free energy change ΔG (?17.06 kJ mol^?1), enthalpy change ΔH (?35.08 kJ mol^?1) and entropy change ΔS (?60.47 J K^?1 mol^?1) for Y³⁺ at 298 K were determined. The separation factors (SF) for adjacent pairs of rare earths were calculated. Studies show that the binary extraction system not only enhances the extraction efficiency of RE(III) but also improves the selectivity, especially between La(III) and the other rare earth elements. Copyright © 2006 Society of Chemical Industry     

Novel and Mild Route to Phthalocyanines and 3‐Iminoisoindolin‐1‐ones via N,N‐Diethylhydroxylamine‐Promoted Conversion of Phthalonitriles and a Dramatic Solvent‐Dependence of the Reaction

Refluxing a mixture of phthalonitrile C₆R¹R²R³R⁴(CN)₂ 1 (R¹–R⁴=H), or its substituted derivatives 2 (R¹, R³, R⁴=H, R²=Me), or 3 (R¹, R⁴=H, R², R³=Cl) (1 equiv.) and N,N‐diethylhydroxylamine, Et₂NOH, (4 equivs.) in methanol for 4 h results ( Route A ) in precipitation of the symmetrical ( 6 and 8 ) and an isomeric mixture of unsymmetrical ( 7 ) phthalocyanines, isolated in good (55–65 %) yields. The reaction of phthalonitriles 1 , 2 , or 4 (R¹, R³, R⁴=H, R²=NO₂) (4 equivs.) with Et₂NOH (8 equivs.) in the presence of a metal salt MCl₂ (M=Zn, Cd, Co, Ni) (1 equiv.) in n‐BuOH or without solvent results in the formation of metallated phthalocyanine species ( 9 – 17 ). Upon refluxing in freshly distilled dry chloroform, phthalonitrile 1 or its substituted analogues 2 , 3 or 5 (R¹–R⁴=F) (1 equiv.) react with N,N‐diethylhydroxylamine (2 equivs.) affording 3‐iminoisoindolin‐1‐ones 18 – 21 ( Route B ) isolated in good yields (55–80 %). All the prepared compounds were characterized with C, H, and N elemental analyses, ESI‐MS, IR, and compounds 18 – 21 also by 1D (¹H, ¹³C{¹H}), and 2D (¹H,¹⁵N‐HMBC and ¹H,¹³C‐HMQC, ¹H,¹³C‐HMBC) NMR spectroscopy.     

Study on the extraction of dyes into a room‐temperature ionic liquid and their mechanisms

The investigation of liquid–liquid extraction of dyes is carried out by using ionic liquid—1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF₆])—as extraction phase. The effects of its process parameters are studied in detail, such as extraction phase ratio, pH of the aqueous phase, and concentration of dicyclohexyl‐18‐crown‐6 (DCH‐18C6) in the organic phase. Important results are obtained as follows: acid dyes can be extracted with [BMIM][PF₆] quantitatively; the removal of reactive dyes is low; however, it can be greatly increased by the addition of DCH‐18C6. The pH value has a great impact on the removal of the acid dye and the reactive dye. However, it does not influence the extraction of the weak acid dye. It is found that the extraction process of acid dyes adopts the form of anion exchange and the soluble part of the ionic liquid plays an important role as counter‐ions. Copyright © 2007 Society of Chemical Industry     

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     

The synthesis of oxime reagents from natural and semi‐synthetic phenolic lipid and alkanoic acid resources for the solvent recovery of copper(II)

In a study of the relationship between structure and efficiency towards recovery of copper(II) by chelation/solvent extraction, a series of homologous aldoximes has been synthesised from natural phenolic lipidic, and fatty lipidic renewable sources, for comparison with commercial reagents prepared from petrochemical sources. From cardanol, in technical cashew nut‐shell liquid, isoanacardic aldoxime, [2‐hydroxy‐4‐pentadec(en)yl]aldoxime, and from the natural phenolic lipid, anacardic acid, the isomer, 2‐hydoxy‐6‐pentadec(en)ylaldoxime, have been synthesised. A C₁₁ analogue of anacardic aldoxime from Anacardium giganteum has been prepared. The isomeric n‐octyl aldoximes have been synthesised, the o‐ and p‐isomers from the readily available fatty acid n‐octanoic acid and the m‐isomer from cardanol. Related m‐aldoximes have been prepared from the ketonic intermediates methyl isoamyl and methyl amyl ketones. The solvent extraction properties for copper(II) of the synthesised aldoximes have been compared with those of a current commercial reagent, 2‐hydroxy‐5‐t‐nonylbenzaldoxime (Acorga 5100, Cytec), and two former extractants, 2‐hydroxy‐5‐t‐nonylacetophenone ketoxime (SME 529, Shell) and 2‐hydroxy‐5‐t‐nonylbenzophenone ketoxime (LIX 65N, Henkel). All the aldoximes possessed useful properties in extraction efficiency, notably the isoanacardic and the C₈ aldoximes with the C₈o‐isomer, 2‐hydroxy‐3‐n‐octylbenzaldoxime, exhibited optimal extraction, stripping and phase separation characteristics. Copyright © 2005 Society of Chemical Industry     

Influence of Solvent Polarity on the Mechanism and Efficiency of Formic Acid Reactive Extraction with Tri‐n‐Octylamine from Aqueous Solutions

The reactive extractions of formic acid with tri‐n‐octylamine (TOA) dissolved in three solvents with different dielectric constants (dichloromethane, butyl acetate, n‐heptane) without and with 1‐octanol as phase modifier were comparatively analyzed. The results indicated that the mechanism of the interfacial reaction between acid and extractant (Q) is controlled by the organic phase polarity. In the absence of 1‐octanol, the structures of the extracted complexes are (HA)₂Q₂ for dichloromethane and butyl acetate, and (HA)₂Q₄ for n‐heptane. These structures are modified by adding 1‐octanol and become (HA)₂Q for extraction in dichloromethane or butyl acetate, and (HA)₂Q₂ for extraction in n‐heptane. Although the presence of 1‐octanol improves the extraction efficiency, it leads to a reduction of the extraction constants for all considered solvents, an influence that is more significant for n‐heptane.     

Kinetics of azo‐initiated 1‐vinyl‐2‐pyrrolidone polymerizations at low conversions in aqueous media

The free‐radical polymerization behavior of 1‐vinyl,2‐pyrrolidone (NVP) was studied at low conversions, using capillary dilatometry. The aqueous media were kept at neutral pH and the studies were conducted isothermally, at 40 or 45°C. The azo‐type initiators used were 4,4′‐azobis‐4‐cyanopentanoic acid (ACPA), 2,2′‐azobisisobutyronitrile (AZBN), and 2,2′‐azobis[2‐(2‐imidazolin‐2‐yl)propane dihydrochloride] (ABDH). The monomer concentration and initiator concentration ranges were 1.17–2.34 mol L⁻¹ and 1–8 mmol L⁻¹, respectively. The rates of polymerization (R_p) and orders of reaction with respect to NVP and the initiator were evaluated and the kinetic equations were found to be R_p ∝ [NVP] [ACPA]^1.2; R_p ∝ [NVP] [AZBN]^1.1; and R_p ∝ [NVP]^2.2 [ABDH]^1.1. The polymers obtained were characterized by their viscosity numbers and correlation of the viscosity average molecular weights made with the type and amount of the azo initiator. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 239–246, 2000     

Liquid–liquid extraction of cadmium(II) by Cyanex 923 and its application to a solid‐supported liquid membrane system

The extraction of cadmium(II) by Cyanex 923 (a mixture of alkylphosphine oxides) in Solvesso 100 from hydrochloric acid solution has been investigated. The extraction reaction is exothermic. The numerical analysis of metal distribution data suggests the formation of CdCl₂.2L, HCdCl₃.2L and H₂CdCl₄.2L (L = ligand) in the organic phase. The results obtained for cadmium(II) distribution have been implemented in a solid‐supported liquid membrane system. The influences of feed phase stirring speed (400–1400 min^?1), membrane composition (carrier concentration: 0.06–1 mol dm^?3) and metal concentration (0.01–0.08 g dm^?3) on cadmium transport have been investigated. Copyright © 2005 Society of Chemical Industry     

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